JP4060756B2 - Secondary battery charging method, charging device and charging control program therefor - Google Patents

Secondary battery charging method, charging device and charging control program therefor Download PDF

Info

Publication number
JP4060756B2
JP4060756B2 JP2003158404A JP2003158404A JP4060756B2 JP 4060756 B2 JP4060756 B2 JP 4060756B2 JP 2003158404 A JP2003158404 A JP 2003158404A JP 2003158404 A JP2003158404 A JP 2003158404A JP 4060756 B2 JP4060756 B2 JP 4060756B2
Authority
JP
Japan
Prior art keywords
charging
secondary battery
temperature
secondary batteries
charging mode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2003158404A
Other languages
Japanese (ja)
Other versions
JP2004364387A (en
Inventor
秀樹 宮本
靖 森
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
FDK Twicell Co Ltd
Original Assignee
Toshiba Battery Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Battery Co Ltd filed Critical Toshiba Battery Co Ltd
Priority to JP2003158404A priority Critical patent/JP4060756B2/en
Publication of JP2004364387A publication Critical patent/JP2004364387A/en
Application granted granted Critical
Publication of JP4060756B2 publication Critical patent/JP4060756B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Description

【０００１】
【発明の属する技術分野】
この発明は、例えばニッケルカドミウム電池や、ニッケル水素電池、リチウムイオン二次電池等の二次電池を充電する方法又は装置に係わり、特に複数の二次電池を並行して充電することが可能な充電方法及び充電装置とその充電制御プログラムに関する。
【０００２】
【従来の技術】
従来、複数の二次電池を並行して充電する装置として、定電流充電と定電圧充電とを組み合わせることで複数の二次電池を急速充電する装置が知られている。この充電装置は、例えば充電初期時に複数の二次電池を定電流電源に対し直列に接続して定電流充電を行う。そして、この定電流充電期間中に各二次電池の電圧をそれぞれ監視し、電圧が所定の電圧値に達した二次電池のみを切り離して当該二次電池を定電圧電源に接続して定電圧充電を行い、それ以外の二次電池に対しては引き続き定電流充電を行うように構成されている（例えば、特許文献１を参照。）。
ところが、上記従来の充電装置は定電流電源と定電圧電源の２種類の電源が必要となるため、装置のコストアップを招くという問題がある。
【０００３】
一方、最近では複数の二次電池に対し先ず直列充電を行い、充電電圧値が所定の切替条件に達した二次電池から順に並列充電に切り替えて充電を継続し、満充電の条件を満たした二次電池を充電終了として充電電源から切り離すようにした装置が提案されている。このような充電装置であれば充電電源は１種類で済むため、装置のコストダウンを図ることが可能となる。
【０００４】
【特許文献１】
特開平９−２６６６３８号公報。
【０００５】
【発明が解決しようとする課題】
しかしながら、このような装置は二次電池の電圧値のみをモニタして直列充電から並列充電への切替制御を行っている。このため、直列充電から並列充電への切替条件の設定値によっては直列充電期間中に二次電池の温度が上昇し過ぎて、二次電池の特性劣化を招くおそれがある。一方、上記不具合を解消するための切替条件の設定値を低い値に設定すると、直列充電から並列充電への切替タイミングが全般的に早くなるため、充電を完了するまでの時間が長くなると云う別の問題を生じる。
【０００６】
そこで、上記切替条件の設定にあたっては、上記相反する二つの問題を考慮して最適な値が選ばれる。しかし、複数の二次電池を並行して充電する装置では、各二次電池は充電中に隣接する他の電池から温度の影響を受ける。このため、各二次電池の温度上昇は、並行して充電を行う二次電池の数や各二次電池の初期条件により異なり、必ずしも最適な条件で直列充電から並列充電への切り替えが行われるとは限らない。
【０００７】
例えば、同時に充電を開始する複数の二次電池の中に残容量が比較的多い電池が含まれていると、この電池の温度上昇の影響により周辺の電池の温度が上昇し、この結果周辺の電池は充電電圧値が低いにもかかわらず温度が許容値を超えてしまうと云った不具合を生じる心配がある。
【０００８】
この発明は上記事情に着目してなされたもので、その目的とするところは、並行して充電される二次電池の数や初期条件にかかわらず、二次電池の温度上昇を抑えて常に安全な充電を可能にする二次電池の充電方法及び充電装置とその充電制御プログラムを提供することにある。
【０００９】
【課題を解決するための手段】
上記目的を達成するためにこの発明は、充電電源の出力をもとに複数の二次電池を充電する際に、先ず上記複数の二次電池を上記充電電源に対し直列接続して第１の充電モードによる充電を行い、この第１の充電モードによる充電が行われている期間に上記複数の二次電池の温度をそれぞれ監視する。そして、上記複数の二次電池のうち温度が予め設定された第１のしきい値を超えた二次電池が検出されたとき、当該温度上昇が検出された二次電池のみを上記充電電源に対し並列接続又は間欠接続させてこの二次電池に対し上記第１の充電モードよりも小電流の第２の充電モードによる充電を行わせ、他の二次電池に対しては上記第１の充電モードによる充電を継続させるようにしたものである。
【００１０】
したがってこの発明によれば、充電開始後、各二次電池に対しては先ず第１の充電モードによる充電、つまり直列接続による大電流充電が行われる。そして、この大電流充電期間中に二次電池の温度が第１のしきい値を超えると、以後この温度上昇した二次電池に対しては第２の充電モードによる充電、つまり並列接続による並列充電又は間欠接続によるパルス充電が行われる。このため、同時に充電を開始する二次電池の数や各二次電池の残容量等の初期条件が如何なる場合でも、二次電池の許容値以上の温度上昇を抑制して二次電池の特性劣化を確実に防止することができる。
【００１１】
また、温度上昇が検出された二次電池のみ第２の充電モードに切り替わるので、温度がまだしきい値に達していない二次電池については引き続き第１の充電モードによる充電を行うことができ、これによりすべての二次電池の充電所要時間を短縮することができる。
【００１２】
またこの発明は、上記第２の充電モードによる充電を行っている二次電池の温度を監視し、温度が上記第１のしきい値より低く設定された第２のしきい値未満に低下した二次電池が検出されたとき、当該温度低下が検出された二次電池の接続状態を直列接続に戻して、第１の充電モードによる充電を再度行うことも特徴とする。
【００１３】
このようにすると、並列接続又は間欠接続による小電流充電に移行した後、二次電池の温度が第２のしきい値未満に下がると、当該二次電池に対し再び直列接続による大電流充電が行われる。このため、並列接続又は間欠接続による小電流充電に移行した後、満充電までそのまま小電流充電を行う場合に比べ、二次電池の充電所要時間を短縮することが可能となる。すなわち、二次電池の温度上昇を抑制して電池の劣化を防止した上で、充電時間の短縮を図ることができる。
【００１４】
さらにこの発明は、上記第２の充電モードによる充電を行っている二次電池の温度変化特性を監視し、温度変化特性が予め設定した満充電に対応する条件を満たした二次電池が検出されたとき、当該二次電池を充電電源から切り離すことも特徴とする。
このようにすると、二次電池の温度監視のみにより満充電の判定を行うことが可能となり、これにより充電制御アルゴリズムを簡単化することができる。
【００１５】
【発明の実施の形態】
（第１の実施形態）
この発明の第１の実施形態は、複数の二次電池を並行して充電する際に、先ずこれらの二次電池に対し直列充電モード（第１の充電モード）による大電流充電を行う。そして、この直列充電モードによる充電期間に上記各二次電池のうち少なくとも１つの温度が第１のしきい値を超えたとき、上記各二次電池の接続状態を切り替え、以後満充電となるまで上記各二次電池に対し時分割のパルス充電モード（第２の充電モード）による小電流充電を行うようにしたものである。
【００１６】
図１は、この発明の第１の実施形態に係わる充電装置の構成を示すブロック図であり、１は充電電源を示している。この充電電源は、例えば商用電源出力を整流して充電に必要な直流電圧及び電流を出力する。
【００１７】
上記充電電源１の充電端子２ａ，２ｂには、接続切替回路３Ａを介して二次電池モジュール４が接続される。二次電池モジュール４は、例えば図示しない電池ホルダに複数（図では４個）の二次電池４１〜４４を着脱可能な状態に装着したもので、上記充電電源１から上記接続切替回路３Ａを介して供給される充電電圧及び電流により充電される。また二次電池モジュール４には、上記二次電池４１〜４４とそれぞれ対向する位置に温度検出素子５１〜５４が設けられている。これらの温度検出素子５１〜５４は例えばサーミスタからなり、充電期間中に上記各二次電池４１〜４４の温度に対応する電圧値をそれぞれ出力する。
【００１８】
また充電装置は、充電電流検出回路（Ｉ−ＤＥＴ）６と、充電電圧検出回路（Ｖ−ＤＥＴ）７と、温度検出回路（ＴＨ−ＤＥＴ）８と、充電制御回路９Ａと、スイッチ駆動回路１０とを備えている。
【００１９】
充電電流検出回路６は、充電期間中に上記二次電池４１〜４４に流れる充電電流値を検出してアナログ／ディジタル（Ａ／Ｄ）変換し、これにより得られる電流検出データＩＳを充電制御回路９Ａに供給する。充電電圧検出回路７は、上記各二次電池４１〜４４の充電電圧値Ｖ１〜Ｖ４をそれぞれ検出してＡ／Ｄ変換し、これにより得られる電圧検出データＶＳを充電制御回路９Ａに供給する。温度検出回路８は、上記各温度検出素子５１〜５４から出力される電圧値をそれぞれＡ／Ｄ変換し、これにより得られる温度検出データＴＨＳを充電制御回路９Ａに供給する。
【００２０】
ところで、上記接続切替回路３Ａは次のように構成される。図２はその構成を示す回路図である。すなわち、充電電源１の充電端子２ａから出力された充電電流は、４分岐されたのちそれぞれ逆流防止用ダイオードＤ１〜Ｄ４及びスイッチＳＷ１〜ＳＷ４を直列に介して二次電池４１〜４４に入力され、さらにスイッチＳＷ８〜ＳＷ１１をそれぞれ介して充電電源１の負端子２ｂへ帰還するように構成されている。以上の回路は並列充電回路を構成する。また、上記二次電池４１〜４４間にはそれぞれ、スイッチＳＷ５〜ＳＷ７及び短絡防止用ダイオードＤ５〜Ｄ７からなる直列回路が介挿されている。これらの直列回路は、直列充電回路を構成する。
【００２１】
上記各スイッチＳＷ１〜ＳＷ１１はいずれも半導体スイッチからなり、上記スイッチ駆動回路１０から出力されるスイッチ駆動信号に応じてオンオフ動作する。スイッチ駆動回路１０は、後述する充電制御回路９Ａから出力されるスイッチ制御信号ＳＷＣに応じて、上記各スイッチＳＷ１〜ＳＷ１１を駆動するためのスイッチ駆動信号を生成して各スイッチＳＷ１〜ＳＷ１１に与える。
【００２２】
一方、充電制御回路９Ａは例えばマイクロコンピュータからなり、次のように構成される。図３はその機能構成を示すブロック図である。すなわち、充電制御回路９Ａは、中央処理ユニット（ＣＰＵ：Central Processing Unit）９０と、入出力ポート（Ｉ／Ｏ）９１と、プログラムメモリ９２Ａと、データメモリ９３とを備えている。
【００２３】
Ｉ／Ｏ９１は、上記充電電流検出回路６、充電電圧検出回路７、温度検出回路８及びスイッチ駆動回路１０との間で、各検出データＩＳ，ＶＳ，ＴＨＳ及びスイッチ制御信号ＳＷＣの入出力を行う。またデータメモリ９３は、上記充電制御のために使用される各種しきい値データの保存と、充電制御の過程で生成される制御データの一時保存等を行うために使用される。
【００２４】
プログラムメモリ９２Ａには、この発明に係わる制御機能を実現するプログラムとして、第１の接続切替制御プログラム９２ａと、充電終了制御プログラム９２ｂが格納されている。
【００２５】
第１の接続切替制御プログラム９２ａは、充電に際し、先ず各二次電池４１〜４４を充電端子２ａ，２ｂ間に直列接続させるように接続切替回路３Ａの各スイッチを切替制御し、これにより各二次電池４１〜４４を直列充電モードにより充電させる。そして、この直列充電モードによる充電期間中に、温度検出回路８から各二次電池４１〜４４の温度検出データＴＨＳを取り込み、この温度検出データＴＨＳが第１のしきい値を超えたとき、各二次電池４１〜４４を充電端子２ａ，２ｂ間に時分割に間欠接続させるように接続切替回路３Ａの各スイッチを切替制御し、これにより各二次電池４１〜４４を時分割パルス充電モードにより充電させる。
【００２６】
充電終了制御プログラム９２ｂは、上記時分割パルス充電モードによる充電期間中に、温度検出回路８から各二次電池４１〜４４の温度検出データＴＨＳをそれぞれ取り込んでその温度上昇率を監視する。そして、温度上昇率がしきい値を超えたとき、当該二次電池を充電電源１から切り離すように接続切替回路３Ａのスイッチを切替制御する。
【００２７】
なお、プログラムメモリ９２Ａには異常対応プログラムも記憶されている。この異常対応プログラムは、過充電等の異常充電動作を検出するもので、充電制御中に上記電流検出回路６及び電圧検出回路７の検出データＩＳ，ＶＳを定期的に取り込んでその値を判定し、異常値が検出された場合に接続切替回路３Ａのすべてのスイッチをオフ状態に設定する。
【００２８】
次に、以上のように構成された充電装置の動作を、充電制御回路９Ａの制御手順に従い説明する。
図４はその制御手順と制御内容を示すフローチャート、図５は各二次電池４１〜４４に対する充電電流の供給タイミングを示す図であり、さらに図６は二次電池４１〜４４の充電電圧の変化特性イ及び温度変化特性ロの一例を示す図である。なお、図６中ハは測定パラメータの一つである室温（２５℃）示す。
【００２９】
充電対象の二次電池４１〜４４を電池ホルダに装着すると、充電制御回路９Ａは以下のように充電制御を開始する。すなわち、先ずステップ４ａにおいて直列充電のためのスイッチ制御信号ＳＷＣを生成してスイッチ駆動回路１０に与える。この結果、スイッチ駆動回路１０から、各二次電池４１〜４４を充電電源１に直列接続させるためのスイッチ駆動信号が出力される。このため、接続切替回路３Ａでは、スイッチＳＷ１，ＳＷ５，ＳＷ６，ＳＷ７，ＳＷ８がそれぞれオン状態となり、その他のスイッチＳＷ２，ＳＷ３，ＳＷ４，ＳＷ９，ＳＷ１０，ＳＷ１１はオフ状態となる。したがって、充電電源１から出力された充電電流は、スイッチＳＷ１−二次電池４１−スイッチＳＷ５−二次電池４２−スイッチＳＷ６−二次電池４３−スイッチＳＷ７−二次電池４４−スイッチＳＷ８の経路で流れ、各二次電池４１〜４４は直列充電される。
【００３０】
また、この直列充電が行われている期間に充電制御回路９Ａは、ステップ４ｂにより温度検出回路８から各二次電池４１〜４４の温度検出データＴＨＳをそれぞれ取り込み、上記取り込まれたデータＴＨＳにより表される検出温度をそれぞれ第１のしきい値とステップ４ｃで比較する。そして上記比較の結果、二次電池４１〜４４の検出温度がいずれも第１のしきい値を超えていなければ、引き続き上記ステップ４ｂによる温度の測定処理とステップ４ｃによる温度の比較処理を繰り返す。なお、上記第１のしきい値は二次電池の定格値により設定されるもので、例えば５０℃に設定される。
【００３１】
さて、上記直列充電の期間中に二次電池４１〜４４の温度が例えば図６のロに示すように上昇し、そのうち一個の電池の温度が第１のしきい値（５０℃）を超えたとする。そうすると、充電制御回路９Ａはステップ４ｃからステップ４ｄに移行し、ここで時分割パルス充電のためのスイッチ制御信号ＳＷＣを生成してスイッチ駆動回路１０に与える。この結果、スイッチ駆動回路１０から、各二次電池４１〜４４をそれぞれ一定の周期で一定時間ずつ時分割に充電電源１に接続させるためのスイッチ駆動信号が出力される。
【００３２】
このため接続切替回路３Ａでは、図５に示すように最初のパルス期間にスイッチＳＷ１，ＳＷ１１のみがオン状態となって二次電池４１に充電電流が供給され、次のパルス期間にはスイッチＳＷ２，ＳＷ１０のみがオン状態となって二次電池４２に充電電流が供給される。また、次のパルス期間にはスイッチＳＷ３，ＳＷ９のみがオン状態となって二次電池４３に充電電流が供給され、さらに次のパルス期間にはスイッチＳＷ４，ＳＷ８のみがオン状態となって二次電池４４に充電電流が供給される。以後、以上のように各二次電池４１〜４４に対し順次一定時間ずつ充電電流が供給され、この動作が一定の周期で繰り返される。なお、上記パルス期間は例えば５秒に設定され、またパルス期間の周期は２０秒に設定される。かくして、各二次電池４１〜４４は以上のような時分割パルス充電モードにより小電流充電される。
【００３３】
また、上記時分割パルス充電モードによる充電制御を行いながら、充電制御回路９Ａはステップ４ｅにより温度検出回路８から各二次電池４１〜４４の温度検出データＴＨＳをそれぞれ取り込む。そして、ステップ４ｆ及びステップ４ｇにより、所定時間連続して検出温度が上昇している二次電池の有無、すなわち温度上昇率がしきい値を超えた二次電池の有無を判定する。この判定の結果、いま二次電池４１の温度上昇率がしきい値を超えたとする。そうすると、充電制御回路９Ａは当該二次電池４１を充電電源１から切り離して充電電流の供給を停止し、残りの二次電池４２〜４４に対し時分割パルス充電モードによる充電制御を続ける。そして、他の二次電池４２〜４４についても、温度上昇率がしきい値以上となった時点で充電電源１から切り離して充電電流の供給を停止する。なお、上記温度上昇率のしきい値は、例えば０．８℃／１分に設定される。
【００３４】
以上述べたように第１の実施形態では、４個の二次電池４１〜４４を並行して充電する際に、先ず接続切替回路３Ａにより上記二次電池４１〜４４を充電電源１に対し直列に接続して、これにより直列充電モードによる充電を行う。そして、この直列充電モードによる充電期間中に上記各二次電池４１〜４４の温度を温度検出回路８により検出し、上記各二次電池４１〜４４のうち少なくとも１つの電池の温度が第１のしきい値（５０℃）を超えたとき、以後上記接続切替回路３Ａをスイッチング制御することにより各二次電池４１〜４４に対し時分割パルス充電モードによる充電を行う。そして、この時分割パルス充電モードによる充電期間中に上記各二次電池４１〜４４の温度上昇率をそれぞれ監視し、温度上昇率がしきい値を超えた二次電池を満充電と判定して充電電源１から切り離すようにしている。
【００３５】
したがって第１の実施形態によれば、二次電池４１〜４４の温度をそれぞれ監視しながら直列充電が行われ、温度が第１のしきい値を超えたとき時分割パルス充電に切り替えられる。このため、二次電池の数や二次電池の残容量が異なる場合でも、二次電池４１〜４４の温度が上昇し過ぎる前に確実に大電流充電から小電流充電に切り替えることができ、これにより二次電池４１〜４４の劣化を防ぐことができる。
【００３６】
また、二次電池４１〜４４の温度が第１のしきい値を超えるまでは直列充電が行われるので、温度の着目せず充電電圧のみにより充電モードを切り替える場合に比べ、充電に要する時間を短くすることができる。さらに、二次電池４１〜４４の温度上昇率を監視し、温度上昇率がしきい値を超えた時点で満充電と判定するようにしているので、温度のみに基づく簡単なアルゴリズムにより充電制御を行うことができる。
【００３７】
（第２の実施形態）
この発明の第２の実施形態は、複数の二次電池を並行して充電する際に、先ずこれらの二次電池に対し直列充電モード（第１の充電モード）による大電流充電を行い、この直列充電モードによる充電期間に上記各二次電池のうち少なくとも１つの温度が第１のしきい値を超えたとき、上記各二次電池の接続状態を切り替えて時分割のパルス充電モード（第２の充電モード）による小電流充電を行う。そして、上記時分割のパルス充電モードによる小電流充電期間に上記すべての二次電池の温度が第２のしきい値未満に低下したとき、上記各二次電池の充電モードを直列充電モード（第１の充電モード）に切り替えて再度大電流充電を行う。以後、満充電となるまで、二次電池の検出温度に基づいて、上記直列充電モードによる大電流充電と、時分割のパルス充電モードによる小電流充電とを繰り返すようにしたものである。
【００３８】
図７は、この発明の第２の実施形態における充電装置の要部である、充電制御回路の構成を示す機能ブロック図である。なお、同図において前記図３と同一部分には同一符号を付して詳しい説明は省略する。また、充電装置１の構成及び接続切替回路３Ａの回路構成については前記第１の実施形態と同一なので、ここでも図１及び図２を引用して説明する。
【００３９】
プログラムメモリ９２Ｂには、この発明に係わる制御機能を実現するプログラムとして、第１の切替制御プログラム９２ａ及び充電終了制御プログラム９２ｂに加え、第２の切替制御プログラム９２ｃが格納されている。
【００４０】
第２の切替制御プログラム９２ｃは、時分割パルス充電モードによる充電期間中に温度検出データＴＨＳを取り込んで各二次電池４１〜４４の温度を監視し、すべての二次電池４１〜４４の温度が第２のしきい値未満に低下したとき、時分割パルス充電モードから直列充電モードに戻す制御を行う。
【００４１】
次に、以上のように構成された充電装置の動作を、充電制御回路９Ｂの制御手順に従い説明する。
図８はその制御手順と制御内容を示すフローチャート、図９は各二次電池４１〜４４に対する充電電流の供給タイミングを示す図であり、さらに図１０は二次電池４１〜４４の充電電圧の変化特性イ及び温度変化特性ロを示す図である。なお、図１０中ハは測定パラメータの一つである室温（２５℃）示す。
【００４２】
充電対象の二次電池４１〜４４を電池ホルダに装着すると、充電制御回路９Ｂは先ずステップ８ａにおいて、接続切替回路３Ａに対し各二次電池４１〜４４を充電電源１に直列接続させるためのスイッチ制御を行う。この結果、スイッチＳＷ１，ＳＷ５，ＳＷ６，ＳＷ７，ＳＷ８のみがそれぞれオン状態となり、これにより各二次電池４１〜４４は直列充電される。
【００４３】
また、この直列充電が行われている期間に充電制御回路９Ｂは、ステップ８ｂにより温度検出回路８から各二次電池４１〜４４の温度検出データＴＨＳをそれぞれ取り込み、上記取り込まれたデータＴＨＳにより表される検出温度をそれぞれ第１のしきい値とステップ８ｃで比較する。そして上記比較の結果、二次電池４１〜４４の検出温度がいずれも第１のしきい値を超えていなければ、上記ステップ８ｂによる温度の測定処理とステップ８ｃによる温度の比較処理を繰り返す。なお、上記第１のしきい値は二次電池の定格値により設定されるもので、第１の実施形態と同様に例えば５０℃に設定される。
【００４４】
さて、上記直列充電の期間中に二次電池４１〜４４の温度が例えば図６のロに示すように上昇し、そのうち一個の電池の温度が第１のしきい値（５０℃）を超えたとする。そうすると、充電制御回路９Ｂはステップ８ｃからステップ８ｄに移行し、ここで接続切替回路３Ａに対し時分割パルス充電のためのスイッチ制御を行う。このため、各二次電池４１〜４４はそれぞれ一定の周期で一定時間ずつ時分割に充電電源１に接続されることになり、この結果各二次電池４１〜４４には例えば図９に示すように一定時間ずつ一定の周期で充電電流が供給される。なお、上記パルス期間及び繰り返し周期はそれぞれ、例えば５秒及び２０秒に設定される。かくして、各二次電池４１〜４４は以上のような時分割パルス充電モードにより小電流充電される。
【００４５】
また、上記時分割パルス充電モードによる充電制御を行いながら、充電制御回路９Ｂはステップ８ｅにより温度検出回路８から各二次電池４１〜４４の温度検出データＴＨＳをそれぞれ取り込む。そして、すべての二次電池４１〜４４の検出温度が第２のしきい値より低下したか否かをステップ８ｆにより判定すると共に、ステップ８ｇ及びステップ８ｈにより温度上昇率がしきい値以上の二次電池の有無を判定する。
【００４６】
そして、上記ステップ８ｆによる判定の結果、すべての二次電池４１〜４４の検出温度が第２のしきい値より低下すると、充電制御回路９Ｂは直列充電が可能な状態になったと判断し、ステップ８ａに戻る。そして、ここで接続切替回路３Ａに対し各二次電池４１〜４４を充電電源１に直列接続させるためのスイッチ制御を行う。この結果、各二次電池４１〜４４は再び直列充電される。なお、上記第２のしきい値は、例えば上記第１のしきい値より一定値だけ低い値に設定される。例えば、第１のしきい値が５０℃であれば、この値より２℃だけ低い４８℃に設定される。
【００４７】
以後、充電制御回路９Ｂは例えば図１０に示すように、二次電池４１〜４４の検出温度に基づいて、上記ステップ８ｂ乃至ステップ８ｆにより、直列充電モードから時分割パルス充電モードへの切り替えと、時分割パルス充電モードから直列充電モードへの切り替えとを繰り返す。
【００４８】
一方、上記時分割パルス充電モードによる充電期間中に、ある二次電池（例えば４４）の検出温度が所定時間連続して上昇したとする。すなわち、二次電池４４の温度上昇率がしきい値を超えたとする。そうすると、充電制御回路９Ｂは当該二次電池４４を充電電源１から切り離して充電電流の供給を停止し、残りの二次電池４１〜４３に対し時分割パルス充電モードによる充電制御を続ける。そして、他の二次電池４１〜４３についても、温度上昇率がしきい値以上となった時点で充電電源１から切り離して充電電流の供給を停止する。なお、上記温度上昇率のしきい値は、前記第１の実施形態と同様に例えば０．８℃／１分に設定される。
【００４９】
以上述べたように第２の実施形態では、４個の二次電池４１〜４４を並行して充電する際に、二次電池４１〜４４の温度に基づいて、直列充電モードから時分割パルス充電モードへの切り替えと、時分割パルス充電モードから直列充電モードへの切り替えとを繰り返すようにしている。
【００５０】
したがって、直列充電モードから時分割パルス充電モードへ切り替えたのちそのまま満充電まで充電を行う場合に比べ、温度上昇を抑制した上で、満充電になるまでに要する時間を短縮することができる。本発明者による測定によると、第１の実施形態で述べた直列充電モードから時分割パルス充電モードへ１回切り替える場合（図６に示す５３分）に比べ、第２の実施形態では図１０に示すように充電時間を４３分と１０分短縮できることが確認された。
【００５１】
また、直列充電モードから時分割パルス充電モードへの切り替えを１回だけ行う場合（繰り返しなしの場合）と、直列充電モードと時分割パルス充電モードとの間の切り替えを繰り返す場合（繰り返しありの場合）とで、二次電池の放電容量を比較したところ、図１１に示すように両者の間にほとんど差は認められず、第２の実施形態による充電方法の有効性が確認された。
【００５２】
（第３の実施形態）
この発明の第３の実施形態は、直列充電期間中の二次電池の温度が第１のしきい値を超えたときに、すべての二次電池を直列充電からパルス充電に切り替えずに、温度が第１のしきい値を超えた二次電池のみをパルス充電に切り替え、他の二次電池については直列充電を継続するようにしたものである。
【００５３】
図１２は、この発明の第３の実施形態に係わる充電装置に設けられる接続切替回路３Ｂの回路構成図である。
同図において、各二次電池４１〜４４にはそれぞれ逆流防止用ダイオードＤ１〜Ｄ４及びスイッチＳＷ２，ＳＷ８，ＳＷ５が直列に接続されており、スイッチＳＷ２，ＳＷ８，ＳＷ５がオンすることで上記各二次電池４１〜４４は充電端子２ａ，２ｂ間に直列接続する。
【００５４】
また、充電端子２ａと二次電池４２との間にはスイッチＳＷ１が設けられており、このスイッチＳＷ１がオンすることで充電経路から二次電池４１がバイパスされる。さらに、二次電池４１の負端子と二次電池４２の負端子との間、二次電池４２の負端子と二次電池４４の負端子との間、及び二次電池４３の負端子と二次電池４４の負端子との間にはそれぞれ、スイッチＳＷ３，ＳＷ９，ＳＷ６が設けられている。スイッチＳＷ３がオンすると、二次電池４２が充電経路からバイパスされる。スイッチＳＷ６がオンすると、二次電池４４が充電経路からバイパスされる。スイッチＳＷ９がオンすると、二次電池４３，４４が充電経路からバイパスされる。
【００５５】
さらに、充電端子２ａと二次電池４３の正端子との間、及び二次電池４３の正端子と二次電池４４の正端子との間にはそれぞれスイッチＳＷ７，ＳＷ４が設けられている。スイッチＳＷ７がオンすると、二次電池４１，４２が充電経路からバイパスされる。スイッチＳＷ４がオンすると、二次電池４３が充電経路からバイパスされる。
【００５６】
一方、充電制御回路は次のような手順により充電制御を実行する。図１３はその制御手順と制御内容を示すフローチャートである。なお、充電装置の全体構成及び充電制御回路の構成はそれぞれ前記図１及び図３と同一なので、以下図１及び図３を引用して説明を行う。
【００５７】
充電対象の二次電池４１〜４４を電池ホルダに装着すると、充電制御回路９Ａは先ずステップ１３ａにおいて直列充電のためのスイッチ制御信号ＳＷＣを生成してスイッチ駆動回路１０に与える。この結果、各二次電池４１〜４４を充電電源１に直列接続させるためのスイッチ駆動信号が、スイッチ駆動回路１０から出力される。このため、接続切替回路３Ｂでは、スイッチＳＷ２，ＳＷ８，ＳＷ５がそれぞれオン状態となり、その他のスイッチＳＷ１，ＳＷ３，ＳＷ４，ＳＷ６，ＳＷ７，ＳＷ９はいずれもオフ状態となる。したがって、充電電源１から出力された充電電流は、ダイオードＤ１−二次電池４１−スイッチＳＷ２−ダイオードＤ２−二次電池４２−スイッチＳＷ８−ダイオードＤ３−二次電池４３−スイッチＳＷ５−ダイオードＤ４−二次電池４４の経路で流れる。すなわち、各二次電池４１〜４４は直列充電される。
【００５８】
また、この直列充電が行われている期間に充電制御回路９Ａは、二次電池４１〜４４ごとに、その温度監視と、その監視結果に基づく充電モードの切替制御を実行する。すなわち、先ずステップ１３ｂで二次電池４１〜４４のうちの一つ（例えば４１）を選択し、ステップ１３ｃにより上記選択された二次電池４１の温度検出データＴＨＳを温度検出回路８から取り込む。そして、この取り込まれた温度検出データＴＨＳにより表される検出温度を第１のしきい値とステップ１３ｅで比較し、二次電池４１の検出温度が第１のしきい値を超えていなければ、ステップ１３ｆから上記ステップ１３ｂに戻る。
【００５９】
充電制御回路９Ａは、次に二次電池（例えば４２）を選択し、この二次電池４２について上記温度検出データを取り込むと共に、このデータにより表される検出温度と第１のしきい値との比較処理を実行する。以下同様に、残りの二次電池４３，４４についても、それぞれ温度検出データＴＨＳを取り込み、このデータにより表される検出温度と第１のしきい値との比較処理を実行する。
【００６０】
さて、以上の直列充電期間中に、例えば二次電池４２の温度が第１のしきい値（例えば５０℃）を超えたとする。そうすると充電制御回路９Ａは、ステップ１３ｅからステップ１３ｇに移行し、ここで上記二次電池４２に対する充電モードをパルス充電モードに切り替えるためのスイッチ制御信号ＳＷＣを生成してスイッチ駆動回路１０に与える。
【００６１】
この結果、以後接続切替回路３Ｂでは、スイッチＳＷ２，ＳＷ８，ＳＷ５がオンとなり、かつスイッチＳＷ１，ＳＷ３，ＳＷ４，ＳＷ６，ＳＷ７，ＳＷ９がオフとなる状態と、スイッチＳＷ３，ＳＷ８，ＳＷ５がオンとなり、かつスイッチＳＷ１，ＳＷ２，ＳＷ４，ＳＷ６，ＳＷ７，ＳＷ９がオフとなる状態とが、一定の周期で繰り返される。このため、二次電池４１，４３，４４に対しては引き続き直列充電モードによる大電流充電が行われるが、二次電池４２に対してはパルス充電モードにより間欠的に小電流充電が行われる。図１５（ａ）は、この二次電池４２に対してのみパルス充電が行われる場合の充電動作タイミングを示すものである。
【００６２】
また、上記パルス充電中の二次電池４２について、充電制御回路９Ａはステップ１３ｈにおいて満充電の判定を行う。この満充電の判定は、温度検出回路８から一定の時間間隔で二次電池４２の温度検出データＴＨＳを取り込んで温度上昇率を求め、この温度上昇率をしきい値と比較することにより行われる。この判定の結果、二次電池４２の温度上昇率がしきい値を超えると、充電制御回路９Ａはステップ１３ｉにより当該二次電池４２を充電電源１から切り離す。なお、上記温度上昇率のしきい値は、前記第１の実施形態と同様に例えば０．８℃／１分に設定される。
【００６３】
以下同様に、他の二次電池４１，４３，４４についても、検出温度が第１のしきい値を超えると、当該二次電池について充電モードを直列充電モードからパルス充電モードに切り替える処理がステップ１３ｇにより行われ、二次電池が満充電になるまでパルス充電モードによる充電が行われる。そして、すべての二次電池４１〜４４が満充電に達したことをステップ１３ｊにより検出すると、充電制御回路９Ａは充電制御を終了する。
【００６４】
以上述べたように第３の実施形態では、直列充電中の二次電池４１〜４４の温度をそれぞれ監視し、温度が第１のしきい値を超えた二次電池が検出されるごとに、当該二次電池について充電モードをパルス充電モードに切り替えて充電を行い、他の二次電池については直列充電を継続するようにしている。
【００６５】
したがって、個々の二次電池４１〜４４の温度上昇を個別に抑制しながら、温度が第１のしきい値に達していない二次電池についてはできる限り長時間にわたり直列充電を継続することが可能となり、これにより電池の温度劣化を防止した上で、全二次電池４１〜４４の充電所要時間を大幅に短縮することができる。
【００６６】
（第４の実施形態）
この発明の第４の実施形態は、直列充電期間中の二次電池の温度が第１のしきい値を超えたときに、この温度が第１のしきい値を超えた二次電池のみをパルス充電に切り替え、他の二次電池については直列充電を継続する。そして、上記パルス充電期間が行われている二次電池の温度が第２のしきい値未満に低下したとき、この二次電池の充電モードを再び直列充電モードに切り替えて再度直列充電を行う。以後、満充電になるまで、二次電池の検出温度に基づいて上記直列充電とパルス充電とを繰り返すようにしたものである。
【００６７】
この実施形態に係わる充電制御回路は次のような手順により充電制御を実行する。図１４はその制御手順と制御内容を示すフローチャートであり、前記図１３と同一部分には同一符号を付してある。なお、充電装置の全体構成及び充電制御回路の構成はそれぞれ前記図１及び図７と同一なので、以下図１及び図７を引用して説明を行う。
【００６８】
パルス充電に移行した二次電池（例えば４２）について、充電制御回路９Ｂはステップ１４ａにより温度検出回路８から当該二次電池４２の温度検出データＴＨＳを取り込む。そして、当該二次電池４２の検出温度が第２のしきい値より低下したか否かを判定する。そして、上記ステップ１４ａによる判定の結果、二次電池４２の検出温度が第２のしきい値より低下すると、充電制御回路９Ｂは当該二次電池４２が再び直列充電可能な状態になったと判断し、ステップ１３ａに戻る。
【００６９】
そして、充電制御回路９Ｂはこのステップ１３ａで接続切替回路３Ｂに対し二次電池４２を充電電源１に直列接続させるためのスイッチ制御を行う。この結果、二次電池４２は他の二次電池４１，４３，４４と共に充電電源１に対し再び直列接続され、以後直列充電される。図１５（ｂ）はこの場合の各二次電池４１〜４４の充電動作を示すタイミング図である。なお、上記第２のしきい値は、前記第２の実施形態と同様に上記第１のしきい値より一定値だけ低い値に設定される。例えば、第１のしきい値が５０℃であれば、この値より２℃だけ低い４８℃に設定される。
【００７０】
以後充電制御回路９Ｂは、例えば図１５（ｂ）に示すように、二次電池４１〜４４ごとにその検出温度に基づいて、上記ステップ１３ｂ乃至ステップ１３ｆによる直列充電モードからパルス充電モードへの切り替えと、ステップ１４ａ及びステップ１３ａによるパルス充電モードから直列充電モードへの切り替えとを繰り返す。
【００７１】
また充電制御回路９Ｂは、上記充電モードの切替制御を実行しながら、パルス充電モードによる充電が行われている二次電池について、ステップ１４ｂにより満充電になったか否かを判定する。この満充電の判定は、温度検出回路８により定期的に検出される二次電池の温度をもとに温度上昇率を算出し、この温度上昇率をしきい値と比較することによりなされる。
【００７２】
いま例えば、パルス充電モードにより充電が行われている二次電池４２の検出温度が所定時間連続して上昇したとする。すなわち、二次電池４４の温度上昇率がしきい値を超えたとする。そうすると、充電制御回路９Ｂはステップ１４ｃにより当該二次電池４２を充電電源１から切り離して充電電流の供給を停止する。なお、他の二次電池４１，４３，４４についても、パルス充電が行われている期間に温度上昇率がしきい値以上となった時点で、充電電源１から切り離して充電電流の供給を停止する。
【００７３】
以上述べたように第４の実施形態によれば、前記第３の実施形態と同様に直列充電モードからパルス充電モードへの切替制御が検出温度に応じて二次電池ごとに個別に行われる。しかも、一旦パルス充電モードに移行した二次電池であっても、温度が第２のしきい値以下に低下すれば再び直列充電モードに復帰して大電流による充電が行われる。したがって、個々の二次電池４１〜４４の温度上昇を個別に抑制しながら、温度が第１のしきい値に達していない二次電池、及び温度が一旦第１のしきい値に達してもその後第２のしきい値以下に低下した二次電池について、できる限り長時間にわたり直列充電を継続することが可能となる。このため、二次電池４１〜４４の温度劣化を防止した上で、全二次電池４１〜４４の充電所要時間をさらに短縮することができる。
【００７４】
（その他の実施形態）
前記各実施形態では、パルス充電期間中に温度上昇率がしきい値を超えた二次電池を満充電と判断して充電を停止するようにした。しかしそれに限らず、パルス充電期間中に各二次電池の温度を定期的にサンプリングしてその変化を監視し、この監視データをもとに温度が一旦低下したのち上昇に転じてしきい値に達したことをもって満充電と判定するようにしてもよい。
【００７５】
また前記各実施形態では、第１及び第２のしきい値、温度上昇率のしきい値を固定値とした。しかし、室温や、二次電池の種類又は銘柄等に応じて適応的に可変設定するようにしてもよい。これは、温度検出素子により充電開始直前の温度を室温として検出することで、また装着された二次電池の種類又は銘柄を光学的に読み取ることで実現できる。
【００７６】
さらに、電池ホルダの端子に対する二次電池の接触不良等を監視して、電池の未接続や電池異常を検出する手段を設ける。そして、この検出手段により電池の未接続や電池異常が検出された場合に、当該二次電池を充電電源から切り離すようにしてもよい。
【００７７】
さらに第３の実施形態では、直列充電期間中に４個の二次電池４１〜４４のうち温度が第１のしきい値を超えた二次電池が検出されたときに、当該二次電池のみを直列充電からパルス充電に切り替えるようにした。しかし、それに限らず、温度が第１のしきい値を超えた二次電池と、当該電池に隣接する二次電池について充電モードをパルス充電モードに切り替えるようにしてもよい。
【００７８】
さらに第２の実施形態では、時分割パルス充電期間中にすべての二次電池４１〜４４の温度が第２のしきい値未満に低下した場合に、充電モードを直列充電モードに戻すようにした。しかしこれに限らず、第４の実施形態のように温度が第２のしきい値未満に低下した二次電池が検出されるごとに当該二次電池に対する充電モードを直列充電モードに切り替えるようにしてもよい。
【００７９】
さらに各実施形態では、小電流充電を行うための第２の充電モードとして時分割パルス充電モード或いはパルス充電モードを使用した場合を例にとって説明したが、第２の充電モードとしては並列充電モードを使用することも可能である。その他、並行充電する二次電池の本数や二次電池の種類、接続切替回路及び充電制御回路の回路構成、充電制御手順とその制御内容等についても、この発明の要旨を逸脱しない範囲で種々変形して実施できる。
【００８０】
要するに、この発明は上記各実施形態そのままに限定されるものではなく、実施段階ではその要旨を逸脱しない範囲で構成要素を変形して具体化できる。また、上記実施形態に開示されている複数の構成要素の適宜な組み合せにより種々の発明を形成できる。例えば、実施形態に示される全構成要素から幾つかの構成要素を削除してもよい。更に、異なる実施形態に亘る構成要素を適宜組み合せてもよい。
【００８１】
【発明の効果】
以上詳述したようにこの発明では、先ず上記複数の二次電池を上記充電電源に対し直列接続して第１の充電モードによる大電流充電を行い、この第１の充電モードによる充電が行われている期間に上記複数の二次電池の温度をそれぞれ監視し、上記複数の二次電池のうち温度が予め設定された第１のしきい値を超えた二次電池が検出されたとき、当該温度上昇が検出された二次電池のみを上記充電電源に対し並列接続又は間欠接続させてこの二次電池に対し上記第１の充電モードよりも小電流の第２の充電モードによる充電を行わせ、他の二次電池に対しては上記第１の充電モードによる充電を継続させるようにしている。
したがってこの発明によれば、並行して充電される二次電池の数や初期条件にかかわらず、各二次電池の温度上昇を抑えて常に安全な充電を行うことができる二次電池の充電方法及び充電装置とその充電制御プログラムを提供することができる。
【図面の簡単な説明】
【図１】 この発明の第１の実施形態に係わる充電装置の構成を示すブロック図。
【図２】 図１に示した充電装置に設けられる接続切替回路の構成を示す回路図。
【図３】 図１に示した充電装置に設けられる充電制御回路の機能構成を示すブロック図。
【図４】 図３に示した充電制御回路による充電制御手順と制御内容を示すフローチャート。
【図５】 図４に示すフローチャートに従い行われる充電動作のタイミングを示す図。
【図６】 図４に示すフローチャートに従い行われる充電動作の充電電圧及び温度特性の変化特性を示す図。
【図７】 この発明の第２の実施形態に係わる充電装置に設けられる充電制御回路の機能構成を示す回路図。
【図８】 図７に示した充電制御回路による充電制御手順と制御内容を示すフローチャート。
【図９】 図８に示すフローチャートに従い行われる充電動作のタイミングを示す図。
【図１０】 図８に示すフローチャートに従い行われる充電動作の充電電圧及び温度特性の変化特性を示す図。
【図１１】 充電モードの切り替えを繰り返さない場合と繰り返す場合の二次電池の放電容量を比較して示す図。
【図１２】 この発明の第３の実施形態に係わる充電装置に設けられる接続切替回路の構成を示す回路図。
【図１３】 図１２に示す接続切替回路を使用して充電を行う場合の制御手順と制御内容を示すフローチャート。
【図１４】 この発明の第４の実施形態における充電制御手順と制御内容を示すフローチャート。
【図１５】 図１３及び図１４に示すフローチャートに従い行われる充電動作のタイミングを示す図。
【符号の説明】
１…充電電源、２ａ，２ｂ…充電端子、３Ａ，３Ｂ…接続切替回路、４…二次電池モジュール、６…電流検出回路（Ｉ−ＤＥＴ）、７…電圧検出回路（Ｖ−ＤＥＴ）、８…温度検出回路（ＴＨ−ＤＥＴ）、９Ａ，９Ｂ…充電制御回路、１０…スイッチ駆動回路、４１〜４４…二次電池、５１〜５４…温度検出素子、９０…ＣＰＵ、９１…Ｉ／Ｏ、９２Ａ，９２Ｂ…プログラムメモリ、９２ａ…第１の接続切替制御プログラム、９２ｂ…充電終了制御プログラム、９２ｃ…第２の接続切替制御プログラム、９３…データメモリ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method or apparatus for charging a secondary battery such as a nickel cadmium battery, a nickel metal hydride battery, or a lithium ion secondary battery, and more particularly, charging capable of charging a plurality of secondary batteries in parallel. The present invention relates to a method, a charging device, and a charging control program thereof.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a device that charges a plurality of secondary batteries in parallel, a device that rapidly charges a plurality of secondary batteries by combining constant current charging and constant voltage charging is known. In this charging device, for example, a plurality of secondary batteries are connected in series with a constant current power source at the initial stage of charging to perform constant current charging. During this constant current charging period, the voltage of each secondary battery is monitored, only the secondary battery whose voltage has reached a predetermined voltage value is disconnected, and the secondary battery is connected to a constant voltage power source to Charging is performed, and constant current charging is continuously performed on the other secondary batteries (see, for example, Patent Document 1).
However, since the conventional charging device requires two types of power sources, a constant current power source and a constant voltage power source, there is a problem that the cost of the device is increased.
[0003]
On the other hand, recently, a plurality of secondary batteries are first charged in series, and the secondary battery whose charging voltage value has reached a predetermined switching condition is switched to parallel charging in order from the secondary battery to satisfy the full charging condition. An apparatus has been proposed in which a secondary battery is disconnected from a charging power source when charging is completed. With such a charging device, only one type of charging power source is required, so that the cost of the device can be reduced.
[0004]
[Patent Document 1]
JP-A-9-266638.
[0005]
[Problems to be solved by the invention]
However, such a device monitors only the voltage value of the secondary battery and performs switching control from serial charging to parallel charging. For this reason, depending on the set value of the switching condition from series charging to parallel charging, the temperature of the secondary battery may rise excessively during the series charging period, which may cause deterioration of the characteristics of the secondary battery. On the other hand, if the setting value of the switching condition for solving the above problem is set to a low value, the switching timing from the series charging to the parallel charging is generally accelerated, so that it takes a long time to complete the charging. Cause problems.
[0006]
Therefore, in setting the switching condition, an optimal value is selected in consideration of the two conflicting problems. However, in a device that charges a plurality of secondary batteries in parallel, each secondary battery is affected by temperature from other adjacent batteries during charging. For this reason, the temperature rise of each secondary battery differs depending on the number of secondary batteries that are charged in parallel and the initial conditions of each secondary battery, and switching from serial charging to parallel charging is always performed under optimum conditions. Not necessarily.
[0007]
For example, if a battery with a relatively large remaining capacity is included in a plurality of secondary batteries that start charging at the same time, the temperature of the surrounding battery rises due to the effect of the temperature rise of the battery. There is a concern that the battery has a problem that the temperature exceeds the allowable value even though the charging voltage value is low.
[0008]
The present invention has been made by paying attention to the above circumstances, and the object of the present invention is to keep the temperature rise of the secondary battery constantly safe regardless of the number of secondary batteries charged in parallel and the initial conditions. The present invention provides a charging method and a charging device for a secondary battery, and a charging control program for the secondary battery, which enable easy charging.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, when charging a plurality of secondary batteries based on the output of a charging power source, the plurality of secondary batteries are first connected in series to the charging power source. Charging is performed in the charging mode, and the temperatures of the plurality of secondary batteries are monitored during the period in which charging is performed in the first charging mode. And when a secondary battery whose temperature exceeds a preset first threshold value among the plurality of secondary batteries is detected, Only the secondary battery in which the temperature rise is detected is connected in parallel or intermittently to the charging power source, and the secondary battery is charged in the second charging mode with a smaller current than the first charging mode. The other secondary batteries continue to be charged in the first charging mode. It is what I did.
[0010]
Therefore, according to the present invention, after starting charging, each secondary battery is first charged in the first charging mode, that is, charged with a large current by serial connection. When the temperature of the secondary battery exceeds the first threshold value during the large current charging period, the secondary battery whose temperature has risen thereafter is charged in the second charging mode, that is, in parallel by parallel connection. Pulse charging by charging or intermittent connection is performed. Therefore, regardless of the initial conditions such as the number of secondary batteries that start charging at the same time and the remaining capacity of each secondary battery, the temperature rise above the allowable value of the secondary battery is suppressed and the characteristics of the secondary battery are deteriorated. Can be reliably prevented.
[0011]
Also, Since only the secondary battery in which the temperature rise is detected is switched to the second charging mode, the secondary battery whose temperature has not yet reached the threshold value can be continuously charged in the first charging mode. The time required for charging all the secondary batteries can be shortened.
[0012]
The present invention also monitors the temperature of the secondary battery that is charging in the second charging mode, and the temperature has dropped below a second threshold value set lower than the first threshold value. When the secondary battery is detected, the connection state of the secondary battery in which the temperature drop is detected is returned to the serial connection, and charging in the first charging mode is performed again.
[0013]
In this way, after the transition to the small current charging by the parallel connection or the intermittent connection, when the temperature of the secondary battery falls below the second threshold value, the secondary battery is again charged with the large current by the serial connection. Done. For this reason, after shifting to the small current charge by parallel connection or intermittent connection, it becomes possible to shorten the charge required time of a secondary battery compared with the case where small current charge is performed as it is until full charge. That is, the charging time can be shortened while suppressing the temperature rise of the secondary battery to prevent the battery from deteriorating.
[0014]
Further, the present invention monitors the temperature change characteristic of the secondary battery that is charged in the second charge mode, and detects a secondary battery that satisfies the condition corresponding to the preset full charge. The secondary battery is also disconnected from the charging power source.
If it does in this way, it will become possible to determine full charge only by monitoring the temperature of a secondary battery, and, thereby, a charge control algorithm can be simplified.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
In the first embodiment of the present invention, when charging a plurality of secondary batteries in parallel, first, these secondary batteries are charged with a large current in a series charging mode (first charging mode). Then, when the temperature of at least one of the secondary batteries exceeds the first threshold during the charging period in the series charging mode, the connection state of the secondary batteries is switched until the battery is fully charged thereafter. Each of the secondary batteries is subjected to small current charging in a time-sharing pulse charging mode (second charging mode).
[0016]
FIG. 1 is a block diagram showing the configuration of a charging apparatus according to the first embodiment of the present invention. Reference numeral 1 denotes a charging power source. For example, this charging power supply rectifies the commercial power supply output and outputs a DC voltage and current necessary for charging.
[0017]
The secondary battery module 4 is connected to the charging terminals 2a and 2b of the charging power source 1 through a connection switching circuit 3A. The secondary battery module 4 is a module in which a plurality of (four in the figure) secondary batteries 41 to 44 are detachably attached to a battery holder (not shown), for example, from the charging power source 1 via the connection switching circuit 3A. It is charged by the charging voltage and current supplied. The secondary battery module 4 is provided with temperature detection elements 51 to 54 at positions facing the secondary batteries 41 to 44, respectively. These temperature detection elements 51 to 54 are, for example, thermistors, and output voltage values corresponding to the temperatures of the secondary batteries 41 to 44, respectively, during the charging period.
[0018]
The charging device includes a charging current detection circuit (I-DET) 6, a charging voltage detection circuit (V-DET) 7, a temperature detection circuit (TH-DET) 8, a charging control circuit 9A, and a switch drive circuit 10. And.
[0019]
The charging current detection circuit 6 detects the charging current value flowing through the secondary batteries 41 to 44 during the charging period and performs analog / digital (A / D) conversion, and the current detection data IS obtained thereby is a charging control circuit. Supply to 9A. The charging voltage detection circuit 7 detects the charging voltage values V1 to V4 of the respective secondary batteries 41 to 44, performs A / D conversion, and supplies voltage detection data VS obtained thereby to the charging control circuit 9A. The temperature detection circuit 8 A / D converts the voltage values output from the temperature detection elements 51 to 54, and supplies the temperature detection data THS obtained thereby to the charge control circuit 9A.
[0020]
By the way, the connection switching circuit 3A is configured as follows. FIG. 2 is a circuit diagram showing the configuration. That is, the charging current output from the charging terminal 2a of the charging power source 1 is branched into four and then input to the secondary batteries 41 to 44 via the backflow prevention diodes D1 to D4 and the switches SW1 to SW4 in series. Furthermore, it is configured to return to the negative terminal 2b of the charging power source 1 through the switches SW8 to SW11. The above circuit constitutes a parallel charging circuit. Further, series circuits including switches SW5 to SW7 and short-circuit preventing diodes D5 to D7 are interposed between the secondary batteries 41 to 44, respectively. These series circuits constitute a series charging circuit.
[0021]
Each of the switches SW1 to SW11 is composed of a semiconductor switch, and is turned on / off according to a switch drive signal output from the switch drive circuit 10. The switch drive circuit 10 generates a switch drive signal for driving the switches SW1 to SW11 according to a switch control signal SWC output from a charge control circuit 9A described later, and supplies the switch drive signal to the switches SW1 to SW11.
[0022]
On the other hand, the charging control circuit 9A is composed of, for example, a microcomputer and is configured as follows. FIG. 3 is a block diagram showing the functional configuration. That is, the charging control circuit 9A includes a central processing unit (CPU) 90, an input / output port (I / O) 91, a program memory 92A, and a data memory 93.
[0023]
The I / O 91 inputs / outputs the detection data IS, VS, THS and the switch control signal SWC with the charging current detection circuit 6, the charging voltage detection circuit 7, the temperature detection circuit 8, and the switch drive circuit 10. . The data memory 93 is used for storing various threshold data used for the charge control and temporarily storing control data generated in the charge control process.
[0024]
The program memory 92A stores a first connection switching control program 92a and a charge termination control program 92b as programs for realizing the control function according to the present invention.
[0025]
When charging, the first connection switching control program 92a first controls each switch of the connection switching circuit 3A so that the secondary batteries 41 to 44 are connected in series between the charging terminals 2a and 2b. The secondary batteries 41 to 44 are charged in the series charging mode. Then, during the charging period in the serial charging mode, the temperature detection data THS of the secondary batteries 41 to 44 is taken from the temperature detection circuit 8, and when the temperature detection data THS exceeds the first threshold value, Each switch of the connection switching circuit 3A is switched and controlled so that the secondary batteries 41 to 44 are intermittently connected between the charging terminals 2a and 2b in a time-division manner, whereby each of the secondary batteries 41 to 44 is controlled in a time-division pulse charging mode. Let it charge.
[0026]
The charge termination control program 92b takes in the temperature detection data THS of each of the secondary batteries 41 to 44 from the temperature detection circuit 8 and monitors the temperature increase rate during the charging period in the time division pulse charging mode. Then, when the rate of temperature rise exceeds the threshold value, the switch of the connection switching circuit 3A is controlled to be disconnected so that the secondary battery is disconnected from the charging power source 1.
[0027]
The program memory 92A also stores an abnormality handling program. This abnormality handling program detects an abnormal charging operation such as overcharging, and periodically reads the detection data IS and VS of the current detection circuit 6 and the voltage detection circuit 7 during charge control and determines their values. When an abnormal value is detected, all the switches of the connection switching circuit 3A are set to an off state.
[0028]
Next, the operation of the charging apparatus configured as described above will be described according to the control procedure of the charging control circuit 9A.
FIG. 4 is a flowchart showing the control procedure and control contents, FIG. 5 is a diagram showing the charging current supply timing to each of the secondary batteries 41 to 44, and FIG. 6 is a change in the charging voltage of the secondary batteries 41 to 44. It is a figure which shows an example of characteristic A and temperature change characteristic B. In FIG. 6, C indicates room temperature (25 ° C.), which is one of the measurement parameters.
[0029]
When the secondary batteries 41 to 44 to be charged are attached to the battery holder, the charging control circuit 9A starts charging control as follows. That is, first, in step 4a, a switch control signal SWC for series charging is generated and supplied to the switch driving circuit 10. As a result, the switch drive circuit 10 outputs a switch drive signal for connecting the secondary batteries 41 to 44 to the charging power source 1 in series. For this reason, in the connection switching circuit 3A, the switches SW1, SW5, SW6, SW7, and SW8 are turned on, and the other switches SW2, SW3, SW4, SW9, SW10, and SW11 are turned off. Therefore, the charging current output from the charging power source 1 is a path of switch SW1-secondary battery 41-switch SW5-secondary battery 42-switch SW6-secondary battery 43-switch SW7-secondary battery 44-switch SW8. The secondary batteries 41 to 44 are charged in series.
[0030]
Further, during the period in which the series charging is performed, the charging control circuit 9A takes in the temperature detection data THS of each of the secondary batteries 41 to 44 from the temperature detection circuit 8 in step 4b, and displays the data THS by the fetched data THS. Each detected temperature is compared with the first threshold value in step 4c. As a result of the comparison, if none of the detected temperatures of the secondary batteries 41 to 44 exceed the first threshold value, the temperature measurement process in step 4b and the temperature comparison process in step 4c are repeated. The first threshold value is set according to the rated value of the secondary battery, and is set to 50 ° C., for example.
[0031]
Now, during the series charging period, the temperature of the secondary batteries 41 to 44 rises as shown in FIG. 6B, for example, and the temperature of one of the batteries exceeds the first threshold (50 ° C.). To do. Then, the charging control circuit 9A shifts from step 4c to step 4d, where a switch control signal SWC for time division pulse charging is generated and supplied to the switch driving circuit 10. As a result, the switch drive circuit 10 outputs a switch drive signal for connecting each of the secondary batteries 41 to 44 to the charging power source 1 in a time-division manner with a fixed period.
[0032]
For this reason, in the connection switching circuit 3A, as shown in FIG. 5, only the switches SW1 and SW11 are turned on in the first pulse period and the charging current is supplied to the secondary battery 41, and the switches SW2 and SW2 are supplied in the next pulse period. Only the SW 10 is turned on, and the charging current is supplied to the secondary battery 42. In the next pulse period, only the switches SW3 and SW9 are turned on to supply the charging current to the secondary battery 43. In the next pulse period, only the switches SW4 and SW8 are turned on and the secondary battery 43 is turned on. A charging current is supplied to the battery 44. Thereafter, as described above, the charging current is sequentially supplied to each of the secondary batteries 41 to 44 for a certain period of time, and this operation is repeated at a certain period. The pulse period is set to 5 seconds, for example, and the period of the pulse period is set to 20 seconds. Thus, each of the secondary batteries 41 to 44 is charged with a small current in the time division pulse charging mode as described above.
[0033]
Further, while performing the charge control in the time-division pulse charge mode, the charge control circuit 9A takes in the temperature detection data THS of each of the secondary batteries 41 to 44 from the temperature detection circuit 8 in step 4e. In step 4f and step 4g, the presence / absence of a secondary battery whose detected temperature continuously increases for a predetermined time, that is, the presence / absence of a secondary battery whose temperature increase rate exceeds a threshold value is determined. As a result of this determination, it is assumed that the temperature increase rate of the secondary battery 41 has exceeded the threshold value. Then, the charging control circuit 9A disconnects the secondary battery 41 from the charging power supply 1 and stops the supply of the charging current, and continues the charging control in the time division pulse charging mode for the remaining secondary batteries 42 to 44. And about the other secondary batteries 42-44, when the rate of temperature increase becomes more than a threshold value, it disconnects from the charging power supply 1, and stops supply of charging current. The threshold value of the temperature increase rate is set to 0.8 ° C./1 minute, for example.
[0034]
As described above, in the first embodiment, when the four secondary batteries 41 to 44 are charged in parallel, the secondary batteries 41 to 44 are first connected in series with the charging power source 1 by the connection switching circuit 3A. Thus, charging is performed in the serial charging mode. Then, the temperature of each of the secondary batteries 41 to 44 is detected by the temperature detection circuit 8 during the charging period in the series charging mode, and the temperature of at least one of the secondary batteries 41 to 44 is the first temperature. When the threshold value (50 ° C.) is exceeded, the secondary battery 41 to 44 is charged in the time division pulse charging mode by switching the connection switching circuit 3A thereafter. Then, during the charging period in this time-division pulse charging mode, the temperature increase rate of each of the secondary batteries 41 to 44 is monitored, and the secondary battery whose temperature increase rate exceeds the threshold is determined to be fully charged. The charging power source 1 is disconnected.
[0035]
Therefore, according to the first embodiment, serial charging is performed while monitoring the temperatures of the secondary batteries 41 to 44, respectively, and switching to time division pulse charging is performed when the temperature exceeds the first threshold value. For this reason, even when the number of secondary batteries and the remaining capacity of the secondary batteries are different, the secondary batteries 41 to 44 can be reliably switched from large current charging to small current charging before the temperature of the secondary batteries 41 to 44 increases excessively. Therefore, the deterioration of the secondary batteries 41 to 44 can be prevented.
[0036]
In addition, since the series charging is performed until the temperature of the secondary batteries 41 to 44 exceeds the first threshold value, the time required for charging is shorter than when the charging mode is switched only by the charging voltage without paying attention to the temperature. Can be shortened. Furthermore, since the temperature rise rate of the secondary batteries 41 to 44 is monitored and it is determined that the battery is fully charged when the temperature rise rate exceeds the threshold value, the charging control is performed by a simple algorithm based only on the temperature. It can be carried out.
[0037]
(Second Embodiment)
In the second embodiment of the present invention, when charging a plurality of secondary batteries in parallel, first, these secondary batteries are charged with a large current in a series charging mode (first charging mode). When the temperature of at least one of the secondary batteries exceeds the first threshold during the charging period in the series charging mode, the connection state of the secondary batteries is switched to perform time-division pulse charging mode (second Charge mode). Then, when the temperature of all the secondary batteries decreases below the second threshold during the small current charging period in the time-sharing pulse charging mode, the charging mode of each of the secondary batteries is changed to the serial charging mode (first charging mode). (1 charging mode) and charging with a large current again. Thereafter, based on the detected temperature of the secondary battery, the large current charging in the series charging mode and the small current charging in the time-division pulse charging mode are repeated until the battery is fully charged.
[0038]
FIG. 7 is a functional block diagram showing a configuration of a charging control circuit, which is a main part of the charging device according to the second embodiment of the present invention. In the figure, the same parts as those in FIG. Further, since the configuration of the charging device 1 and the circuit configuration of the connection switching circuit 3A are the same as those of the first embodiment, description will be given here with reference to FIGS.
[0039]
The program memory 92B stores a second switching control program 92c in addition to the first switching control program 92a and the charging end control program 92b as programs for realizing the control function according to the present invention.
[0040]
The second switching control program 92c captures the temperature detection data THS during the charging period in the time division pulse charging mode and monitors the temperatures of the secondary batteries 41 to 44, and the temperatures of all the secondary batteries 41 to 44 are changed. When it falls below the second threshold, control is performed to return from the time division pulse charging mode to the series charging mode.
[0041]
Next, the operation of the charging apparatus configured as described above will be described according to the control procedure of the charging control circuit 9B.
FIG. 8 is a flowchart showing the control procedure and control contents, FIG. 9 is a diagram showing the supply timing of charging current to each of the secondary batteries 41 to 44, and FIG. 10 is a change in the charging voltage of the secondary batteries 41 to 44. It is a figure which shows the characteristic a and temperature change characteristic b. In FIG. 10, C indicates room temperature (25 ° C.), which is one of the measurement parameters.
[0042]
When the secondary batteries 41 to 44 to be charged are attached to the battery holder, the charging control circuit 9B first switches in step 8a to connect the secondary batteries 41 to 44 to the charging power source 1 in series with the connection switching circuit 3A. Take control. As a result, only the switches SW1, SW5, SW6, SW7, and SW8 are turned on, whereby the secondary batteries 41 to 44 are charged in series.
[0043]
Further, during the period in which the series charging is performed, the charging control circuit 9B takes in the temperature detection data THS of each of the secondary batteries 41 to 44 from the temperature detection circuit 8 in step 8b, and displays the data THS by the fetched data THS. Each detected temperature is compared with the first threshold value in step 8c. If the detected temperatures of the secondary batteries 41 to 44 do not exceed the first threshold value as a result of the comparison, the temperature measurement process in step 8b and the temperature comparison process in step 8c are repeated. The first threshold value is set according to the rated value of the secondary battery, and is set to, for example, 50 ° C. as in the first embodiment.
[0044]
Now, during the series charging period, the temperature of the secondary batteries 41 to 44 rises as shown in FIG. 6B, for example, and the temperature of one of the batteries exceeds the first threshold (50 ° C.). To do. Then, the charging control circuit 9B shifts from step 8c to step 8d, where switch control for time division pulse charging is performed on the connection switching circuit 3A. For this reason, the secondary batteries 41 to 44 are connected to the charging power source 1 in a time-sharing manner with a fixed period and at a constant time. As a result, each of the secondary batteries 41 to 44 has, for example, as shown in FIG. The charging current is supplied at regular intervals for a certain period of time. The pulse period and the repetition period are set to 5 seconds and 20 seconds, for example. Thus, each of the secondary batteries 41 to 44 is charged with a small current in the time division pulse charging mode as described above.
[0045]
Further, while performing the charge control in the time-division pulse charge mode, the charge control circuit 9B takes in the temperature detection data THS of each of the secondary batteries 41 to 44 from the temperature detection circuit 8 in step 8e. Then, it is determined in step 8f whether or not the detected temperatures of all the secondary batteries 41 to 44 are lower than the second threshold value, and in step 8g and step 8h, the temperature increase rate is greater than or equal to the threshold value. The presence or absence of a secondary battery is determined.
[0046]
Then, as a result of the determination in step 8f, when the detected temperature of all the secondary batteries 41 to 44 is lower than the second threshold value, it is determined that the charging control circuit 9B is in a state in which series charging is possible, and step Return to 8a. And the switch control for connecting each secondary battery 41-44 to the charging power supply 1 in series with respect to the connection switching circuit 3A here is performed. As a result, the secondary batteries 41 to 44 are serially charged again. Note that the second threshold value is set to a value lower than the first threshold value by a certain value, for example. For example, if the first threshold is 50 ° C., it is set to 48 ° C., which is 2 ° C. lower than this value.
[0047]
Thereafter, for example, as shown in FIG. 10, the charging control circuit 9B switches from the serial charging mode to the time-division pulse charging mode by the above steps 8b to 8f based on the detected temperature of the secondary batteries 41 to 44, The switching from the time division pulse charging mode to the series charging mode is repeated.
[0048]
On the other hand, it is assumed that the detected temperature of a certain secondary battery (for example, 44) rises continuously for a predetermined time during the charging period in the time division pulse charging mode. That is, it is assumed that the temperature increase rate of the secondary battery 44 exceeds the threshold value. Then, the charging control circuit 9B disconnects the secondary battery 44 from the charging power source 1 and stops the supply of the charging current, and continues the charging control in the time division pulse charging mode for the remaining secondary batteries 41 to 43. And also about the other secondary batteries 41-43, when the rate of temperature increase becomes more than a threshold value, it cuts off from the charging power supply 1, and stops supply of charging current. Note that the threshold value of the temperature increase rate is set to 0.8 ° C./1 minute, for example, as in the first embodiment.
[0049]
As described above, in the second embodiment, when the four secondary batteries 41 to 44 are charged in parallel, the time-division pulse charging is performed from the series charge mode based on the temperature of the secondary batteries 41 to 44. Switching to the mode and switching from the time division pulse charging mode to the series charging mode are repeated.
[0050]
Therefore, it is possible to reduce the time required to reach full charge while suppressing the temperature rise as compared with the case of charging from full charge to the time division pulse charge mode after switching from the serial charge mode. According to the measurement by the present inventor, the second embodiment shown in FIG. 10 is different from the case of switching from the series charge mode to the time-division pulse charge mode once (53 minutes shown in FIG. 6) described in the first embodiment. As shown, it was confirmed that the charging time could be shortened to 43 minutes and 10 minutes.
[0051]
Also, when switching from the series charge mode to the time-division pulse charge mode only once (without repetition), and when switching between the series charge mode and the time-division pulse charge mode is repeated (with repetition) ) And the discharge capacities of the secondary batteries were compared, as shown in FIG. 11, almost no difference was observed between them, confirming the effectiveness of the charging method according to the second embodiment.
[0052]
(Third embodiment)
In the third embodiment of the present invention, when the temperature of the secondary batteries during the series charging period exceeds the first threshold, all the secondary batteries are not switched from series charging to pulse charging. Only the secondary batteries that exceed the first threshold are switched to pulse charging, and the other secondary batteries are continuously charged in series.
[0053]
FIG. 12 is a circuit configuration diagram of a connection switching circuit 3B provided in the charging apparatus according to the third embodiment of the present invention.
In the figure, each of the secondary batteries 41 to 44 is connected with a backflow prevention diode D1 to D4 and switches SW2, SW8, and SW5 in series. When the switches SW2, SW8, and SW5 are turned on, the secondary batteries 41 to 44 are turned on. The secondary batteries 41 to 44 are connected in series between the charging terminals 2a and 2b.
[0054]
In addition, a switch SW1 is provided between the charging terminal 2a and the secondary battery 42. When the switch SW1 is turned on, the secondary battery 41 is bypassed from the charging path. Further, between the negative terminal of the secondary battery 41 and the negative terminal of the secondary battery 42, between the negative terminal of the secondary battery 42 and the negative terminal of the secondary battery 44, and between the negative terminal of the secondary battery 43 and the secondary terminal. Switches SW3, SW9, and SW6 are provided between the negative terminal of the secondary battery 44, respectively. When the switch SW3 is turned on, the secondary battery 42 is bypassed from the charging path. When the switch SW6 is turned on, the secondary battery 44 is bypassed from the charging path. When the switch SW9 is turned on, the secondary batteries 43 and 44 are bypassed from the charging path.
[0055]
Furthermore, switches SW7 and SW4 are provided between the charging terminal 2a and the positive terminal of the secondary battery 43, and between the positive terminal of the secondary battery 43 and the positive terminal of the secondary battery 44, respectively. When the switch SW7 is turned on, the secondary batteries 41 and 42 are bypassed from the charging path. When the switch SW4 is turned on, the secondary battery 43 is bypassed from the charging path.
[0056]
On the other hand, the charge control circuit performs charge control according to the following procedure. FIG. 13 is a flowchart showing the control procedure and control contents. The overall configuration of the charging device and the configuration of the charging control circuit are the same as those shown in FIGS. 1 and 3, respectively, and will be described below with reference to FIGS.
[0057]
When the secondary batteries 41 to 44 to be charged are mounted on the battery holder, the charging control circuit 9A first generates a switch control signal SWC for serial charging and supplies it to the switch driving circuit 10 in step 13a. As a result, a switch driving signal for connecting the secondary batteries 41 to 44 to the charging power source 1 in series is output from the switch driving circuit 10. Therefore, in the connection switching circuit 3B, the switches SW2, SW8, and SW5 are turned on, and the other switches SW1, SW3, SW4, SW6, SW7, and SW9 are all turned off. Therefore, the charging current output from the charging power source 1 is diode D1-secondary battery 41-switch SW2-diode D2-secondary battery 42-switch SW8-diode D3-secondary battery 43-switch SW5-diode D4-second. It flows along the path of the secondary battery 44. That is, the secondary batteries 41 to 44 are charged in series.
[0058]
In addition, during the period in which the series charging is performed, the charging control circuit 9A performs temperature monitoring for each of the secondary batteries 41 to 44 and charging mode switching control based on the monitoring result. That is, first, one of the secondary batteries 41 to 44 (for example, 41) is selected in step 13b, and the temperature detection data THS of the selected secondary battery 41 is fetched from the temperature detection circuit 8 in step 13c. Then, the detected temperature represented by the captured temperature detection data THS is compared with the first threshold value in step 13e, and if the detected temperature of the secondary battery 41 does not exceed the first threshold value, The process returns from step 13f to step 13b.
[0059]
Next, the charging control circuit 9A selects a secondary battery (for example, 42), captures the temperature detection data for the secondary battery 42, and calculates the detected temperature represented by the data and the first threshold value. Perform the comparison process. Similarly, the remaining secondary batteries 43 and 44 receive the temperature detection data THS, respectively, and execute a comparison process between the detected temperature represented by this data and the first threshold value.
[0060]
Now, let us assume that, for example, the temperature of the secondary battery 42 exceeds a first threshold value (for example, 50 ° C.) during the above series charging period. Then, the charging control circuit 9A shifts from step 13e to step 13g, where the switch control signal SWC for switching the charging mode for the secondary battery 42 to the pulse charging mode is generated and supplied to the switch driving circuit 10.
[0061]
As a result, in the connection switching circuit 3B, the switches SW2, SW8, SW5 are turned on and the switches SW1, SW3, SW4, SW6, SW7, SW9 are turned off, and the switches SW3, SW8, SW5 are turned on. In addition, the state in which the switches SW1, SW2, SW4, SW6, SW7, and SW9 are turned off is repeated at a constant cycle. Therefore, the secondary batteries 41, 43, and 44 are continuously charged with a large current in the series charging mode, but the secondary battery 42 is intermittently charged with a small current in the pulse charging mode. FIG. 15A shows the charging operation timing when pulse charging is performed only on the secondary battery 42.
[0062]
Further, for the secondary battery 42 during the pulse charging, the charging control circuit 9A determines full charge in step 13h. The determination of the full charge is performed by fetching the temperature detection data THS of the secondary battery 42 from the temperature detection circuit 8 at regular time intervals to obtain the temperature rise rate and comparing the temperature rise rate with a threshold value. . As a result of this determination, when the rate of temperature increase of the secondary battery 42 exceeds the threshold value, the charging control circuit 9A disconnects the secondary battery 42 from the charging power source 1 in step 13i. Note that the threshold value of the temperature increase rate is set to 0.8 ° C./1 minute, for example, as in the first embodiment.
[0063]
Similarly, for the other secondary batteries 41, 43, and 44, when the detected temperature exceeds the first threshold value, the process of switching the charging mode from the series charging mode to the pulse charging mode for the secondary battery is performed. The charging in the pulse charging mode is performed until the secondary battery is fully charged. Then, when it is detected in step 13j that all the secondary batteries 41 to 44 have reached full charge, the charge control circuit 9A ends the charge control.
[0064]
As described above, in the third embodiment, the temperature of each of the secondary batteries 41 to 44 during series charging is monitored, and each time a secondary battery whose temperature exceeds the first threshold is detected, Charging is performed by switching the charging mode to the pulse charging mode for the secondary battery, and series charging is continued for the other secondary batteries.
[0065]
Therefore, it is possible to continue the series charging as long as possible for the secondary battery whose temperature does not reach the first threshold while individually suppressing the temperature rise of each of the secondary batteries 41 to 44. Thus, it is possible to significantly reduce the time required for charging all the secondary batteries 41 to 44 while preventing the battery from being deteriorated in temperature.
[0066]
(Fourth embodiment)
In the fourth embodiment of the present invention, when the temperature of the secondary battery during the series charging period exceeds the first threshold value, only the secondary battery whose temperature exceeds the first threshold value is detected. Switch to pulse charging and continue the series charging for the other secondary batteries. And when the temperature of the secondary battery in which the said pulse charge period is performed falls below the 2nd threshold value, the charge mode of this secondary battery is switched again to the serial charge mode, and series charge is performed again. Thereafter, the series charging and the pulse charging are repeated based on the detected temperature of the secondary battery until the battery is fully charged.
[0067]
The charge control circuit according to this embodiment executes charge control according to the following procedure. FIG. 14 is a flowchart showing the control procedure and control contents. The same parts as those in FIG. The overall configuration of the charging apparatus and the configuration of the charging control circuit are the same as those in FIGS. 1 and 7, respectively, and will be described below with reference to FIGS.
[0068]
For the secondary battery (for example, 42) that has shifted to pulse charging, the charging control circuit 9B takes in the temperature detection data THS of the secondary battery 42 from the temperature detection circuit 8 in step 14a. Then, it is determined whether or not the detected temperature of the secondary battery 42 has fallen below the second threshold value. As a result of the determination in step 14a, when the detected temperature of the secondary battery 42 falls below the second threshold value, the charge control circuit 9B determines that the secondary battery 42 is again in a state in which series charging is possible. Return to step 13a.
[0069]
In step 13a, the charging control circuit 9B performs switch control for connecting the secondary battery 42 to the charging power source 1 in series with respect to the connection switching circuit 3B. As a result, the secondary battery 42 is serially connected to the charging power source 1 together with the other secondary batteries 41, 43, and 44, and is subsequently charged in series. FIG. 15B is a timing chart showing the charging operation of the secondary batteries 41 to 44 in this case. Note that the second threshold value is set to a value lower than the first threshold value by a certain value, as in the second embodiment. For example, if the first threshold is 50 ° C., it is set to 48 ° C., which is 2 ° C. lower than this value.
[0070]
Thereafter, for example, as shown in FIG. 15B, the charging control circuit 9B switches from the series charging mode to the pulse charging mode in steps 13b to 13f based on the detected temperature for each of the secondary batteries 41 to 44. Then, the switching from the pulse charging mode to the series charging mode in step 14a and step 13a is repeated.
[0071]
Further, the charging control circuit 9B determines whether or not the secondary battery that is charged in the pulse charging mode is fully charged in step 14b while executing the switching control of the charging mode. The determination of the full charge is made by calculating a temperature increase rate based on the temperature of the secondary battery periodically detected by the temperature detection circuit 8, and comparing the temperature increase rate with a threshold value.
[0072]
Now, for example, assume that the detected temperature of the secondary battery 42 being charged in the pulse charge mode has risen continuously for a predetermined time. That is, it is assumed that the temperature increase rate of the secondary battery 44 exceeds the threshold value. Then, the charging control circuit 9B disconnects the secondary battery 42 from the charging power source 1 in step 14c and stops supplying the charging current. For the other secondary batteries 41, 43, 44, when the rate of temperature rise exceeds the threshold during the period of pulse charging, the charging current is cut off from the charging power source 1 and the supply of charging current is stopped. To do.
[0073]
As described above, according to the fourth embodiment, similarly to the third embodiment, the switching control from the series charge mode to the pulse charge mode is performed individually for each secondary battery according to the detected temperature. Moreover, even if the secondary battery has once shifted to the pulse charging mode, if the temperature falls below the second threshold value, it returns to the serial charging mode again and is charged with a large current. Therefore, while suppressing the temperature rise of each of the secondary batteries 41 to 44 individually, the secondary battery whose temperature does not reach the first threshold value, and even if the temperature once reaches the first threshold value. Thereafter, the secondary battery that has fallen below the second threshold can be continuously charged for as long as possible. For this reason, after preventing the temperature deterioration of the secondary batteries 41-44, the charge required time of all the secondary batteries 41-44 can further be shortened.
[0074]
(Other embodiments)
In each of the above embodiments, the secondary battery whose temperature increase rate exceeds the threshold during the pulse charging period is determined to be fully charged, and charging is stopped. However, the present invention is not limited to this, and the temperature of each secondary battery is periodically sampled during the pulse charging period and the change is monitored. You may make it determine with a full charge with having reached.
[0075]
In each of the above embodiments, the first and second threshold values and the temperature increase rate threshold value are fixed values. However, it may be variably set according to room temperature, the type or brand of the secondary battery, and the like. This can be realized by detecting the temperature immediately before the start of charging with the temperature detection element as room temperature and optically reading the type or brand of the attached secondary battery.
[0076]
Furthermore, a means for monitoring a contact failure of the secondary battery with respect to the terminal of the battery holder and detecting battery non-connection or battery abnormality is provided. Then, when the battery is not connected or the battery abnormality is detected by the detection means, the secondary battery may be disconnected from the charging power source.
[0077]
Further, in the third embodiment, when a secondary battery whose temperature exceeds the first threshold is detected among the four secondary batteries 41 to 44 during the series charging period, only the secondary battery is detected. Was switched from serial charging to pulse charging. However, the present invention is not limited to this, and the charging mode may be switched to the pulse charging mode for the secondary battery whose temperature exceeds the first threshold and the secondary battery adjacent to the battery.
[0078]
Furthermore, in 2nd Embodiment, when the temperature of all the secondary batteries 41-44 fell below the 2nd threshold value during the time division pulse charge period, it was made to return charge mode to serial charge mode. . However, the present invention is not limited to this, and the charging mode for the secondary battery is switched to the series charging mode every time a secondary battery whose temperature is lower than the second threshold value is detected as in the fourth embodiment. May be.
[0079]
Further, in each embodiment, the case where the time-division pulse charging mode or the pulse charging mode is used as the second charging mode for performing the small current charging has been described as an example, but the parallel charging mode is used as the second charging mode. It is also possible to use it. In addition, the number of secondary batteries to be charged in parallel, the type of secondary battery, the circuit configuration of the connection switching circuit and the charging control circuit, the charging control procedure and the control contents, etc. are variously modified without departing from the scope of the present invention. Can be implemented.
[0080]
In short, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.
[0081]
【The invention's effect】
As described above in detail, in the present invention, first, the plurality of secondary batteries are connected in series to the charging power source to perform large current charging in the first charging mode, and charging in the first charging mode is performed. Each of the plurality of secondary batteries is monitored during a period, and when a secondary battery having a temperature exceeding a preset first threshold is detected among the plurality of secondary batteries, Only the secondary battery in which the temperature rise is detected is connected in parallel or intermittently to the charging power source, and the secondary battery is charged in the second charging mode with a smaller current than the first charging mode. The other secondary batteries continue to be charged in the first charging mode. I am doing so.
Therefore, according to the present invention, a secondary battery charging method capable of always performing safe charging while suppressing the temperature increase of each secondary battery regardless of the number of secondary batteries charged in parallel and the initial conditions. And a charging device and a charging control program thereof.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a charging apparatus according to a first embodiment of the present invention.
2 is a circuit diagram showing a configuration of a connection switching circuit provided in the charging device shown in FIG. 1;
3 is a block diagram showing a functional configuration of a charge control circuit provided in the charging device shown in FIG. 1;
4 is a flowchart showing a charge control procedure and control contents by the charge control circuit shown in FIG. 3;
FIG. 5 is a diagram showing timing of a charging operation performed in accordance with the flowchart shown in FIG.
6 is a diagram showing a change characteristic of a charging voltage and a temperature characteristic of a charging operation performed according to the flowchart shown in FIG.
FIG. 7 is a circuit diagram showing a functional configuration of a charge control circuit provided in a charging apparatus according to a second embodiment of the present invention.
FIG. 8 is a flowchart showing a charge control procedure and control contents by the charge control circuit shown in FIG. 7;
FIG. 9 is a diagram showing the timing of a charging operation performed in accordance with the flowchart shown in FIG.
FIG. 10 is a diagram showing a change characteristic of a charging voltage and a temperature characteristic of a charging operation performed according to the flowchart shown in FIG.
FIG. 11 is a diagram showing a comparison of discharge capacities of secondary batteries when charging mode switching is not repeated and when switching is not repeated.
FIG. 12 is a circuit diagram showing a configuration of a connection switching circuit provided in a charging apparatus according to a third embodiment of the present invention.
FIG. 13 is a flowchart showing a control procedure and control contents when charging is performed using the connection switching circuit shown in FIG. 12;
FIG. 14 is a flowchart showing a charging control procedure and control contents in a fourth embodiment of the present invention.
15 is a diagram showing the timing of a charging operation performed according to the flowcharts shown in FIGS. 13 and 14. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Charging power supply, 2a, 2b ... Charging terminal, 3A, 3B ... Connection switching circuit, 4 ... Secondary battery module, 6 ... Current detection circuit (I-DET), 7 ... Voltage detection circuit (V-DET), 8 ... temperature detection circuit (TH-DET), 9A, 9B ... charge control circuit, 10 ... switch drive circuit, 41-44 ... secondary battery, 51-54 ... temperature detection element, 90 ... CPU, 91 ... I / O, 92A, 92B ... program memory, 92a ... first connection switching control program, 92b ... charge termination control program, 92c ... second connection switching control program, 93 ... data memory.

Claims (9)

充電電源の出力をもとに複数の二次電池を並行して充電する二次電池の充電方法において、
前記複数の二次電池を前記充電電源に対し直列接続して、前記複数の二次電池に対し第１の充電モードによる充電を行う過程と、
前記第１の充電モードによる充電を行っている期間に、前記複数の二次電池の温度をそれぞれ監視する過程と、
前記第１の充電モードによる充電を行っている二次電池の温度が予め設定された第１のしきい値を超えたとき、当該温度上昇が検出された二次電池のみを前記充電電源に対し並列接続又は間欠接続してこの二次電池に対し前記第１の充電モードより小電流の第２の充電モードによる充電を行い、他の二次電池に対しては前記第１の充電モードによる充電を継続する過程と
を具備することを特徴とする二次電池の充電方法。In the secondary battery charging method of charging a plurality of secondary batteries in parallel based on the output of the charging power supply,
Connecting the plurality of secondary batteries in series with the charging power source, and charging the plurality of secondary batteries in a first charging mode;
Monitoring the temperature of each of the plurality of secondary batteries during a period of charging in the first charging mode;
When the temperature of the secondary battery charging in the first charging mode exceeds a preset first threshold value, only the secondary battery in which the temperature rise is detected is supplied to the charging power source. In parallel connection or intermittent connection, the secondary battery is charged in the second charging mode with a smaller current than in the first charging mode, and the other secondary batteries are charged in the first charging mode. And a process for continuing the charging. 前記第２の充電モードによる充電を行っている二次電池の温度を監視する過程と、
前記第２の充電モードによる充電を行っている二次電池の温度が前記第１のしきい値より低く設定された第２のしきい値未満に低下したとき、当該温度低下が検出された二次電池の前記充電電源に対する接続状態を前記並列接続又は間欠接続から前記直列接続に切り替えて、この切り替えた二次電池に対し前記第１の充電モードによる充電を再度行う過程と
を、さらに具備することを特徴とする請求項１記載の二次電池の充電方法。Monitoring the temperature of the secondary battery charging in the second charging mode;
When the temperature of the secondary battery that is charging in the second charging mode falls below a second threshold set lower than the first threshold, the temperature drop is detected. A step of switching the connection state of the secondary battery to the charging power source from the parallel connection or intermittent connection to the series connection, and charging the switched secondary battery in the first charge mode again. The method for charging a secondary battery according to claim 1 . 前記第２の充電モードによる充電を行っている二次電池の温度変化特性を監視する過程と、
前記第２の充電モードによる充電を行っている二次電池の温度変化特性が予め設定した満充電に対応する条件を満たしたとき、当該満充電の条件を満たした二次電池を前記充電電源から切り離す過程と
を、さらに具備することを特徴とする請求項１又は２記載の二次電池の充電方法。Monitoring a temperature change characteristic of a secondary battery that is charging in the second charging mode;
When the temperature change characteristic of the secondary battery that is charging in the second charging mode satisfies a condition corresponding to a preset full charge, a secondary battery that satisfies the full charge condition is removed from the charging power source. The method for charging a secondary battery according to claim 1 , further comprising a separation step. 充電電源の出力をもとに複数の二次電池を並行して充電する充電装置において、
前記充電電源に対する前記複数の二次電池の接続状態を、直列接続と並列接続との間或いは直列接続と間欠接続との間で切り替える接続切替手段と、
前記複数の二次電池の温度をそれぞれ検出する温度検出手段と、
前記温度検出手段により検出される前記複数の二次電池の温度に基づいて前記接続切替手段を制御する充電制御手段と
を具備し、
前記充電制御手段は、
前記接続切替手段により前記複数の二次電池を充電電源に対し直列接続させ、当該複数の二次電池に対して第１の充電モードによる充電を行わせる手段と、
前記第１の充電モードによる充電が行われている二次電池の温度を、予め設定された第１のしきい値と比較する第１の比較手段と、
前記第１の比較手段により、前記第１の充電モードによる充電が行われている二次電池の温度が前記第１のしきい値を超えたことが検出されたとき、前記接続切替手段により、当該温度上昇が検出された二次電池のみを前記充電電源に対し並列接続又は間欠接続させてこの二次電池に対し前記第１の充電モードより小電流の第２の充電モードによる充電を行わせ、他の二次電池に対しては前記第１の充電モードによる充電を継続させる手段と
を備えることを特徴とする二次電池の充電装置。In the charging device that charges a plurality of secondary batteries in parallel based on the output of the charging power supply,
Connection switching means for switching the connection state of the plurality of secondary batteries to the charging power source between series connection and parallel connection or between series connection and intermittent connection;
Temperature detecting means for detecting temperatures of the plurality of secondary batteries,
Charging control means for controlling the connection switching means based on the temperature of the plurality of secondary batteries detected by the temperature detection means,
The charge control means includes
Means for connecting the plurality of secondary batteries in series with a charging power source by the connection switching means, and charging the plurality of secondary batteries in a first charging mode;
First comparing means for comparing the temperature of the secondary battery being charged in the first charging mode with a preset first threshold;
When it is detected by the first comparison means that the temperature of the secondary battery being charged in the first charge mode exceeds the first threshold value, the connection switching means Only the secondary battery in which the temperature rise is detected is connected in parallel or intermittently to the charging power source, and the secondary battery is charged in the second charging mode with a smaller current than the first charging mode. A secondary battery charging device comprising: means for continuing charging in the first charging mode with respect to another secondary battery . 前記充電制御手段は、
前記第２の充電モードにより充電を行っている二次電池の温度を、前記第１のしきい値より低く設定された第２のしきい値と比較する第２の比較手段と、
前記第２の比較手段により、前記第２の充電モードにより充電を行っている二次電池の温度が前記第２のしきい値未満に低下したことが検出されたとき、前記接続切替手段により、前記温度低下が検出された二次電池を前記充電電源に対し直列接続させて、前記第１の充電モードによる充電を再度行わせる手段と
を、さらに備えることを特徴とする請求項４記載の二次電池の充電装置。The charge control means includes
A second comparing means for comparing the temperature of the secondary battery that is being charged in the second charging mode with a second threshold value set lower than the first threshold value;
When it is detected by the second comparison means that the temperature of the secondary battery that is being charged in the second charging mode has dropped below the second threshold value, by the connection switching means, 5. The device according to claim 4 , further comprising means for connecting the secondary battery in which the temperature drop has been detected to the charging power source in series so that the charging in the first charging mode is performed again. Secondary battery charger. 前記充電制御手段は、
前記温度検出手段の検出結果をもとに、前記第２の充電モードにより充電を行っている二次電池の温度変化特性を監視する手段と、
前記第２の充電モードにより充電を行っている二次電池の温度変化特性が予め設定した満充電に対応する条件を満たしたとき、当該満充電の条件を満たした二次電池を前記充電電源から切り離す手段と
を、さらに具備することを特徴とする請求項４又は５記載の二次電池の充電装置。The charge control means includes
Means for monitoring a temperature change characteristic of the secondary battery that is charged in the second charging mode based on the detection result of the temperature detecting means;
When the temperature change characteristic of the secondary battery that is being charged in the second charging mode satisfies a condition corresponding to a preset full charge, a secondary battery that satisfies the full charge condition is removed from the charging power source. The secondary battery charging device according to claim 4, further comprising means for separating. 充電電源に対する複数の二次電池の接続状態を、直列接続と並列接続又は間欠接続との間で切り替える接続切替回路と、前記複数の二次電池の温度をそれぞれ検出する温度検出回路と、前記温度検出回路により検出される前記複数の二次電池の温度に基づいて前記接続切替回路を制御するコンピュータとを備える二次電池の充電装置で使用される充電制御プログラムであって、
前記接続切替回路により前記複数の二次電池を充電電源に対し直列接続させ、当該複数の二次電池に対し第１の充電モードによる充電を行わせる処理と、
前記第１の充電モードによる充電を行っている二次電池の温度を予め設定された第１のしきい値と比較する処理と、
前記第１の比較手段により、第１の充電モードによる充電を行っている二次電池の温度が前記第１のしきい値を超えたことが検出されたとき、前記接続切替回路により、当該温度上昇が検出された二次電池のみを前記充電電源に対し並列接続又は間欠接続させてこの二次電池に対し前記第１の充電モードよりも小電流の第２の充電モードによる充電を行わせ、他の二次電池に対しては前記第１の充電モードによる充電を継続させる処理と
を、前記コンピュータに実行させることを特徴とする充電制御プログラム。A connection switching circuit for switching a connection state of a plurality of secondary batteries to a charging power source between a series connection and a parallel connection or an intermittent connection; a temperature detection circuit for detecting temperatures of the plurality of secondary batteries; and the temperature A charge control program used in a secondary battery charging device comprising: a computer that controls the connection switching circuit based on temperatures of the plurality of secondary batteries detected by a detection circuit;
A process of connecting the plurality of secondary batteries in series with a charging power source by the connection switching circuit, and charging the plurality of secondary batteries in a first charging mode;
A process of comparing the temperature of the secondary battery that is being charged in the first charging mode with a preset first threshold value;
When it is detected by the first comparison means that the temperature of the secondary battery that is charging in the first charging mode exceeds the first threshold value, the connection switching circuit detects the temperature. Only the secondary battery in which the rise is detected is connected in parallel or intermittently to the charging power source, and the secondary battery is charged in the second charging mode with a smaller current than the first charging mode, A charge control program for causing the computer to execute processing for continuing charging in the first charge mode for another secondary battery . 前記温度検出回路により検出された、前記第２の充電モードにより充電を行っている二次電池の温度を前記第１のしきい値より低く設定された第２のしきい値と比較する処理と、
前記比較処理により、前記第２の充電モードにより充電を行っている二次電池の温度が前記第２のしきい値未満に低下したことが検出されたとき、前記接続切替回路により、前記温度低下が検出された二次電池の前記充電電源に対する接続状態を前記並列接続又は間欠接続から前記直列接続に切り替えて、この切り替えられた二次電池に対し前記第１の充電モードによる充電を再度行わせる処理と
を、さらに前記コンピュータに実行させることを特徴とする請求項７記載の充電制御プログラム。A process of comparing the temperature of the secondary battery, which is detected by the temperature detection circuit, being charged in the second charging mode with a second threshold value set lower than the first threshold value; ,
When the comparison process detects that the temperature of the secondary battery that is being charged in the second charging mode has dropped below the second threshold value, the connection switching circuit causes the temperature drop. The connection state of the secondary battery in which the battery is detected is switched from the parallel connection or the intermittent connection to the series connection, and the recharged secondary battery is charged again in the first charging mode. The charge control program according to claim 7 , further causing the computer to execute a process. 前記温度検出回路の検出結果をもとに、前記第２の充電モードにより充電を行っている二次電池の温度変化特性を監視する処理と、
前記温度特性の監視処理により、前記第２の充電モードにより充電を行っている二次電池の温度変化特性が予め設定した満充電に対応する条件を満たすことが検出されたとき、当該満充電の条件を満たす二次電池を前記充電電源から切り離す処理と
を、さらに前記コンピュータに実行させることを特徴とする請求項７又は８記載の充電制御プログラム。Based on the detection result of the temperature detection circuit, the process of monitoring the temperature change characteristics of the secondary battery that is charging in the second charging mode;
When it is detected by the temperature characteristic monitoring process that the temperature change characteristic of the secondary battery that is charged in the second charging mode satisfies a condition corresponding to a preset full charge, the full charge The charge control program according to claim 7 or 8 , further causing the computer to execute a process of disconnecting a secondary battery that satisfies a condition from the charging power source.
JP2003158404A 2003-06-03 2003-06-03 Secondary battery charging method, charging device and charging control program therefor Expired - Fee Related JP4060756B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2003158404A JP4060756B2 (en) 2003-06-03 2003-06-03 Secondary battery charging method, charging device and charging control program therefor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2003158404A JP4060756B2 (en) 2003-06-03 2003-06-03 Secondary battery charging method, charging device and charging control program therefor

Publications (2)

Publication Number Publication Date
JP2004364387A JP2004364387A (en) 2004-12-24
JP4060756B2 true JP4060756B2 (en) 2008-03-12

Family

ID=34051822

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2003158404A Expired - Fee Related JP4060756B2 (en) 2003-06-03 2003-06-03 Secondary battery charging method, charging device and charging control program therefor

Country Status (1)

Country Link
JP (1) JP4060756B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104901365A (en) * 2015-05-22 2015-09-09 聊城大学 Lead-acid battery pulse charging control system

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6312846B1 (en) 1999-11-24 2001-11-06 Integrated Fuel Cell Technologies, Inc. Fuel cell and power chip technology
US8834700B2 (en) 1999-11-24 2014-09-16 Encite, Llc Method and apparatus for electro-chemical reaction
US8980492B2 (en) 1999-11-24 2015-03-17 Encite Llc Method and apparatus for controlling an array of power generators
US8518594B2 (en) 1999-11-24 2013-08-27 Encite, Llc Power cell and power chip architecture
US9819037B2 (en) 2006-03-02 2017-11-14 Encite Llc Method and apparatus for cleaning catalyst of a power cell
EP2432062B1 (en) * 2006-03-02 2016-03-02 Encite LLC Power cell architecture
JP4973075B2 (en) * 2006-09-07 2012-07-11 日産自動車株式会社 Power supply
JP4727562B2 (en) * 2006-12-12 2011-07-20 日本電信電話株式会社 Charging method and charging circuit
US8586256B2 (en) 2007-07-10 2013-11-19 Seiko Instruments Inc. Power supply apparatus
JPWO2009110221A1 (en) * 2008-03-03 2011-07-14 パナソニック株式会社 Charging method and charging device
TW201039532A (en) * 2009-04-30 2010-11-01 Well Shin Technology Co Ltd Charge circuit for series connection battery group
JP5987298B2 (en) * 2011-11-15 2016-09-07 富士電機株式会社 Lithium-ion battery charging method
JP6256214B2 (en) 2014-06-13 2018-01-10 トヨタ自動車株式会社 Electric vehicle and control method thereof
JP6361559B2 (en) 2014-06-20 2018-07-25 トヨタ自動車株式会社 Vehicle control device
JP6890285B2 (en) * 2016-03-31 2021-06-18 東亜ディーケーケー株式会社 Controller with battery diagnostic function of uninterruptible power supply and its diagnostic method
JP2017184589A (en) * 2016-03-31 2017-10-05 東亜ディーケーケー株式会社 Charge discharge controller of uninterruptible power supply and charge discharge control method thereof
CN112909364B (en) * 2019-12-03 2022-08-09 北京小米移动软件有限公司 Charging method and device, terminal equipment and storage medium

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05328629A (en) * 1992-05-26 1993-12-10 Sanyo Electric Co Ltd Battery charger
JP3952585B2 (en) * 1998-03-02 2007-08-01 東芝電池株式会社 Secondary battery charger
JP3669234B2 (en) * 1999-11-15 2005-07-06 新神戸電機株式会社 Charge control device for battery pack
JP2001169471A (en) * 1999-12-02 2001-06-22 Toshiba Battery Co Ltd Secondary cell device
JP2001178011A (en) * 1999-12-10 2001-06-29 Toshiba Battery Co Ltd Secondary cell device
JP4079590B2 (en) * 2000-12-28 2008-04-23 三洋電機株式会社 Pack battery and battery charging method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104901365A (en) * 2015-05-22 2015-09-09 聊城大学 Lead-acid battery pulse charging control system

Also Published As

Publication number Publication date
JP2004364387A (en) 2004-12-24

Similar Documents

Publication Publication Date Title
JP4060756B2 (en) Secondary battery charging method, charging device and charging control program therefor
JP3886389B2 (en) Battery pack charging device and charging method
US8054044B2 (en) Apparatus and method for balancing of battery cell'S charge capacity
JPH09285028A (en) Over-charge preventing circuit, over-discharge preventing circuit, and charge and discharge controlling circuit
EP0773618A2 (en) Battery charging system
JP2007325324A (en) Charging system, battery pack and its charging method
US20210399558A1 (en) Battery control unit and battery system
US11843267B2 (en) Battery control unit and battery system
JPH0946916A (en) Charging controller
JP2005160233A (en) Battery pack and cell battery pack
JP2003274570A (en) Constant-current constant-voltage charging method, and charger
US6137268A (en) System with limited long-time-averaged battery charging rate
JP2004364388A (en) Charger of secondary battery and charge control program thereof
JP2000166103A (en) Charging discharging control method
JP2003158827A (en) Charging method, charging device, and discharging controller for lithium ion battery
JP3421534B2 (en) Overcharge prevention circuit, overdischarge prevention circuit and charge / discharge control circuit
JP2002313439A (en) Battery pack
JP2005218174A (en) Battery pack monitor and battery pack
JP2000050516A (en) Overcharging preventing circuit, overdischarging preventing circuit, and charging discharging control circuit
JP3118387B2 (en) Method and apparatus for charging secondary battery
JP2002238179A (en) Charging device and method of secondary battery
US20220352729A1 (en) Battery pack, and abnormality monitoring method for same
JPH07203634A (en) Charger for secondary cell
JP2005224024A (en) Combined battery set and battery pack
JP2005027435A (en) Charging equipment

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20060602

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20070709

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20070717

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20070914

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20071218

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20071220

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20101228

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

LAPS Cancellation because of no payment of annual fees