Abstract: Lower order control devices control plural battery cells configuring plural battery modules. An input terminal of the low order control device in the highest potential, an output terminal of the low order control device in the lowest potential, and a high order control device are connected by isolating units, photocouplers. Diodes which prevent a discharge current of the battery cells in the battery modules are disposed between the output terminal of the low order control device and the battery cells in the battery module on the low potential side. Terminals related to input/output of a signal are electrically connected without isolating among the plural low order control devices.

Abstract: A charger for a lithium ion secondary battery includes a series circuit of a reverse-current preventive switch, a charging switch and a current-detecting resistor, connected between the battery and the ground a charging control circuit controlling the reverse-current preventive switch and the charging switch, so as to make the battery repeat charging and opening at regular intervals, and so as to detect voltage difference between the specified voltage and the open circuit voltage of the battery during the opening; and a constant-current/constant-voltage control circuit commanding constant-current charging at a first set voltage set relatively high in a range not exceeding the upper limit voltage of the battery, so far as the voltage difference does not exceed a predetermined change-over voltage difference, and commanding constant-voltage charging at a second set voltage, which is lowered from the first set voltage, when the voltage difference becomes smaller than the change-over voltage difference.

Abstract: The present disclosure provides a battery charging control circuit. The charging control circuit includes: a constant-current charging unit and a trickle charging unit. The charging control circuit further includes a branch switch, a control unit, and a detection unit. The branch switch is connected between a power source and the rechargeable battery for enabling or disabling the constant-current charging unit. The control unit is between the constant-current charging unit and the branch switch for controlling the branch switch. The detection unit is used to detect a state of the rechargeable battery. If the detection unit detects the state of the rechargeable battery is correspond to a predetermined state, then the control unit controls the branch switch to disable the constant-current charging unit and enable the trickle charging unit.

Abstract: Embodiments of apparatus and methods for charging a battery are disclosed. The apparatus may comprise a connector configured to electrically couple to a battery, an adjustable current source capable of supplying current to the connector at a plurality of charge rates, and a resistor network configured to bias the adjustable current source to supply current at one of the plurality of charge rates in response to a digital input signal. The method may comprise receiving a digital input signal having a plurality of bits, the digital input signal indicating a desired charge rate for the battery, configuring a resistor network in response to the digital input signal, biasing an adjustable current source using the configured resistor network, and supplying current to the battery at the desired charge rate using the adjustable current source.

Abstract: A charger that charges a battery unit including a secondary battery, includes a receiving unit, a detection unit, a determination unit, and a control unit. The receiving unit receives, from the battery unit, battery state information indicating a state of the battery unit, if the secondary battery is being charged. The detection unit detects charge state information indicating the state of the battery unit, if the secondary battery is being charged. The determination unit determines, using the battery state information and the charge state information, whether the battery unit is in a normal state. The control unit controls charging of the secondary battery in the battery unit depending on whether the battery unit is in the normal state.

Abstract: An electric circuit for supplying power to a DC application is disclosed. The electric circuit comprises a DC power source (1) connectable to an alternator charging circuit (2), an FET (T7), and a capacitor (8) connected across the gate terminal and the source terminal of the FET (T7). The drain terminal of the FET (T7) is connected to a negative terminal of the DC source (1). The FET (T7) protects the circuit against accidental connection of the alternator charging circuit (2) to the DC power source (1) with reversed polarity, by opening a switch (6) of the FET (T7) when this occurs. The capacitor (8) protects the FET (T7) from being pushed into avalanche in case a load-dump transient occurs. This is because the capacitor (8) in this case will charge and discharge, thereby introducing a time delay before the switch (6) is opened. Protection against load-dump transients is thereby obtained by means of a small component with low energy dissipation.

Abstract: A rechargeable multipurpose power management system has a power management system that can include a plurality of power management units. The power management units sources can be individually activated and deactivated (I think there might be a confusion between power sources and the system. Everything is within one box itself (the image that I sent you). Each unit is a power management system that can be connected to a variety of INPUT power sources. Several power management units can be combined together to create a stack of them but each one can operated individually as well). and each one is configured to be coupled to a variety of inputs. A rechargeable battery is coupled to the (One rechargeable battery is attached to only one power management units). A charging controller provides regulated charging to the battery. A plurality of convertors are (do we need to specify here what kind of converters, like DC-DC converters) coupled to the battery and provide output voltages that are accessible individually.

Abstract: A challenge to be met by an aspect of the present invention is to provide a charge control circuit that prevents occurrence of a decrease in battery capacity even when a battery stays in a connection with an external power supply and that induces neither battery deterioration nor overcharge. A first switch (2) is connected to a point among an external power supply (60), a load (80), and a secondary battery (70). When the secondary battery (70) is charged with the external power supply (60), the first switch (2) is turned on. When the secondary battery (70) has accomplished full charge, the first switch 82) is turned off. Electric discharge from the secondary battery (70) to the load (80) is shut off at full charge of the secondary battery (70), so that a load current fed from the secondary battery (70) does not flow and, hence, a decrease in battery capacity of the secondary battery (70) which would be caused by the load (80) does not take place.

Abstract: The battery charging apparatus is made with small and low-cost components. It includes a first transistor (T1) with a control input through which the charging current flows into a battery (B) and a current source (T3, T4, R1, R2) for a control current flowing to the control input of the first transistor. The current source sets or adjusts the control current so that the first transistor is non-conducting or blocked and the charging current flowing into the battery is shut off when a predetermined maximum charging voltage is reached at the battery.

Abstract: A power management unit (PMU) for supplying electrical energy to a circuitry of a portable electronic device includes a power supply module, a power detection module connected to the power supply module, and a power control module connected to the power detection module and the circuitry. The power supply module includes a battery, a charge controller, and an adapter. The power detection includes a detection resistor connected to the battery, the charge controller, and the adapter. The battery or the adapter provides electrical energy to the circuitry. The adapter further charges the battery to charge the battery when it is used to provide electrical energy to the circuitry. The charge controller detects the current for charging the battery via the detection resistor, and regulates the current for charging the battery when the charging current exceeds a predetermined value.

Abstract: A system (1-2) for efficiently transferring harvested vibration energy to a battery (6) includes a piezo harvester (2) generating an AC output voltage (VP(t)) and current (IPZ(t)) and an active rectifier (3) to produce a harvested DC voltage (Vhrv) and current (Ihrv) which charge a capacitance (C0). An enable circuit (17) causes a DC-DC converter (4) to be enabled, thereby discharging the capacitance into the converter, when a comparator (A0,A1) of the rectifier which controls switches (S1-S4) thereof detects a direction reversal of the AC output current (IPZ(t)). Another comparator (13) causes the enable circuit (17) to disable the converter (4) when the DC voltage exceeds a threshold (VREF), thereby causing the capacitance be recharged.

Abstract: A system and method for battery protection. In some aspects, a battery pack includes a housing, a cell supported by the housing, a circuit supported by a flexible circuit board. The circuit is operable to control a function of the battery pack.

Abstract: A charging system includes a secondary battery which includes a heat-resistant member between a negative electrode and a positive electrode thereof, a charging-voltage supply section which conducts a constant-voltage charge of the secondary battery, a charge control section which controls the operation of the charging-voltage supply section, and a mode-setting acceptance section which chooses and accepts the setting of either of an ordinary charge mode and a high-voltage charge mode. When the ordinary charge mode is accepted, the charge control section conducts a constant-voltage charge of the secondary battery by supplying a voltage equal to, or below, the reference voltage, and when the high-voltage charge mode is accepted, the charge control section conducts a constant-voltage charge of the secondary battery by supplying a voltage above the reference voltage.

Abstract: To prevent a battery pack from being over-discharged even under a state that the battery pack (a secondary battery) is connected to a discharging device that is not connected to an ac input power source for a long time. A charging device has a pair of output lines and an anode terminal and a cathode terminal of a secondary battery electrically connected between the output lines to carry out a charging operation. In the charging device including a component circuit part electrically connected by traversing a part between the pair of output lines, a switching element is inserted between the component circuit part and one of the pair of output lines. When the charging device is not connected to an input power source, the switching element is allowed to be non-conductive to interrupt a discharging path so that the component circuit part does not form the discharging path.

Abstract: An apparatus comprises a first energy storage device configured to output a DC voltage, a first bi-directional voltage modification assembly coupled to the first energy storage device, and a charge bus coupled to the first energy storage device and to the first bi-directional voltage modification assembly. The apparatus also comprises high-impedance voltage source coupleable to the charge bus and a controller configured to monitor a transfer of charging energy supplied from the high-impedance voltage source to the first energy storage device. The controller is also configured to compare the monitored transfer of charging energy with a threshold value and, after the threshold value has been crossed, control the first bi-directional voltage modification assembly to modify one of a voltage and a current of the charging energy supplied to the first energy storage device.

Abstract: A monitoring circuit for accurately monitoring a voltage level from each of a plurality of battery cells of a battery pack includes an analog to digital converter (ADC) and a processor. The ADC is configured to accept an analog voltage signal from each of the plurality of battery cells and convert each analog voltage signal to a digital signal representative of an accurate voltage level of each battery cell. The processor receives such signals and provides a safety alert signal based on at least one of the signals. The ADC resolution may be adjustable. A balancing circuit provides a balancing signal if at least two of the digital signals indicate a voltage difference between two cells is greater than a battery cell balance threshold. An electronic device including such monitoring and balancing circuits is also provided. Various methods are also provided.

Abstract: A device controls charging a battery with power supplied from a power supply located outside of a vehicle through a charge cable. The device includes a first microcomputer and a second microcomputer. The first microcomputer is configured to turn on a charge mode signal upon detecting a change in a pilot signal output through the charge cable, and to turn off the charge mode signal when a charge completion signal output from the second microcomputer is turned off. The second microcomputer is configured to charge the battery through the charge cable when the charge mode signal is turned on, and to turn off the charge completion signal when the charging is complete. When the charge completion signal is turned on at the time of the first microcomputer turning off the charge mode signal due to sudden fluctuations, the charge mode signal is turned on again.

Abstract: A battery charging circuit for charging a rechargeable battery and improving operating stability includes a plurality of resistors for generating a first voltage; a first reference voltage source for providing a first reference voltage; an error amplifier for generating a second voltage according to the voltage difference between the first reference voltage and the first voltage; a second reference voltage source for providing a second reference voltage; a modulator for generating a control voltage according to the second reference voltage and the second voltage; a voltage-to-current control unit for generating a control current according to the control voltage; and a current mirror for generating an output current which is equal to a multiple of the control current, wherein the output current and its corresponding output voltage is applied to charge the rechargeable battery.

Abstract: An apparatus for automatically switching and charging a first battery and a second battery includes a charger unit; an output port configured for connecting to a load; a first control switch connected between the charger unit and the first battery; a second control switch connected between the charger unit and the second battery; a first output switch connected between the first battery and the output port; a second output switch connected between the second battery and the output port; a main control unit connected with the first and second batteries, the first and second control switches, and the first and second output switch modules; and a power source module configured for providing power to the main control unit and the charger unit.

Abstract: An aspect of the present invention provides a circuit for generating a voltage that can be used to recharge a battery. The circuit includes an inductive voltage generator operable to generate a magnetic field when the voltage generator is energized by power, and operable to generate a voltage from the magnetic field's collapse when the voltage generator is de-energized, and a switch operable to allow the voltage generator to receive power to energize the voltage generator, and operable to disconnect the power from the voltage generator to de-energize the generator. With this circuit, a power source that generates less voltage than the fully charged capacity of a rechargeable battery can be used to recharge the battery. Also, the circuit can convert power in different forms, such as constant direct current, varying direct current, or alternating current, into a second voltage for charging a battery.

Abstract: A power conversion controller includes: a correction-value calculating unit that calculates a correction value DE2 to correct a voltage value BEFC from a voltage signal BEFC that is obtained by converting the voltage value BEFC detected by a first voltage detector into a digital signal by an A/D converter and from a series-total voltage value EBAT detected by a second voltage detector; a corrected-voltage calculating unit that calculates a voltage signal BEFC1 as a corrected voltage value that is obtained by correcting the voltage value BEFC by the correction value DE2; and a gate controller that controls a power converting unit based on the voltage signal BEFC1

Abstract: A method and apparatus is disclosed to restore or recharge one or more cells of a battery. A switching module sources an element charging current from a first input voltage to the battery when a charging control signal is at a first logical level or sinks an element discharging current from the battery to a second input voltage when the charging control signal is at a second logical level. A controller module provides the charging control signal based upon a comparison of a reference voltage and a control voltage pulse, the control voltage pulse being generated by the controller module in response to a replica current, the replica current being proportional to the element charging current. A feedback module compares a voltage of the battery to a reference voltage to provide a charging error signal.

Abstract: For operating each smart battery included in a smart battery system, the smart battery is initialized prior to the smart battery being electrically coupled to the smart battery system. The smart battery system or an external power source is selected to provide power to an information handling system device. The smart battery includes an electronics device, a charge switch and a discharge switch. The electronics device operates the charge and discharge switches to jointly control an operating condition of the smart battery in response to receiving a control input from a controller of the device. The charge and discharge switches are closed in response to the electronics device and the controller being in agreement to charge the first smart battery. The charge or the discharge switch is opened in response to either the electronics device or the controller directing either of the switches to be opened.

Abstract: A battery pack which includes a battery pack electronic control circuit adapted to control an attached power tool and/or an attached charger. The battery pack includes additional protection circuits, methodologies and devices to protect against fault conditions within the pack, as the pack is operatively attached to and providing power to the power tool, and/or as the pack is operatively attached to and being charged by the charger.

Abstract: A system includes a sensing module and a switching module. The sensing module is configured to sense output voltages of first and second cells connected in series in a rechargeable battery stack. The switching module is configured to alternately connect a capacitance across the first cell and the second cell at a switching frequency when a difference in the output voltages is greater than or equal to a first threshold. The switching module is further configured to stop alternately connecting the capacitance when the difference is less than or equal to a second threshold, wherein the first threshold is greater than the second threshold.

Abstract: A battery management system for charging a battery by a charger includes a transistor and either a charge pump or a push-pull output driver. The transistor increases and decreases an electrical connection between the battery and a voltage from the charger and transmits a charge current from the charger to the battery by turning on and off in response to a pulse width modulated drive signal generated by the charge pump or the push-pull output driver. The charge pump or the push-pull output driver increases the drive signal when the voltage from the charger is above a pre-charge threshold voltage and decreases the drive signal when the voltage from the charger is below the pre-charge threshold voltage.

Abstract: A battery charging circuit comprising: a semiconductor switch having an output connected to a rechargeable battery; a battery charge controller for receiving power from an external source, and supplying output power to a portable device and the input of the semiconductor switch, the current output of the battery charge controller being controllable; and a voltage sensing circuit for: measuring the voltage drop across the battery charge controller; and responding to the voltage drop across the battery charge controller by modulating the semiconductor switch to reduce the quantity of current supplied to the rechargeable battery when the voltage drop is too great; whereby the total power dissipated by the battery charge controller is controlled, the portable device receiving the power it needs to operate and the rechargeable battery receiving any additional available power.

Abstract: There is provided a power supply capable of reducing switching elements. In a power supply, an AC/DC adapter 121 supplies electric power to a load 125 and a battery charger 122. The battery charger comprises a high side FET 102 and a low side FET 103 which operate according to a synchronous rectification method, and charges batteries 108 and 109. When a commercial power supply fails, a power outage detection circuit provided in the battery charger detects the power outage, and outputs a power outage signal. The battery charger which has received the power outage signal sets the high side FET to be ON KEEP. A discharge current from the battery flows via a discharge path 119. This enables a reduction in the number of FETs in comparison with other power supplies.

Abstract: A charging circuit integrated into a chip, comprising a charging unit, a switch unit, a biasing unit, a voltage-dividing unit, and a comparing unit. The charging unit is connected between a power supply input and a load for outputting a constant current based on a constant bias voltage supplied by the power supply input in order to charge the load. The switch unit is connected between the charging unit and the power supply input for turning on or cutting off the charging unit. The voltage-dividing unit generates a first signal to the comparing unit according to a voltage of the load. The biasing unit outputs a second signal having a constant voltage to the comparing unit. The comparing unit compares the first signal with the second signal for cutting off or turning on the switch unit, bringing the charging unit to charge or stop charging the load, respectively.

Abstract: A method for charging a battery of an electronic device using a connected a/c power adapter comprising the steps of determining a state of a transistor connecting a regulated voltage to the battery and switching a charging current applied to the battery between a quick charge level and a trickle charge level responsive to the state of the transistor.

Abstract: An uninterruptible power supply (UPS) having an adjustable battery charger that generates a charger current, and a controller, coupled to the adjustable battery charger, that receives a signal representative of a system constraint and provides a reference, based on the signal, to the adjustable battery charger to control an amplitude of the charger current supplied by the adjustable battery charger based on the system constraint. The system constraint may include, for example, a maximum input current to the UPS, maximum charging current of the battery cell, and maximum and/or minimum charger current values.

Abstract: A power tool 1 is connected to a battery pack 5 including an overcurrent detector 533 which detects overcurrent of a battery module 51 and outputs a detection signal, and an overdischarge detector 532 which detects overdischarge of the battery module 51 and outputs a detection signal. The power tool 1 includes a motor 2 which is driven by electric power supplied from the battery pack 5, a trigger switch 31 for setting the power supply from the battery pack 5 to the motor 2 in ON/OFF state, and an FET 410 which sets the power supply to the motor 2 in ON/OFF state on the basis of the detection signal from the overcurrent detector 533 or the overdischarge detector 532.

Abstract: A power tool 1 is connected to a battery pack 5 including an overcurrent detector 533 which detects overcurrent of a battery module 51 and outputs a detection signal, and an overdischarge detector 532 which detects overdischarge of the battery module 51 and outputs a detection signal. The power tool 1 includes a motor 2 which is driven by electric power supplied from the battery pack 5, a trigger switch 31 for setting the power supply from the battery pack 5 to the motor 2 in ON/OFF state, and an FET 410 which sets the power supply to the motor 2 in ON/OFF state on the basis of the detection signal from the overcurrent detector 533 or the overdischarge detector 532.

Abstract: For a circuit for preventing overcharging of a battery cell, the overcharging protecting circuit having a voltage detector for monitoring the voltage across the battery cell, a polarity protection circuit for protecting the voltage detector from a reverse polarity connection of the battery cell to the voltage detector is disclosed. The polarity protection circuit comprises a semiconductor device coupled across voltage detection inputs of the voltage detector. The semiconductor device is adapted to shunt current across the voltage detection inputs of the voltage detector when the battery cell is connected in reverse polarity to the voltage detector.

Abstract: Provided are a battery state monitoring circuit with a small number of terminals and a battery device including the battery state monitoring circuit. An output of an overcharge detection circuit (12) is an open-drain output to a charge control terminal (18), and an input terminal of a voltage detection circuit (11) is connected to the charge control terminal (18), to thereby share a charger detection terminal and a charge control terminal.

Abstract: A pair of measuring switches S21, S22 is interposed between both terminals of a capacitor C, and inputs T1, T2 of A/D converters 11c, 11d via resistors R1, R2. A pair of measuring switches S23, S24 is interposed between both inputs T1, T2 and a ground. The CPU 12a controls the measuring switches S21 to S24 so that when a terminal “a” of the capacitor C is positive charged, while the other terminal “b” of the capacitor C is grounded, both terminals “a” and “b” are respectively connected to the inputs T1 and T2. The CPU 12a controls the measuring switches S21 to S24 so that when the terminal “b” of the capacitor C is positive charged, while the terminal “a” of the capacitor C is grounded, both terminals “a” and “b” are respectively connected to the inputs T1 and T2.

Abstract: The object is to provide a safe non-contact electric power transmission apparatus reducing unnecessarily consumed electric power, while intermittently-operated or otherwise restrained electric power transmission is not performed, and heat is not generated when a metal such as a foreign object is placed.

Abstract: A bicycle power supply module is for supplying power to electrical devices on a bicycle. The bicycle power supply module includes a bicycle hub dynamo mounted on a hub of the bicycle for generating an AC power, an AC to DC converting module coupled to the bicycle hub dynamo for converting the AC power generated by the bicycle hub dynamo into a DC power, an energy storage module for storing electrical energy, and a charger coupled to the AC to DC converting module and the energy storage module for receiving the DC power converted by the AC to DC converting module and for charging the energy storage module with the DC power.

Abstract: A universal serial bus battery includes a universal serial bus interface, a battery, a charger, a comparator, a first switch, and a second switch. The comparator is configured for comparing the voltage at the universal serial bus interface and the voltage of the battery, and to produce an ON signal when the voltage at the serial bus interface exceeds the voltage of the battery, or to produce an OFF signal otherwise. The first switch is configured for establishing an electrical connection between the USB interface and the charger upon receiving the ON signal or cutting off the connection upon receiving the OFF signal. The second switch is configured for establishing a connection between the universal serial bus interface and the battery when the connection between the USB interface and the charger is terminated by the first switch.

Abstract: A battery takes in a charge current value or a discharge current value from a current detection device at predetermined sampling intervals. Then, based upon the current value, a power consumption quantity representing the extent to which power has been consumed during a sampling interval is calculated and a total power consumption quantity is determined by sequentially adding the power consumption quantity corresponding to each sampling interval. Based upon the total power consumption quantity calculated at each sampling interval, a determination device determines as to whether or not the battery needs to be refreshed, and the determination results are transmitted to the camera. The camera informs the user that the battery needs to be refreshed if the determination device judges that a refresh operation is necessary. The sampling interval may be set longer when the power to the camera is in an OFF state compared to when the power to the camera is in an ON state.

Abstract: A battery charging circuit includes a power input unit for supplying power to charging units and a control module. Each charging unit includes a connecting port for connecting one battery, an electromagnetic coil and a switch module connected between the connecting port and the electromagnetic coil. The connecting ports are series-connected with one another. The control module is used for monitoring the voltage of the batteries and then controlling a work state of the switch modules by means of comparing a voltage variance between any two of the batteries with a specific data set in the control module so as to make the battery with a greatest voltage discharged to produce a discharge current for secondarily charging the other batteries by means of the electromagnetic coils when the voltage variance is greater than the specific data.

Abstract: Charging and discharging lines for a rechargeable battery are arranged independently from each other, and as a protection circuit for the rechargeable battery, there are provided a nonreturn-type switch (for example, thermo-fuse with an internal heater) that is interposed in the charging line in series and interrupts the charging line by blowout and a semiconductor switch (for example, MOS-FET) that is interposed in the discharging line in series and electrically continues or interrupts the discharging line. The switch control circuit turns off the semiconductor switch element when detecting overdischarge of the rechargeable battery, and blows out the nonreturn-type switch when detecting overcharge of the rechargeable battery or a malfunction of the semiconductor switch element.

Abstract: In a charge control circuit that adjusts a charging current flowing through a battery to be charged from a power supply, a sense resistor is provided on a charging path to the battery from an external power supply. A charging current adjustment circuit adjusts the charging current based on an error voltage between a voltage drop across the sense resistor and a predetermined reference voltage. The charging control circuit is integrated in a package. The charging current is inputted to a current input terminal. A battery terminal outputs the charging current to the battery. The current input terminal and the battery terminal also function as terminals used to measure a resistance value of the sense resistor. A voltage monitoring terminal is provided to measure the reference voltage in an inspection process.

Abstract: Embodiments of the present invention include techniques for charging a battery using a switching regulator. Some embodiments include programmable switching battery chargers that can be configured using digital techniques. Other embodiments include switching battery chargers that modify the battery current based on sensed circuit conditions such as battery voltage or input current to the switching regulator. In one embodiment, the present invention includes a USB battery charger.

Abstract: A battery charger includes an accommodating part for accommodating a group of cells and a plurality of cell assemblies respectively having charging terminals for charging the group of cells; a first terminal plate formed in the surface of the accommodating part to come into contact with the charging terminal of the first cell assembly and a second terminal plate coming into contact with the second cell assembly; a switching element for interrupting voltage from an ac power source; a unit for rectifying and smoothing the voltage interrupted by the switching element; and a unit for applying the smoothed dc voltage respectively to the first and second terminal plates.

Abstract: A charge control circuit used to control a battery to charge includes a power management unit, a voltage converting unit, a voltage comparison unit, and a switch control unit. The power management unit supplies a voltage to the battery. The voltage converting unit provides a reference voltage to the voltage comparison unit. The voltage comparison unit compares a battery voltage obtained from the battery with the reference voltage, and sends a comparison to the switch control unit. The switch control unit controls the power management unit to charge or stop charging the battery according to the comparison.

Abstract: The charging circuit for charging a battery of an electronic device using a connected AC power adaptor includes circuitry responsive to an applied regulated voltage for charging the battery connected to the charging circuitry. The circuitry prevents the regulated voltage applied to the circuitry from falling below a settable voltage level. Additionally, the circuitry switches a charging current between a quick charge level and a trickle charge level responsive to a state of a transistor.

Abstract: A charging circuit with an application system thereof provides an error amplifier to control a transistor switch for controlling the charging power source to charges the battery. When the voltage difference between the power source and load terminals of the transistor switch drops along with the transistor switch being turned on, the output voltage of the error amplifier changes as well to increase the turning-on resistance of the transistor switch such that the voltage difference between the power source and load terminals is capable of maintaining at a value above a certain reference level for avoiding the unstable state resulting from the charging circuit being turned on and off frequently.

Abstract: A system includes an input configured to connect to a power source providing an input voltage, an output configured to connect to a load and to transfer power from the power source to the load, a battery selectively coupled to the input to receive current from the power source, a detector configured to indicate whether the input voltage drops more than a threshold amount, and a processor configured to regulate the selective coupling of the battery to the input to regulate a charging current supplied to the battery, the processor configured to regulate the selective coupling such that if a first charge current induces a drop in the input voltage beyond the threshold amount, then the processor will change the charging current to a second charge current that is lower than the first charge current.

Abstract: A system and method for battery protection. In some aspects, a battery pack includes a housing, a cell supported by the housing, a circuit supported by a flexible circuit board. The circuit is operable to control a function of the battery pack.