JP4178141B2 - Charging apparatus and charging method - Google Patents

Description

  The present invention relates to a charging device and a charging method, and more particularly to a technique for ensuring both deterioration prevention and operating time of a rechargeable battery.

  With the recent development of portable electronic devices such as notebook personal computers, PDAs, and mobile phones, there is a demand for further improvement in performance of batteries used in these electronic devices. Specifically, it is required not only to increase the capacity, reduce the size and weight, but also not to deteriorate even if frequently charged. Therefore, in order to meet such needs, a battery such as a lithium ion secondary battery that does not cause a memory effect even when charged without full discharge has been developed and widely used.

  However, although the lithium ion secondary battery does not have a memory effect, there is a characteristic that deterioration of the battery, that is, reduction of the charge capacity can be accelerated when the battery is always in a fully charged state.

  For this reason, for example, when connected to a charger as in the technique described in Patent Document 1, charging is stopped when full charging is detected, and charging (complementary charging) is started again when a voltage drop is detected. Technology has been developed. By doing in this way, the operating time when using it remove | excluding from a charger is lengthened, and deterioration is prevented.

  Further, in Patent Document 1, when a charger is connected, the battery is once fully charged, and in the second and subsequent charging after the charging is stopped, the charging voltage at the time of charging is suppressed to a low level to thereby reduce the lithium ion battery. Is effectively prevented.

  The above charging process according to the background art will be described more specifically. FIG. 7 is a diagram showing the relationship between the time T when the battery is charged and the current I flowing through the battery or the voltage V of the battery.

  Here, it is assumed that the battery is in a fully discharged state at time zero. First, charging is started with a predetermined current Ip. That is, the charging current is constant at Ip (constant current charging). When charging progresses and it is detected that the battery voltage reaches the threshold value Vc (T = Tc), charging is stopped with a predetermined current Ip and charging is started with a predetermined voltage Vm (constant voltage charging). . When time elapses in this state, the battery voltage gradually approaches Vm. This asymptotic degree can be measured by a decrease in charging current. When it is detected that the charging current has decreased by a predetermined amount, it is determined that charging has ended, and charging is stopped.

  As described above, when the lithium ion secondary battery is continuously charged in a high voltage state, deterioration occurs. That is, the charging capacity is reduced, and the operating time of the apparatus using the battery as a driving power source is shorter than when the charging is not continued in a high voltage state. For this reason, the charging is stopped by first charging with a constant current and detecting that the charging current has decreased by a predetermined level, thereby avoiding applying an unnecessary high voltage to the battery.

  Further, since the battery is gradually discharged in the state where the charging is stopped, the voltage is detected even after the charging is stopped, and when the battery voltage is lowered by a predetermined amount, the charging (complementary charging) is started again. The time change of the battery voltage in this case is shown in FIG. When the charger is connected, the voltage during constant voltage charging is the first charging voltage (for example, 4.2 V) that maximizes the capacity during full charging within an allowable range, and charging is performed up to the first charging voltage. (That is, charge to Vm = 4.2V, for example). When the charging is completed, the charging is stopped, and when the battery voltage decreases to the reference voltage Vs, the charging is performed again.

However, if it does in this way, a battery will be put in a high voltage state (voltage state asymptotic to a full charge voltage) for every charge. Therefore, as shown in FIG. 9, after the second time, a technique for performing charging by lowering the voltage during constant voltage charging to, for example, a second charging voltage (a voltage lower than the first charging voltage, for example, 4.1 V) is disclosed in Patent Document 1. It is described in.
JP 2002-218668 A

  However, in the above conventional technique, in order to prevent a decrease in the operating time of the battery when the battery is removed from the charger, the battery is fully charged at least for the first time after being connected to the charger. There was a need. For this reason, although it was only the first time, there was a problem that the battery was charged at a high voltage and the battery deteriorated.

  In the first place, a battery is used to use a portable device without being connected to an AC power source supplied from a power plant or the like, and a charging voltage that is a voltage at the time of constant voltage charging as shown in FIG. As a result, there is a problem that the operating time of a device that uses the battery as a drive power source is shortened accordingly. More specifically, since the charge voltage becomes the second charge voltage (<first charge voltage) in the charge by the auxiliary charge after the detection of the full charge, for example, a mobile phone or the like is charged overnight and charged in the morning. When it is used after being removed from the battery, it is normally in a state after being supplemented repeatedly several times, so it is in a state of being charged at a low charge voltage (second charge voltage), and the first charge voltage Compared to charging with, the operating time has become shorter.

  As described above, it has not been possible to achieve both the prevention of deterioration of the rechargeable battery and the securing of the operation time.

  The present invention has been made to solve the above-described problems, and one of its purposes is to provide a charging device and a charging method that enable both prevention of deterioration of the rechargeable battery and securing of operating time.

  The charging device according to the present invention for solving the above-described problem is the case where the battery is charged a plurality of times, and the plurality of times when the battery voltage at the start of charging the battery is higher than a predetermined threshold voltage. The charging is performed so that the charging voltage at the time of constant voltage charging differs depending on the size of the ratio relationship quantity calculating means for calculating the ratio relation quantity indicating the ratio to the ratio and the calculated ratio relation quantity and the predetermined threshold ratio relation quantity. The charging voltage determining means for determining the voltage and the charging means for charging the battery with the determined charging voltage at the time of constant voltage charging.

  By doing in this way, since a charging voltage can be determined according to the battery voltage at the time of the charge start of the predetermined number of times, it becomes possible to prevent deterioration of the rechargeable battery and ensure operating time.

  In the charging device, the charging voltage determination unit determines the first charging voltage as the charging voltage at the constant voltage charging when the calculated ratio relation amount is smaller than the predetermined threshold ratio relation amount. The second charging voltage, which is a voltage lower than the first charging voltage, is set when the calculated supplemental relationship amount is larger than the predetermined threshold proportion relationship amount. The charging voltage is determined as a charging voltage at the time of voltage charging, and the supplementary charging start voltage is set as a second supplementary threshold value. The difference between the first supplementary threshold value and the second supplementary threshold value is determined by the first and second charging voltages. It may be determined according to the difference amount.

  In this way, when the battery voltage is reduced by a predetermined amount due to spontaneous discharge in the charge-stopped state, the amount of voltage reduction when performing recharging (complementary charging) depends on the charging voltage determined by the charging voltage determining means. Therefore, the auxiliary charging interval can be prevented from becoming excessively short, and the average voltage of the battery can be reliably reduced.

  Further, in the above charging apparatus, the determination of the charging voltage by the charging voltage determining means is performed when the power supply to the battery becomes possible and when the apparatus including the battery as a driving power source is turned on. It is good as well. In this way, since the charging voltage can be determined even when the power source of the apparatus including the battery as a driving power source is turned on, the battery is rarely carried and the battery consumption when carried is small. For a battery used in a large portable device, it is possible to more appropriately balance the prevention of deterioration of the rechargeable battery and the operation time.

  Furthermore, the charging device further includes a charging mode determining means for determining, as a charging mode, either a battery deterioration preventing mode for preventing deterioration of the battery or a battery operating time securing mode for extending the operating time of the battery. The charging voltage determining means determines whether charging is performed during constant voltage charging depending on whether the calculated proportion relationship amount is higher than a predetermined threshold proportion relationship amount when the determined charging mode is a battery deterioration prevention mode. The charging voltage may be determined so that the voltages are different. In this way, the battery user can determine the mode himself. That is, for example, when it is desired to use the battery without charging for a long time, the battery operating time securing mode can be selected, and when priority is given to preventing the deterioration, the battery deterioration preventing mode can be selected.

  In addition, the charging method according to the present invention indicates a ratio of the plurality of times when the battery voltage is higher than a predetermined threshold voltage when charging the battery a plurality of times. Charging for determining the charging voltage so that the charging voltage at the time of constant voltage charging differs depending on the magnitude of the ratio relationship quantity calculating step for calculating the ratio relation quantity and the calculated ratio relation quantity and the predetermined threshold ratio relation quantity The method includes a voltage determining step and a charging step of charging the battery with the determined charging voltage at the time of constant voltage charging.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a functional block diagram of a charging apparatus 10 according to the first embodiment of the present invention. The figure shows a state in which a battery to be charged is connected. First, the charging device 10 includes a charging unit 20 and a power supply unit 30, and the charging unit 20 and the power supply unit 30 are connected by a terminal 82 and a terminal 83. The charging unit 20 is connected to the battery unit 40 including the battery 43 to be charged by the terminal 80 and the terminal 81. The load 50 is a device provided with the battery 43 as a driving power source, and a mobile phone is an example. The power supply unit 30 includes a charger 32, and the charger 32 is connected to a 100 V AC power supply 60.

  The charging unit 20 includes a charging control unit 21, a determination unit 22, a memory unit 23, a voltage detection unit 24, a constant voltage circuit 25, a constant current circuit 26, a charging voltage control ON / OFF operation unit 27, a current detection unit 28, and an electric resistance. 29. The charging control unit 21 controls each unit of the charging unit 20 and controls the charging process of the battery 43 in the charging device 10.

  During constant current charging, the charging control unit 21 controls the constant current circuit 26 so as to generate a predetermined current (Ip in FIG. 7). When the constant voltage charging starts, the charging control unit 21 stops controlling the constant current circuit 26 so as to generate a predetermined current, and generates a predetermined voltage (Vm in FIG. 7). The voltage circuit 25 is controlled. Then, when it is detected that the charging current has decreased by a predetermined amount, it is determined that charging has ended, and the charging control unit 21 stops charging. That is, the constant voltage circuit 25 is controlled so that the voltage generated by the constant voltage circuit 25 becomes zero.

  The voltage detection unit 24 detects the battery voltage (battery voltage, voltage V in FIG. 7) of the battery 43 and notifies the charge control unit 21 of it. The constant voltage circuit 25 controls the charging voltage so that it can be charged with a constant charging voltage. The constant current circuit 26 controls the charging current so that charging can be performed with a constant charging current. One of the constant voltage circuit 25 and the constant current circuit 26 is configured to operate according to an instruction from the charge control unit 21. The current detection unit 28 detects the current flowing through the battery 43 by detecting the current flowing through the electric resistance 29 (charging current, current I in FIG. 7), and notifies the charging control unit 21 of the current. The determination unit 22, the memory unit 23, and the charging voltage control ON / OFF operation unit 27 will be described later.

  The battery unit 40 includes an overcharge / overdischarge detection unit 41, a protection circuit 42, and a battery 43. Since the battery 43 deteriorates due to overcharge or overdischarge, the overcharge / overdischarge detection unit 41 determines that the charge has exceeded a predetermined voltage or the voltage drop due to discharge has a predetermined value so that the battery 43 is not overcharged or overdischarged. It is detected that it has been exceeded and outputted to the protection circuit 42. The protection circuit 42 cuts off the circuit so as to stop charging or discharging according to the detection result.

  The battery unit 40 is often traded as a single battery pack. The charging unit 20 is often included in a device using the battery 43 as a driving power source. And the battery part 40 is used in the state normally connected to the apparatus containing the charging part 20, and when charging, it starts charging in response to connecting the charging part 20 to the power supply part 30 in many cases. In the present embodiment, the description will be given assuming that the battery 43 is a lithium ion secondary battery.

  The time change of the battery voltage in the present invention is shown in FIG. As shown in the figure, the battery voltage in the battery deterioration prevention mode to be described later of the present embodiment is always Vm or less (eg, 4.1 V), and the battery 43 is not placed in a high voltage state. It is possible to prevent battery deterioration.

  In the present embodiment, the operation time can be secured even if charging is performed in this way. The process for this will be described with reference to the flowchart of the process shown in FIG.

  FIG. 3 is a process flow diagram showing the first embodiment of the present invention. First, when all of the terminals 80 to 83 are connected and further supplied with power from the AC power supply 60 (that is, when charging is started by supplying power to the battery 43), the voltage detection unit 24 sets the battery voltage. It detects by measuring Vbat (battery voltage at the start of charging) (S101), and outputs it to the charging control unit 21. Thus, the charge control unit 21 functions as a battery voltage information acquisition unit that acquires battery voltage information indicating a charging voltage at the start of charging. Then, the determination unit 22 receives the Vbat from the charge control unit 21, compares the received Vbat with the first threshold voltage V1 stored in the memory unit 23 in advance (S102), and compares the comparison result with the voltage range of the Vbat. It is acquired as battery voltage range information at the start of charging shown. Furthermore, the battery voltage range information at the start of charging for the past N−1 times indicating the comparison result in S102 for the past N−1 times stored in the memory unit 23 by the process of S104 described later is read. And the battery voltage range information at the time of N charge starting which shows the comparison result for N times which combined the comparison result in S102 and the comparison result for the past N-1 times is acquired (S103).

  Here, the battery voltage range information at the start of charging stored in the memory unit 23 will be described with reference to FIG. FIG. 4 is an example of the charging start battery voltage range information stored in the memory unit 23. As shown in the figure, “3 lights” or “2 lights” are stored in association with the number of times. This is because when the battery 43 is a driving power source for a mobile phone, a battery remaining amount meter (for example, the remaining battery level is indicated by blinking of three lights) displayed on the display unit of the mobile phone starts charging. In this case, the value is shown.

  The display of the battery level meter is determined as follows. That is, the case where Vbat exceeds a certain first threshold voltage V1 is defined as “3 lamps” (that is, the boundary value between 3 lamps and 2 lamps = the first threshold voltage), Vbat is equal to or lower than the first threshold voltage V1, and the second The case where the threshold voltage V2 is exceeded is defined as “2 lamps” (that is, the boundary value between 2 lamps and 1 lamp = the second threshold voltage). More specifically, the first threshold voltage V1 is the battery voltage of the battery 43 when the remaining charge capacity of the battery 43 reaches 50% (for example, 2.1V which is 50% of the first charge voltage), the first threshold voltage. The voltage V1 can be determined as the battery voltage of the battery 43 when the remaining charge capacity of the battery 43 reaches 20% (for example, 0.84V, which is 20% of the first charge voltage).

  In this way, it is possible to confirm the battery level meter at the start of charging by linking the display of the battery level meter and the comparison result stored in the memory unit 23, as described later in “Battery degradation prevention mode”. "Or" battery operating time prevention mode "can be used as an index for determining whether to select.

  Returning to the description of FIG. The determination unit 22 overwrites the memory unit 23 by overwriting the N-1 charging start battery voltage range information from the new results out of the N charging starting battery voltage range information (S104). In addition, the determination unit 22 uses the battery voltage range information at the start of charging N times as a ratio relation amount indicating a ratio indicating that the battery voltage at the start of charging is higher than the first threshold voltage V1 (high voltage charge count ratio relation). It is determined whether or not (amount) is smaller than the usage tendency threshold ratio related amount (S105). Here, the usage trend threshold ratio related amount indicates whether the user of the battery 43 tends to charge frequently or whether it tends to charge after discharging to at least the first threshold voltage V1 or less. This is a threshold value for indicating. If the high voltage charge count ratio relation amount indicating the ratio indicating that the battery voltage at the start of charging is higher than the first threshold voltage V1 is less than the use tendency threshold ratio relation quantity, the user of the battery 43 is equal to or less than the first threshold voltage V1. It is determined that the battery tends to be charged after being discharged until the battery voltage at the start of charging is higher than the first threshold voltage V1. If it is above, it will be judged that the user of the battery 43 tends to charge frequently.

  In addition, the charging time ratio related quantity at the time of high voltage is the battery voltage range information at the start of charging indicating that the battery voltage at the start of charging is higher than the first threshold voltage V1 among the N battery voltage range information at the start of charging. May be a value obtained by dividing the number of times of charging (number of times of charging at high voltage) by N or the number of times of charging at high voltage itself. The usage tendency threshold ratio related quantity is a predetermined threshold M (M ≦ N) when the high voltage charge count ratio related quantity is the high voltage charge count itself, and the high voltage charge count ratio related quantity. Is a value obtained by dividing the number of times of charging at high voltage by N, the predetermined threshold value M / N is obtained.

  When the high voltage charge count ratio related amount is not smaller than the usage tendency threshold ratio related amount, the charge control unit 21 sets the voltage value at the constant voltage charge to the second charge voltage 4.1 V (S107). . That is, the constant voltage circuit 25 is set so that a voltage lower than the fully charged battery voltage by a predetermined voltage becomes a voltage value during constant voltage charging. On the other hand, when the high voltage charge count ratio related amount is smaller than the usage tendency threshold ratio related amount, the charge control unit 21 sets the voltage value at the constant voltage charge to the first charge voltage of 4.2 V (S108). That is, the constant voltage circuit 25 is set so that the fully charged battery voltage becomes a voltage value during constant voltage charging. In this way, in the case where the charging control unit 21 charges the battery a plurality of times (the latest N times), the battery voltage when starting the charging of the battery is higher than a predetermined threshold voltage (first threshold voltage). A ratio relation amount calculating means for calculating a high voltage charge count ratio relation amount indicating a ratio of the plurality of times in the case of high, and the calculated high voltage charge count ratio relation quantity and a predetermined usage tendency threshold ratio relation quantity It functions as a charging voltage determining means for determining the charging voltage so that the charging voltage at the time of constant voltage charging differs depending on the size.

  The specific values of the first charging voltage and the second charging voltage vary depending on the number of lithium ion battery cells included in the battery, for example. For example, when there is one cell (in the case of one cell), the first charging voltage is 4.2V and the second charging voltage is 4.1V. Further, the first charging voltage when there are two cells (in the case of two cells) is 8.4 V, and the first charging voltage when there are three cells (in the case of three cells) is 12.6 V.

  Then, the charging control unit 21 performs a charging operation with the set charging voltage (S108), determines whether or not the charging current has been reduced due to a decrease (S109), Charging is stopped (S110). Then, the battery voltage of the battery 43 is monitored (S111), and when the battery voltage becomes equal to or lower than the first supplement threshold value V3 (or the second supplement threshold value V3 ′) (S112), the charging operation (complementary charging operation) is performed again. I do. At this time, it may be repeated from S108 or may be repeated from S101.

  As described above, the charging voltage can be changed according to the battery voltage at the start of the past charging. That is, since the tendency about how much the battery 43 is used in a state where the user cannot be charged can be acquired, the operation time is sufficiently secured from the user's viewpoint by changing the charging voltage according to the tendency. At the same time, the charging voltage can be lowered to prevent deterioration of the rechargeable battery. In addition, when the portable device is used for a long time and the battery voltage when charging is started by connecting a charger is higher than a predetermined value (first threshold voltage), the usage tendency threshold ratio relation amount indicates. If it is smaller than the charging rate, set the charging voltage of the battery higher (set it to the first charging voltage) to increase the charged capacity, and it will take longer to use while charging on the desk or charge frequently If the battery voltage at the start of charging with a charger connected is higher than a predetermined value (first threshold voltage), such as when the battery is charged, the battery is charged. It is possible to prevent battery deterioration by setting the voltage low (set to the second charging voltage).

  In the first embodiment, the charging voltage is set in two stages. However, the charging voltage is set more finely according to the battery voltage at the start of charging (the nth threshold voltage is set as the threshold number of the battery remaining amount display). Therefore, the user's usage tendency can be more accurately reflected in the charging voltage, so that the user's satisfaction can be further increased.

  In the process of S112, when the charging voltage is the first charging voltage (that is, when the high voltage charging frequency ratio relation amount is smaller than the usage tendency threshold ratio relation amount), the first replenishment threshold V3 is used to charge the charging voltage. Is the second charging voltage (that is, when the high voltage charge count ratio related quantity is equal to or greater than the usage tendency threshold ratio related quantity), the second supplement threshold V3 ′ (<first supplement threshold V3) is used. Is preferred. Here, the difference amount between the first replenishment threshold value V3 and the second replenishment threshold value V3 ′ may be determined according to the difference amount between the values of the first charging voltage and the second charging voltage. Specifically, if the first charging voltage is 10% higher than the second charging voltage, the first replenishment threshold V3 is determined to be 10% larger than the second replenishment threshold V3 ′. Can do. By determining the first replenishment threshold value V3 and the second replenishment threshold value V3 ′ in this way, it is possible to prevent the interval of supplementary charging from becoming excessively narrow, and to ensure the average battery voltage of the battery 43. Can be lowered. The process of detecting that the battery voltage has decreased to the first replenishment threshold V3 or the second replenishment threshold V3 ′ may be performed by constantly monitoring the voltage, or confirming the battery voltage after a predetermined time has elapsed. May be performed. Further, without providing the first replenishment threshold V3 or the second replenishment threshold V3 ′, for example, supplementary charging may be started after a predetermined time has elapsed.

  In the charging voltage control ON / OFF operation unit 27 included in the charging unit 20 in the first embodiment, the user of the battery 43 extends the battery deterioration prevention mode in which the battery 43 is prevented from deteriorating or the operation time of the battery 43 is increased. An operation for selecting one of the battery operating time securing modes to be performed can be accepted. When the user selects the battery deterioration prevention mode, the charging voltage can be determined according to the battery voltage at the start of charging in the past by performing the processes of S101 to S107. Can be prevented. On the other hand, when the user selects the battery operating time securing mode, the processing of S106 and S107 is not performed, and the charging operation is always performed by setting the charging voltage to 4.2 V, whereby the battery 43 Can maximize uptime.

  Further, at the start of charging, in addition to the comparison with the first threshold voltage, the comparison with the second threshold voltage is also performed. When a charging voltage equal to or lower than the second threshold voltage is detected, the charging performed at least immediately after that is detected. As for (charging performed between the start of connection of the charger and the disconnection), the battery 43 can be used for as long as possible by setting the charging voltage during constant voltage charging to the first charging voltage. Also good.

  Next, a second embodiment of the present invention will be described. The second embodiment is preferably applied to a portable device that is often used in a charged state (connected to a charger), such as a notebook personal computer.

  That is, in many cases, the notebook personal computer does not often have a charger connection operation in the first place. When the charger is connected after being carried in a rare case, the battery voltage has the first probability with a considerable probability. It is below the threshold voltage V1. In such a case, in the first embodiment, the comparison result stored in the memory unit 23 is “2 lamps” at a considerable rate, and the set voltage during constant voltage charging is the first charging voltage. However, the second charging voltage is sufficient because it is practically hardly carried. In this embodiment, it is preferable to apply to a portable device that is rarely carried in this way and that consumes a large amount of battery power when carried.

  5 is obtained by replacing the charging unit 20 of the charging apparatus 10 in FIG. 1 with a charging unit 20a. In the charging unit 20a, the charging control unit 21 is replaced with the charging control unit 21a, and the power control unit 70 is connected to the charging control unit 21a. The power supply control unit 70 is a functional unit for controlling the power supply of a device that uses the battery 43 as a driving power supply. The power supply control unit 70 outputs an activation detection signal to the charge control unit 21a. The activation detection signal is a signal indicating that the apparatus whose power is controlled by the power controller 70 has been activated. As a more specific example, the apparatus is a notebook personal computer, and a signal indicating that the power of the notebook personal computer has been turned on is the activation detection signal. Alternatively, the device is a mobile phone, connected to a notebook personal computer, used as a modem, and in most cases when the notebook personal computer is used with a charger connected on a desk, the notebook personal computer A signal indicating that it is detected that the power is turned on may be an activation detection signal.

  In addition, when the connection of the charger is detected not only when the charger connection is detected by this activation detection signal but also when the above-mentioned device having the battery 43 such as a notebook personal computer as a driving power source is activated, the constant voltage charging is performed. The charging voltage control process is performed.

  FIG. 6 is a flowchart of processing in the second embodiment. As shown in the figure, the processing from S101 to S112 is the same as the processing in the first embodiment shown in FIG. What is characteristic in the second embodiment is that the process of S120 is added. When the activation detection signal is input, the charging control unit 21 temporarily stops the charging operation even if charging is being performed (S120). Then, the processing from S101 is performed. By doing this, for example, a device that is often used in a rechargeable state (that is, a state in which charging is possible because power is supplied to the battery 43), such as a notebook personal computer. In addition, the charging voltage can be changed according to the battery voltage at the start of past charging (including the time when charging is started after stopping charging in S120).

It is a functional block diagram of the charging device concerning embodiment of this invention. It is a figure which shows the time change of the battery voltage concerning embodiment of this invention. It is a flowchart of the process concerning embodiment of this invention. It is a memory table concerning embodiment of this invention. It is a functional block diagram of the charging device concerning embodiment of this invention. It is a flowchart of the process concerning embodiment of this invention. It is a figure which shows the relationship between the time concerning the background art of this invention, an electric current, and a voltage. It is a figure which shows the time change of the battery voltage concerning the background art of this invention. It is a figure which shows the time change of the battery voltage concerning the background art of this invention.

Explanation of symbols

10 charging device, 20, 20a charging unit, 21, 21a charging control unit, 22 determination unit, 23 memory unit, 24 voltage detection unit, 25 constant voltage circuit, 26 constant current circuit, 27 charging voltage control ON / OFF operation unit, 28 current detection unit, 29 electrical resistance, 30 power supply unit, 32 battery charger, 40 battery unit, 41 overcharge overdischarge detection unit, 42 protection circuit, 43 battery, 50 load, 60 AC power supply, 70 power supply control unit, 80, 81, 82, 83 terminals

Claims (5)

In the case where the battery is charged a plurality of times, a ratio relation amount calculation for calculating a ratio relation amount indicating a ratio of the plurality of times when the battery voltage at the start of the battery charging is higher than a predetermined threshold voltage Means,
Charging voltage determining means for determining the charging voltage so that the charging voltage during constant voltage charging differs depending on the magnitude of the calculated proportion relationship amount and the predetermined threshold proportion relationship amount;
Charging means for charging the battery at the determined charging voltage during constant voltage charging;
A charging device comprising: The charging device according to claim 1,
The charging voltage determining means includes
When the calculated proportion relation amount is smaller than the predetermined threshold proportion relation amount, the first charging voltage is determined as the charging voltage at the constant voltage charging, and the auxiliary charging start voltage is set as the first supplement threshold value,
When the calculated proportion relation amount is larger than the predetermined threshold proportion relation amount, the second charging voltage that is lower than the first charging voltage is determined as the charging voltage at the constant voltage charging, and the auxiliary charging is performed. And the second replenishment threshold
The difference between the first replenishment threshold and the second replenishment threshold is determined according to the difference between the first charging voltage and the second charging voltage.
A charging device characterized by that. The charging device according to claim 1 or 2,
The determination of the charging voltage by the charging voltage determination means is performed when the power supply to the battery becomes possible and when the power of the apparatus including the battery as a driving power source is turned on.
A charging device characterized by that. The charging device according to any one of claims 1 to 3,
A charging mode determining means for determining, as a charging mode, either a battery deterioration preventing mode for preventing deterioration of the battery or a battery operating time securing mode for extending the operating time of the battery;
Further including
When the determined charging mode is a battery deterioration prevention mode, the charging voltage determining means determines whether the charging voltage during constant voltage charging is based on the magnitude of the calculated proportion relationship amount and a predetermined threshold proportion relationship amount. Determine the charging voltage to be different,
A charging device characterized by that. In the case where the battery is charged a plurality of times, a ratio relation amount calculation for calculating a ratio relation amount indicating a ratio of the plurality of times when the battery voltage at the start of the battery charging is higher than a predetermined threshold voltage Steps,
A charging voltage determining step for determining the charging voltage so that the charging voltage at the time of constant voltage charging differs depending on the magnitude of the calculated proportion relationship amount and the predetermined threshold proportion relationship amount;
A charging step of charging the battery at the determined charging voltage at the time of constant voltage charging; and
The charging method characterized by including.

Images