US20210305821A1 - Charger circuit with battery protection mechanism - Google Patents

Charger circuit with battery protection mechanism Download PDF

Info

Publication number
US20210305821A1
US20210305821A1 US17/240,779 US202117240779A US2021305821A1 US 20210305821 A1 US20210305821 A1 US 20210305821A1 US 202117240779 A US202117240779 A US 202117240779A US 2021305821 A1 US2021305821 A1 US 2021305821A1
Authority
US
United States
Prior art keywords
battery
battery pack
circuit
over
output terminal
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.)
Pending
Application number
US17/240,779
Inventor
Kuo-Chang Lo
Chia-Hsiang Lin
Chih-Chien Huang
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.)
MediaTek Inc
Original Assignee
MediaTek Inc
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 MediaTek Inc filed Critical MediaTek Inc
Priority to US17/240,779 priority Critical patent/US20210305821A1/en
Assigned to MEDIATEK INC. reassignment MEDIATEK INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: LO, KUO-CHANG, HUANG, CHIH-CHIEN, LIN, CHIA-HSIANG
Publication of US20210305821A1 publication Critical patent/US20210305821A1/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/0026—
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/00308—Overvoltage protection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/18—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for batteries; for accumulators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/00032—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries characterised by data exchange
    • H02J7/00036—Charger exchanging data with battery
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/00047—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with provisions for charging different types of batteries
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/00309—Overheat or overtemperature protection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/0031—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits using battery or load disconnect circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/0036—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits using connection detecting circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0042—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries characterised by the mechanical construction
    • H02J7/0045—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries characterised by the mechanical construction concerning the insertion or the connection of the batteries
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/007—Regulation of charging or discharging current or voltage
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/007—Regulation of charging or discharging current or voltage
    • H02J7/007188—Regulation of charging or discharging current or voltage the charge cycle being controlled or terminated in response to non-electric parameters
    • H02J7/007192—Regulation of charging or discharging current or voltage the charge cycle being controlled or terminated in response to non-electric parameters in response to temperature
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/007—Regulation of charging or discharging current or voltage
    • H02J7/007188—Regulation of charging or discharging current or voltage the charge cycle being controlled or terminated in response to non-electric parameters
    • H02J7/007192—Regulation of charging or discharging current or voltage the charge cycle being controlled or terminated in response to non-electric parameters in response to temperature
    • H02J7/007194—Regulation of charging or discharging current or voltage the charge cycle being controlled or terminated in response to non-electric parameters in response to temperature of the battery
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/00302—Overcharge protection

Definitions

  • the present invention relates generally to battery protection, and more particularly, to a charger circuit and a power system that have over-voltage and over-temperature protection mechanism for a battery pack.
  • Over-temperature, over-current or over-voltage errors of a battery pack may occur when an electronic device that is powered by the battery pack performs a charging/discharging operation on it.
  • the battery pack usually has a built-in protection circuit, which is able to detect the above-mentioned errors and cutting off the charging/discharging current once the temperature of the battery pack, charging/discharging current to/from a battery cell of the battery pack, and/or the voltage level of the battery cell exceeds safe limits.
  • a protection mechanism only resides at the battery side, and does not reside at the system side (i.e., a charger circuit for controlling the charge of the battery pack).
  • a charger circuit for use in controlling charge of a battery pack.
  • the charger circuit has at least one power output terminal and one connection terminal for coupling the battery pack and includes a charge control switch, a discharging circuit and a control unit.
  • the charge control switch is arranged to selectively provide a power from a power source to the battery pack through the power output terminal.
  • the discharging circuit is selectively coupled to the power output terminal, and arranged to discharge a battery cell of the battery pack when being coupled to the power output terminal.
  • the control unit is coupled to the charge control switch and the discharging circuit, and determines whether to turn off the charge control switch and control the discharging circuit to couple to the power output terminal according to at least an over-voltage detection based on a signal based on the connection terminal.
  • a power system comprising a charger circuit and a battery pack including a battery cell.
  • the charger circuit has at least one power output terminal and one connection terminal for coupling the battery pack.
  • the charger circuit comprises a charge control switch, a discharging circuit and a control unit.
  • the charge control switch is arranged to selectively provide a power from a power source to the battery pack through the power output terminal.
  • the discharging circuit is selectively coupled to the power output terminal, and arranged to discharge the battery cell when being coupled to the power output terminal.
  • the control unit is coupled to the charge control switch and the discharging circuit, and arranged to determine whether to turn off the charge control switch and to control the discharging circuit to couple to the power output terminal according to an over-voltage detection based on a signal on the connection terminal.
  • FIGURE illustrates a schematic diagram of a charger circuit with battery protection mechanism and a battery pack according to one embodiment of the present invention.
  • FIGURE illustrates a schematic diagram of a charger circuit with protection mechanism and a battery pack according to one embodiment of the present invention.
  • a charger circuit 100 has a power input terminal 110 , a battery identification terminal 112 , a battery temperature terminal 114 , a power output terminal 116 , and a battery sensing terminal 118 , which are generally physical pins.
  • the charger circuit 100 connects to a battery pack 200 through these terminals.
  • the battery identification terminal 112 is coupled to a battery identification contact 212 of the battery pack 200 through at least one electrical conductor.
  • the battery temperature terminal 114 is coupled to a battery thermistor contact 214 of the battery pack 200 through at least one electrical conductor.
  • the power output terminal 116 and a battery sensing terminal 118 are coupled to a battery power contact 216 of the battery pack 200 through at least one electrical conductor. Additionally, the charger circuit 100 may also communicate with the battery pack 200 via a Mobile Industry Processor Interface (MIDI) battery interface (BIF) formed by one of the battery identification terminal 112 and the battery temperature terminal 114 to monitor electrical characteristics of a battery cell 210 in the battery pack 200 .
  • MIDI Mobile Industry Processor Interface
  • BIF Battery interface
  • the protection mechanism provided by the charger circuit 100 is intended to stop the charge of the battery cell 210 and provide a discharging path to conduct the discharge of the battery cell 210 based on over-voltage detection and/or over-temperature detection.
  • the charger circuit 100 uses a charge control switch 140 (which is preferably a power MOSFET illustrated by FIGURE) to selectively provide electrical power (e.g., the current I BAT ) from a power source 300 to the battery cell 210 through the power output terminal 116 and the battery power contact 216 such that the battery cell 210 can be charged in a constant current or constant voltage mode.
  • a charge control switch 140 which is preferably a power MOSFET illustrated by FIGURE
  • control unit 120 will turn off the charge control switch 140 to stop the charge of the battery pack 200 or do not start the charge of the battery pack 200 (if the battery pack 200 is currently being discharged) and also couple a discharging circuit 150 to the power output terminal 116 to provide the discharging path for discharging the battery cell 210 .
  • the control unit 120 may monitor a voltage level on the battery identification terminal 112 . If the voltage level on the battery identification terminal 112 matches a predefined level transition pattern such as a pull-down signal or a pull-high signal lasting for a certain period, the control unit 120 determines the battery cell 210 is in over-voltage condition.
  • the batter pack 200 comprises a detection circuit 220 .
  • the detection circuit 220 comprises a comparing device 222 and a resistive circuit 224 .
  • the comparing device 222 has two input terminals, one of which is connected to a positive electrode of the battery cell 210 , while the other is connected to a reference voltage level V REF .
  • the comparing device 222 detects a voltage level V_POS at the positive electrode V_POS is higher than or lower than the reference voltage level V REF , it outputs a driving current to pass through the resistive circuit 224 , thereby pulling down/or pulling up the voltage level on the battery identification terminal 112 and the battery identification contact 212 for a certain period, so as to generate an over-voltage detection signal.
  • the control unit 120 can be aware of the over-voltage condition, and accordingly controls the charge control switch 140 to turn off, and further controls the discharging circuit 150 to couple to the power output terminal 116 , thereby discharging the battery cell 210 .
  • the resistive circuit 224 could be preferably implemented with an identification resistor R ID of the battery pack 200 , which is generally used for facilitating identification of type and electrical characteristics of the battery pack 200 . Only if the charger circuit 100 reads the resistance of the resistive circuit 224 has a value within a predetermined range, the charge of the battery cell 210 is allowed. To make the control unit 120 differentiate an identification signal (for determining the resistance) from an over-voltage detection signal, the comparing circuit 222 could be designed to provide the driving current for realizing the predefined level transition pattern that is different from the pattern of the identification signal. For example, if the identification signal remains at 1V for 200 ms, the over-voltage detection signal could remain at 2V for 500 ms.
  • the comparing device 222 and the resistive circuit 226 could also generate the over-voltage detection signal.
  • the comparing device 222 detects the voltage level V_POS at the positive electrode of the battery cell 210 is higher than or lower than the reference voltage level V REF , it outputs the driving current to pass through the resistive circuit 226 , thereby pulling down or pulling up the voltage level on the battery temperature terminal 114 and the battery temperature contact 214 , thereby generating the over-voltage detection signal.
  • the resistive circuit 226 could be a negative temperature coefficient (NTC) thermistor R NTC of the battery pack 200 , which is generally used to sense the temperature in the inside of the battery pack 200 .
  • NTC negative temperature coefficient
  • the resistive circuit 226 is able to pull down the voltage level on the battery temperature terminal 114 and the battery temperature contact 214 to generate an over-temperature detection signal.
  • the control unit 120 could stop charging and accordingly provide the discharging path to the battery pack 200 when one of the over-voltage condition and the over-temperature condition occurs.
  • the battery pack 200 is a smart battery, and supports digital data communication protocol, such as MIPI BIF. Then, one of the battery identification terminal 112 and the battery temperature terminal 114 could be served as a battery communication line (BCL) of MIPI BIF. In this case, a BIF module 170 of the charger circuit 100 could communicate with the BIF module 230 of the battery pack 200 to obtain electrical characteristics, such as a voltage level and/or a temperature of the battery cell 210 .
  • BCL battery communication line
  • the control unit 120 could obtain information about the voltage level or the temperature of the battery cell 210 through the BIL module 170 , and determines whether to turn off the charge control switch 120 to stop the charge of the battery pack 200 and whether to control the discharging circuit 150 to couple to the power output terminal 116 for discharging battery pack 200 .
  • a voltage sensing circuit 160 coupled to the battery sensing terminal 118 can also detect the over-voltage condition.
  • the over-voltage condition can be detected by measuring a voltage level at the battery power terminal 216 .
  • the control unit 120 Once the control unit 120 is aware that the voltage level measured at the battery power terminal 216 is higher than or lower than a predefined threshold (e.g. the reference voltage level V REF ), the control unit 120 turns off the charge control switch 120 and controls the discharging circuit 150 to couple to the power output terminal 116 for discharging.
  • a predefined threshold e.g. the reference voltage level V REF
  • the discharging circuit 150 may comprise a current source 152 to provide a sink current in a direction to a low voltage level, thereby discharging the battery cell 210 of the battery pack 200 .
  • a current source 152 to provide a sink current in a direction to a low voltage level, thereby discharging the battery cell 210 of the battery pack 200 .
  • one terminal of the current source 152 is connected to a ground, while the other terminal is coupled to the power output terminal 116 through a switch controlled by the control unit 120 .
  • the illustrated embodiment is not intended to limit the present invention in scope. According to various embodiments of the present invention, the discharging circuit 150 could be implemented with different architecture.
  • the present invention provides a battery protection mechanism residing in the charger circuit/system side for prevent against the damage caused by over-voltage and/or over-temperature conditions of the battery pack.
  • An important advantage of the present invention is that the battery protection mechanism is still valid even if the protection circuit in the battery pack has malfunctioned. As a result, the safety of battery use can be fully guaranteed.

Abstract

A charger circuit for use in controlling charge of a battery pack, which includes a charge control switch, a discharging circuit and a control unit. The charger circuit has at least one power output terminal and one connection terminal for coupling the battery pack. The charge control switch is arranged to selectively provide a power from a power source to the battery pack through the power output terminal. The discharging circuit is selectively coupled to the power output terminal, and arranged to discharge a battery cell of the battery pack when being coupled to the power output terminal. The control unit is coupled to the charge control switch and the discharging circuit, and determines whether to turn off the charge control switch and control the discharging circuit to couple to the power output terminal according to at least an over-voltage detection based on a signal based on the connection terminal.

Description

    CROSS REFERENCE TO RELATED APPLICATIONS
  • This application claims the benefit of U.S. Provisional Application No. 62/316,582, filed on Apr. 1, 2016. The entire contents of the related applications are incorporated herein by reference.
    • BACKGROUND
  • The present invention relates generally to battery protection, and more particularly, to a charger circuit and a power system that have over-voltage and over-temperature protection mechanism for a battery pack.
  • Over-temperature, over-current or over-voltage errors of a battery pack, such as a Li-ion and Li-Polymer battery pack, may occur when an electronic device that is powered by the battery pack performs a charging/discharging operation on it. To prevent such errors from causing damage, the battery pack usually has a built-in protection circuit, which is able to detect the above-mentioned errors and cutting off the charging/discharging current once the temperature of the battery pack, charging/discharging current to/from a battery cell of the battery pack, and/or the voltage level of the battery cell exceeds safe limits. However, such protection mechanism only resides at the battery side, and does not reside at the system side (i.e., a charger circuit for controlling the charge of the battery pack). Hence, when over-temperature, over-current or over-voltage errors occurs during charging period but the protection circuit in the battery pack has malfunctioned, power supplied by the charger circuit may continue the charge of the battery cell, which eventually causes unrecoverable and severely damages to ruin the battery pack, or even exploding the battery back.
    • SUMMARY
  • To address the above-mentioned problems, it is one object of the present invention to provide a charger circuit and a power system that have battery protection mechanism, which is capable of stopping a charging operation on a battery and also providing a discharging path for discharging the battery upon detecting an over-voltage/over-temperature condition.
  • According to one embodiment of the present invention, a charger circuit for use in controlling charge of a battery pack is provided. The charger circuit has at least one power output terminal and one connection terminal for coupling the battery pack and includes a charge control switch, a discharging circuit and a control unit. The charge control switch is arranged to selectively provide a power from a power source to the battery pack through the power output terminal. The discharging circuit is selectively coupled to the power output terminal, and arranged to discharge a battery cell of the battery pack when being coupled to the power output terminal. The control unit is coupled to the charge control switch and the discharging circuit, and determines whether to turn off the charge control switch and control the discharging circuit to couple to the power output terminal according to at least an over-voltage detection based on a signal based on the connection terminal.
  • According to one embodiment of the present invention, a power system is provided. The power system comprises a charger circuit and a battery pack including a battery cell. The charger circuit has at least one power output terminal and one connection terminal for coupling the battery pack. Additionally, the charger circuit comprises a charge control switch, a discharging circuit and a control unit. The charge control switch is arranged to selectively provide a power from a power source to the battery pack through the power output terminal. The discharging circuit is selectively coupled to the power output terminal, and arranged to discharge the battery cell when being coupled to the power output terminal. The control unit is coupled to the charge control switch and the discharging circuit, and arranged to determine whether to turn off the charge control switch and to control the discharging circuit to couple to the power output terminal according to an over-voltage detection based on a signal on the connection terminal.
  • These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various FIGURES and drawings.
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIGURE illustrates a schematic diagram of a charger circuit with battery protection mechanism and a battery pack according to one embodiment of the present invention.
    •  DETAILED DESCRIPTION
  • Certain terms are used throughout the following descriptions and claims to refer to particular system components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not differ in function. In the following discussion and in the claims, the terms “include”, “including”, “comprise”, and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ” The terms “couple” and “coupled” are intended to mean either an indirect or a direct electrical connection. Thus, if a first device couples to a second device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections.
  • FIGURE illustrates a schematic diagram of a charger circuit with protection mechanism and a battery pack according to one embodiment of the present invention. As illustrated, a charger circuit 100 has a power input terminal 110, a battery identification terminal 112, a battery temperature terminal 114, a power output terminal 116, and a battery sensing terminal 118, which are generally physical pins. The charger circuit 100 connects to a battery pack 200 through these terminals. The battery identification terminal 112 is coupled to a battery identification contact 212 of the battery pack 200 through at least one electrical conductor. The battery temperature terminal 114 is coupled to a battery thermistor contact 214 of the battery pack 200 through at least one electrical conductor. The power output terminal 116 and a battery sensing terminal 118 are coupled to a battery power contact 216 of the battery pack 200 through at least one electrical conductor. Additionally, the charger circuit 100 may also communicate with the battery pack 200 via a Mobile Industry Processor Interface (MIDI) battery interface (BIF) formed by one of the battery identification terminal 112 and the battery temperature terminal 114 to monitor electrical characteristics of a battery cell 210 in the battery pack 200.
  • The protection mechanism provided by the charger circuit 100 is intended to stop the charge of the battery cell 210 and provide a discharging path to conduct the discharge of the battery cell 210 based on over-voltage detection and/or over-temperature detection. Typically, the charger circuit 100 uses a charge control switch 140 (which is preferably a power MOSFET illustrated by FIGURE) to selectively provide electrical power (e.g., the current IBAT) from a power source 300 to the battery cell 210 through the power output terminal 116 and the battery power contact 216 such that the battery cell 210 can be charged in a constant current or constant voltage mode. In the present invention, once a control unit 120 detects that the battery cell 210 is in the over-voltage condition or the battery cell 210/battery pack 200 is in the over-temperature condition, the control unit 120 will turn off the charge control switch 140 to stop the charge of the battery pack 200 or do not start the charge of the battery pack 200 (if the battery pack 200 is currently being discharged) and also couple a discharging circuit 150 to the power output terminal 116 to provide the discharging path for discharging the battery cell 210.
  • In the embodiments of the present invention, there are several approaches to perform the over-voltage detection. The control unit 120 may monitor a voltage level on the battery identification terminal 112. If the voltage level on the battery identification terminal 112 matches a predefined level transition pattern such as a pull-down signal or a pull-high signal lasting for a certain period, the control unit 120 determines the battery cell 210 is in over-voltage condition. In the case, the batter pack 200 comprises a detection circuit 220. The detection circuit 220 comprises a comparing device 222 and a resistive circuit 224. The comparing device 222 has two input terminals, one of which is connected to a positive electrode of the battery cell 210, while the other is connected to a reference voltage level VREF. Once the comparing device 222 detects a voltage level V_POS at the positive electrode V_POS is higher than or lower than the reference voltage level VREF, it outputs a driving current to pass through the resistive circuit 224, thereby pulling down/or pulling up the voltage level on the battery identification terminal 112 and the battery identification contact 212 for a certain period, so as to generate an over-voltage detection signal. As a result, the control unit 120 can be aware of the over-voltage condition, and accordingly controls the charge control switch 140 to turn off, and further controls the discharging circuit 150 to couple to the power output terminal 116, thereby discharging the battery cell 210. The resistive circuit 224 could be preferably implemented with an identification resistor RID of the battery pack 200, which is generally used for facilitating identification of type and electrical characteristics of the battery pack 200. Only if the charger circuit 100 reads the resistance of the resistive circuit 224 has a value within a predetermined range, the charge of the battery cell 210 is allowed. To make the control unit 120 differentiate an identification signal (for determining the resistance) from an over-voltage detection signal, the comparing circuit 222 could be designed to provide the driving current for realizing the predefined level transition pattern that is different from the pattern of the identification signal. For example, if the identification signal remains at 1V for 200 ms, the over-voltage detection signal could remain at 2V for 500 ms.
  • Alternatively, the comparing device 222 and the resistive circuit 226 could also generate the over-voltage detection signal. Similarly, when the comparing device 222 detects the voltage level V_POS at the positive electrode of the battery cell 210 is higher than or lower than the reference voltage level VREF, it outputs the driving current to pass through the resistive circuit 226, thereby pulling down or pulling up the voltage level on the battery temperature terminal 114 and the battery temperature contact 214, thereby generating the over-voltage detection signal. The resistive circuit 226 could be a negative temperature coefficient (NTC) thermistor RNTC of the battery pack 200, which is generally used to sense the temperature in the inside of the battery pack 200. Typically, when the temperature in the inside of the battery pack 200 exceeds safe limits, the resistive circuit 226 is able to pull down the voltage level on the battery temperature terminal 114 and the battery temperature contact 214 to generate an over-temperature detection signal. Hence, through the signal on the battery temperature terminal 114, the control unit 120 could stop charging and accordingly provide the discharging path to the battery pack 200 when one of the over-voltage condition and the over-temperature condition occurs.
  • If the battery pack 200 is a smart battery, and supports digital data communication protocol, such as MIPI BIF. Then, one of the battery identification terminal 112 and the battery temperature terminal 114 could be served as a battery communication line (BCL) of MIPI BIF. In this case, a BIF module 170 of the charger circuit 100 could communicate with the BIF module 230 of the battery pack 200 to obtain electrical characteristics, such as a voltage level and/or a temperature of the battery cell 210. The control unit 120 could obtain information about the voltage level or the temperature of the battery cell 210 through the BIL module 170, and determines whether to turn off the charge control switch 120 to stop the charge of the battery pack 200 and whether to control the discharging circuit 150 to couple to the power output terminal 116 for discharging battery pack 200.
  • Additionally, a voltage sensing circuit 160 coupled to the battery sensing terminal 118 can also detect the over-voltage condition. As the battery sensing terminal 118 is coupled to the battery power contact 216 of the battery pack 200, and the battery power terminal 216 is further coupled to a positive electrode of the battery cell 210, the over-voltage condition can be detected by measuring a voltage level at the battery power terminal 216. Once the control unit 120 is aware that the voltage level measured at the battery power terminal 216 is higher than or lower than a predefined threshold (e.g. the reference voltage level VREF), the control unit 120 turns off the charge control switch 120 and controls the discharging circuit 150 to couple to the power output terminal 116 for discharging.
  • In one embodiment, the discharging circuit 150 may comprise a current source 152 to provide a sink current in a direction to a low voltage level, thereby discharging the battery cell 210 of the battery pack 200. In the embodiment illustrated in FIGURE, one terminal of the current source 152 is connected to a ground, while the other terminal is coupled to the power output terminal 116 through a switch controlled by the control unit 120. However, the illustrated embodiment is not intended to limit the present invention in scope. According to various embodiments of the present invention, the discharging circuit 150 could be implemented with different architecture.
  • In conclusion, the present invention provides a battery protection mechanism residing in the charger circuit/system side for prevent against the damage caused by over-voltage and/or over-temperature conditions of the battery pack. An important advantage of the present invention is that the battery protection mechanism is still valid even if the protection circuit in the battery pack has malfunctioned. As a result, the safety of battery use can be fully guaranteed.
  • Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least an implementation. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. Thus, although embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that claimed subject matter may not be limited to the specific features or acts described. Rather, the specific features and acts are disclosed as sample forms of implementing the claimed subject matter.
  • Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.

Claims (20)

1-15. (canceled)
16. A charger circuit for use in controlling charge of a battery pack, the charger circuit comprising:
at least one power output terminal and at least one connection terminal for coupling to the battery pack;
a charge control switch, arranged to selectively provide power from a power source to the battery pack through the power output terminal;
a discharging circuit comprising a switch and a current source; and
a control unit, coupled to the charge control switch, the at least one connection terminal, and the discharging circuit, wherein:
the discharging circuit is selectively coupled by the switch to the at least one power output terminal and configured to discharge a battery cell of the battery pack when coupled to the at least one power output terminal,
the control unit is configured to determine whether to control the discharging circuit to couple to the at least one power output terminal according to the signal on the at least one connection terminal, and
the signal from the battery pack on the at least one connection terminal indicates an over-voltage condition.
17. The charger circuit of claim 16, wherein a connection terminal of the at least one connection terminal is coupled to a battery power contact of the battery pack,
the charger circuit further comprises a voltage sensing circuit arranged to measure a voltage level on the battery power contact to generate an over-voltage detection signal, and
the control unit is configured to open the charge control switch and to control the discharging circuit to couple to the at least one power output terminal if the over-voltage detection signal indicates the over-voltage condition.
18. The charger circuit of claim 16, wherein a connection terminal of the at least one connection terminal is coupled to a battery identification contact of the battery pack,
the battery pack comprises a detection circuit arranged to generate an over-voltage detection signal at the battery identification contact by detecting whether a voltage level of a positive electrode of a battery cell of the battery pack is higher than a predetermined reference voltage level, and
the control unit is configured to open the charge control switch and to control the discharging circuit to couple to the at least one power output terminal if the over-voltage detection signal indicates the over-voltage condition.
19. The charger circuit of claim 16, wherein the signal on the at least one connection terminal is further arranged to indicate an over-temperature condition.
20. The charger circuit of claim 19, wherein a connection terminal of the at least one connection terminal is coupled to a battery temperature contact of the battery pack, and
the battery pack comprises a detection circuit that is arranged to generate an over-temperature detection signal at the battery temperature contact by detecting whether a temperature of the battery pack is higher than a predetermined value, and
the control unit is arranged to open the charge control switch and control the discharging circuit to couple to the at least one power output terminal if the over-temperature detection signal indicates the over-temperature condition.
21. The charger circuit of claim 16, wherein the current source of the discharging circuit is connected to a voltage reference level, and
when the discharging circuit is coupled to the at least one power output terminal through the switch, the discharging circuit provides a current path from the battery cell through the at least one power output terminal to the reference level.
22. The charger circuit of claim 16, wherein the at least one connection terminal is arranged to function as a battery communication line (BCL) of a Mobile Industry Processor Interface (MIPI) battery interface (BIF), and the charger circuit further comprises a BIF module,
the control unit is configured to obtain information regarding a voltage level of the battery cell from the BCL module,
the control unit is further configured to determine whether to open the charge control switch and to control the discharging circuit to couple to the power output terminal if the information from the BCL module indicates the over-voltage condition, and
the BIF module of the charger circuit is coupled to the BIF module of the battery pack through the BCL.
23. The charger circuit of claim 16, wherein the charge control switch comprises a power MOSFET.
24. A power system comprising a battery protection mechanism, the power system comprising:
a battery pack comprising a battery cell; and
a charger circuit, comprising:
at least one power output terminal and at least one connection terminal for coupling to the battery pack;
a charge control switch, arranged to selectively provide power from a power source to the battery pack through the power output terminal;
a discharging circuit comprising a switch and a current source; and
a control unit, coupled to the charge control switch, the at least one connection terminal, and the discharging circuit, wherein:
the discharging circuit is selectively coupled by the switch to the at least one power output terminal and configured to discharge a battery cell of the battery pack when coupled to the at least one power output terminal,
the control unit is configured to determine whether to control the discharging circuit to couple to the at least one power output terminal according to the signal on the at least one connection terminal, and
the signal from the battery pack on the at least one connection terminal indicates an over-voltage condition.
25. The power system of claim 24, wherein a connection terminal of the at least one connection terminal is coupled to a battery power contact of the battery pack,
the charger circuit further comprises a voltage sensing circuit arranged to measure a voltage level on the battery power contact to generate an over-voltage detection signal, and
the control unit is configured to open the charge control switch and to control the discharging circuit to couple to the at least one power output terminal if the over-voltage detection signal indicates the over-voltage condition.
26. The power system of claim 24, wherein a connection terminal of the at least one connection terminal is coupled to a battery identification contact of the battery pack,
the battery pack comprises a detection circuit arranged to generate an over-voltage detection signal at the battery identification contact by detecting whether a voltage level of a positive electrode of a battery cell of the battery pack is higher than a predetermined reference voltage level, and
the control unit is configured to open the charge control switch and to control the discharging circuit to couple to the at least one power output terminal if the over-voltage detection signal indicates the over-voltage condition.
27. The power system of claim 24, wherein the signal on the at least one connection terminal is further arranged to indicate an over-temperature condition.
28. The charger circuit of claim 27, wherein a connection terminal of the at least one connection terminal is coupled to a battery temperature contact of the battery pack, and
the battery pack comprises a detection circuit that is arranged to generate an over-temperature detection signal at the battery temperature contact by detecting whether a temperature of the battery pack is higher than a predetermined value, and
the control unit is arranged to open the charge control switch and control the discharging circuit to couple to the at least one power output terminal if the over-temperature detection signal indicates the over-temperature condition.
29. The power system of claim 24, wherein the current source of the discharging circuit is connected to a voltage reference level, and
when the discharging circuit is coupled to the at least one power output terminal through the switch, the discharging circuit provides a current path from the battery cell through the at least one power output terminal to the reference level.
30. The power system of claim 24, wherein the at least one connection terminal is arranged to function as a battery communication line (BCL) of a Mobile Industry Processor Interface (MIPI) battery interface (BIF), and the charger circuit further comprises a BIF module,
the control unit is configured to obtain information regarding a voltage level of the battery cell from the BCL module,
the control unit is further configured to determine whether to open the charge control switch and to control the discharging circuit to couple to the power output terminal if the information from the BCL module indicates the over-voltage condition, and
the BIF module of the charger circuit is coupled to the BIF module of the battery pack through the BCL.
31. The power system of claim 24, wherein battery pack further comprises:
a comparing device, having a first input terminal and a second input terminal, the first input terminal being coupled to a positive electrode of the battery cell and the second input terminal being coupled to a reference voltage level, the comparing device configured to compare a voltage level on the positive electrode of the battery cell with the reference voltage level and generate a driving current when the voltage level on the positive electrode of the battery cell is higher than the reference voltage level; and
a resistive circuit, coupled to an output terminal of the comparing device, arranged to generate an over-voltage detection signal when the driving current passes therethrough.
32. The power system of claim 31, wherein the connection terminal of the charger circuit is coupled to a battery identification contact of the battery pack, and the resistive circuit comprises an identification resistor.
33. The power system of claim 31, wherein the connection terminal of the charger circuit is coupled to a battery temperature contact of the battery pack, and the resistive circuit comprises a negative temperature coefficient thermistor.
34. The power system of claim 24, wherein the charge control switch comprises a power MOSFET.
US17/240,779 2016-04-01 2021-04-26 Charger circuit with battery protection mechanism Pending US20210305821A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US17/240,779 US20210305821A1 (en) 2016-04-01 2021-04-26 Charger circuit with battery protection mechanism

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US201662316582P 2016-04-01 2016-04-01
US15/172,165 US11038358B2 (en) 2016-04-01 2016-06-03 Charger circuit with battery protection mechanism
US17/240,779 US20210305821A1 (en) 2016-04-01 2021-04-26 Charger circuit with battery protection mechanism

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US15/172,165 Continuation US11038358B2 (en) 2016-04-01 2016-06-03 Charger circuit with battery protection mechanism

Publications (1)

Publication Number Publication Date
US20210305821A1 true US20210305821A1 (en) 2021-09-30

Family

ID=57749762

Family Applications (2)

Application Number Title Priority Date Filing Date
US15/172,165 Active 2037-09-24 US11038358B2 (en) 2016-04-01 2016-06-03 Charger circuit with battery protection mechanism
US17/240,779 Pending US20210305821A1 (en) 2016-04-01 2021-04-26 Charger circuit with battery protection mechanism

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US15/172,165 Active 2037-09-24 US11038358B2 (en) 2016-04-01 2016-06-03 Charger circuit with battery protection mechanism

Country Status (4)

Country Link
US (2) US11038358B2 (en)
EP (1) EP3226375B1 (en)
CN (1) CN107276136B (en)
TW (1) TWI628894B (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11038358B2 (en) * 2016-04-01 2021-06-15 Mediatek Inc. Charger circuit with battery protection mechanism
CN107681730A (en) * 2017-10-26 2018-02-09 珠海市魅族科技有限公司 A kind of battery, terminal device, charging system, the recognition methods of battery and device
GB2563311B (en) * 2018-03-08 2020-03-04 O2Micro Inc Circuits, systems and methods for protecting batteries
KR102432368B1 (en) * 2020-08-31 2022-08-11 삼성에스디아이 주식회사 Battery protection circuit and battery apparatus comprising the same
TWI763242B (en) * 2021-01-08 2022-05-01 和碩聯合科技股份有限公司 Power supply circuit and power distribution method thereof

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5896025A (en) * 1995-12-27 1999-04-20 Hitachi Maxell, Ltd. Secondary battery protection device from overcharge/overdischarge
US20030178968A1 (en) * 2002-03-25 2003-09-25 Kazuyuki Sakakibara Apparatus for refreshing batteries
US20080054852A1 (en) * 2006-08-31 2008-03-06 Kabushiki Kaisha Toshiba Charging system and charging method
US20080122400A1 (en) * 2006-11-27 2008-05-29 Matsushita Electric Works Ltd. Charger
US20080310064A1 (en) * 2007-06-13 2008-12-18 Sanyo Electric Co., Ltd. Protection Circuit
US20090212736A1 (en) * 2008-02-22 2009-08-27 Access Business Group International Llc Inductive power supply system with battery type detection
US20130027828A1 (en) * 2010-04-21 2013-01-31 Makita Corporation Internal temperature estimation unit for battery for electric power tool, and apparatus for electric power tool
US20130111251A1 (en) * 2010-06-11 2013-05-02 Nokia Corporation Method for battery removal detection
US20140035360A1 (en) * 2011-01-05 2014-02-06 Samsung Sdi Co., Ltd. Battery with Autonomous Cell Balancing
US20160097820A1 (en) * 2014-10-02 2016-04-07 Dell Products L.P. Battery Performance Under high Temperature Exposure
US20170268449A1 (en) * 2014-08-25 2017-09-21 Hitachi Automotive Systems, Ltd. Diagnosis of boost capacitor using discharge circuit
US11038358B2 (en) * 2016-04-01 2021-06-15 Mediatek Inc. Charger circuit with battery protection mechanism

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6160381A (en) 1998-05-21 2000-12-12 Qualcomm Inc. Battery pack protection circuit and battery pack including a protection circuit
JP3380766B2 (en) 1999-03-18 2003-02-24 富士通株式会社 Protection method, control circuit, and battery unit
EP1128517A3 (en) 2000-02-24 2003-12-10 Makita Corporation Adapters for rechargeable battery packs
JP3860035B2 (en) 2000-04-13 2006-12-20 株式会社マキタ Adapter for charging device
CN101916887B (en) * 2003-10-14 2013-03-20 布莱克和戴克公司 Battery pack
US7518341B2 (en) 2004-12-23 2009-04-14 Dell Product L.P. Method for verifying smart battery failures by measuring input charging voltage and associated systems
JP4943296B2 (en) 2007-10-30 2012-05-30 ソニー株式会社 Battery pack, secondary battery charging method, and charging device
JP2011076949A (en) * 2009-09-30 2011-04-14 Toshiba Corp Information processing apparatus
JP5582397B2 (en) 2010-08-31 2014-09-03 日立工機株式会社 Electric tool and battery pack used for electric tool
CN202602326U (en) 2012-05-09 2012-12-12 杭州勇华车业有限公司 Charger with over-voltage protection
CN203166483U (en) 2013-01-31 2013-08-28 深圳华粤宝电池有限公司 Lithium ion battery over-temperature protection system
CN104426143B (en) 2013-08-30 2018-04-06 深圳市海洋王照明工程有限公司 Battery overpressure absorbing circuit

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5896025A (en) * 1995-12-27 1999-04-20 Hitachi Maxell, Ltd. Secondary battery protection device from overcharge/overdischarge
US20030178968A1 (en) * 2002-03-25 2003-09-25 Kazuyuki Sakakibara Apparatus for refreshing batteries
US20080054852A1 (en) * 2006-08-31 2008-03-06 Kabushiki Kaisha Toshiba Charging system and charging method
US20080122400A1 (en) * 2006-11-27 2008-05-29 Matsushita Electric Works Ltd. Charger
US20080310064A1 (en) * 2007-06-13 2008-12-18 Sanyo Electric Co., Ltd. Protection Circuit
US20090212736A1 (en) * 2008-02-22 2009-08-27 Access Business Group International Llc Inductive power supply system with battery type detection
US20130027828A1 (en) * 2010-04-21 2013-01-31 Makita Corporation Internal temperature estimation unit for battery for electric power tool, and apparatus for electric power tool
US20130111251A1 (en) * 2010-06-11 2013-05-02 Nokia Corporation Method for battery removal detection
US20140035360A1 (en) * 2011-01-05 2014-02-06 Samsung Sdi Co., Ltd. Battery with Autonomous Cell Balancing
US20170268449A1 (en) * 2014-08-25 2017-09-21 Hitachi Automotive Systems, Ltd. Diagnosis of boost capacitor using discharge circuit
US20160097820A1 (en) * 2014-10-02 2016-04-07 Dell Products L.P. Battery Performance Under high Temperature Exposure
US11038358B2 (en) * 2016-04-01 2021-06-15 Mediatek Inc. Charger circuit with battery protection mechanism

Also Published As

Publication number Publication date
CN107276136A (en) 2017-10-20
EP3226375A1 (en) 2017-10-04
EP3226375B1 (en) 2018-12-05
US20170288427A1 (en) 2017-10-05
CN107276136B (en) 2021-02-26
TWI628894B (en) 2018-07-01
US11038358B2 (en) 2021-06-15
TW201737585A (en) 2017-10-16

Similar Documents

Publication Publication Date Title
US20210305821A1 (en) Charger circuit with battery protection mechanism
KR100987606B1 (en) Apparatus and method for correcting measurements of remaining capacity of battery pack
US8203312B2 (en) Battery pack and control method
US6804100B2 (en) Method and apparatus for protection of batteries
US8970165B2 (en) Determination circuit
TWI396357B (en) Charge system and method for managing voltage storing in cell
EP3036819B1 (en) Method and apparatus for adjusting voltage threshold for battery by measuring internal resistance of battery, and corresponding method and sensor circuit for measuring internal resistance of battery
US8847552B2 (en) Battery pack and method of controlling the same
US7443155B2 (en) Voltage detecting apparatus
US9476778B2 (en) Rechargeable battery temperature detection method, power management device and electronic system
US20170346314A1 (en) Battery protection board, battery and mobile terminal
US11742686B2 (en) Battery device and battery charging system
US20120094154A1 (en) Battery systems with battery gauge functions
US20160190836A1 (en) Method and apparatus for detecting voltage
KR20220015790A (en) Battery management apparatus, battery pack, energy storage system, and battery management method
WO2017201735A1 (en) Battery protecting board, battery, and mobile terminal
KR101245274B1 (en) Battery for hand-held electronic device capable of precharging, Batter charging apparatus, and Method thereof
US11531044B2 (en) Battery pack, battery management system, and method therefor
JP7285963B2 (en) Battery management device and method
JP5663156B2 (en) Secondary battery charge control circuit
JP7357127B2 (en) Smart battery device and its quick charging method
JP6707442B2 (en) Storage battery pack
JP3241659B2 (en) Power supply identification device and power supply identification method
US20230148678A1 (en) Electrical System for an Aerosol Generating Device
JP2017017806A (en) Protection circuit and battery pack

Legal Events

Date Code Title Description
AS Assignment

Owner name: MEDIATEK INC., TAIWAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LO, KUO-CHANG;LIN, CHIA-HSIANG;HUANG, CHIH-CHIEN;SIGNING DATES FROM 20160526 TO 20160529;REEL/FRAME:056044/0144

STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED