Abstract: A method for charging portable electronic device is disclosed. When the portable electronic device is connected to a power source, the method selects a protecting mode or a fast charging mode to charge the battery according to the current operating status of the portable electronic device. Simultaneously, the battery power is also controlled within a safety range. Therefore, the invention can charge the battery of the portable electronic device at a high speed without affecting the efficiency of the device. Moreover, the battery is also protected from being overcharged to extend the life of the battery.

Abstract: Techniques are disclosed to control output power from a switching power supply. For example, a switching regulator according to aspects of the present invention includes a switch to be coupled to an energy transfer element of a power supply. A controller is coupled to the switch to control a switching of the switch to regulate an output voltage and an output current at an output of power supply output. A feedback circuit is coupled to the controller. The feedback circuit is coupled to receive a feedback signal from the output of the power supply. Combinations of the output voltage and the output current correspond to output regions. There is at least one regulated output region and one unregulated output region. At least one unregulated output region is a self protection auto-restart region. Within at least one unregulated output region, the switching regulator provides continuous output power at substantially the maximum output power of the switching regulator.

Abstract: A serial charger with the function of automatic change of charging speed for NiCd/NiH batteries is provided where the different charging modes for multi-speed (four speed) charging process, two speed charging process or two speed charging process in two charging phases can be achieved by use of the speed-changing principle with a low power consumption of an exchange power unit. The finished charging time of each battery varies inversely as the number of the detected batteries to be charged. No matter whether the charging voltage is variable or constant, the charging current varies automatically to achieve the speedy charging process or the normal charging process even under low power consumption. Accordingly, an exchange power unit can be reduced in size and built in the charger so that the charger is convenient to carry and the finished charging time can be adjusted automatically according to the demand of battery consumption of customers.

Abstract: The invention concerns a method (200) and a system (100) for charging a battery (112). The method includes the steps of determining (214) a charge termination point for the battery, in which the charge termination point produces a charge on the battery that is less than an initial maximum charging capacity of the battery, and charging (224) the battery using the charge termination point for at least a portion of the charge cycles of the battery. The method reduces at least in part the variation of battery capacity over the cycle life of the battery.

Abstract: A multi-battery automatic charging circuit with individual regulator is further provided with one secondary or more than one output interface to convert an AC source via a rectifier into a DC charging source, thus to supply power to an external rechargeable device or a DC load of different voltage through a tap of the circuit specific voltage; or alternatively, a primary battery, or a rechargeable battery provided with storage capacity, or any other rechargeable device generally available in the market is placed in the battery holder provided otherwise for the placement of rechargeable batteries to charge the external rechargeable device or to supply power to a DC load.

Abstract: Disposed in a secondary side circuit of an AC adapter (10A), a??I detection circuit (45) detects that a charging current (Ic) lowers less than a set current value to produce a detected signal. A voltage control circuit (42A) operates so as to repeat the steps of gradually lowering an adapter voltage (VADP) and of heightening the adapter voltage in response to the detected signal.

Abstract: A current trip point detection circuit includes a transistor, a series of resistors, an amplifier, a comparator, and a series of switching circuits. The first transistor and the resistors are configured as an inverting gain stage. The amplifier cooperates with the first transistor to operate in a negative feedback arrangement. The gain in the feedback loop is adjusted by selective activation of additional transistors, where each additional transistor lowers the overall loop gain. The comparator is selectively coupled to a tap point in a voltage divider that is formed by resistors. The voltage divider tap point is selected to set a threshold for detection. The trip point is detected by the comparator, and may be adjusted between high and low trip points through the various configurations of the gain and voltage divider tap points via the switching circuits.

Abstract: A battery charging circuit having two levels of safety protection is provided. The circuit is said to have “two levels” of safety because if any one component fails (either as a short circuit or as an open circuit) the remainder of the charging circuit ensures that a rechargeable battery coupled to the circuit will not be overcharged. The circuit includes both hardware and firmware protection components, with a microprocessor providing the firmware protection. Overvoltage protection, voltage regulation and current regulation are provided, along with a microprocessor capable of sensing a plurality of voltages across the circuit. The overvoltage protection, voltage regulator and current regulator each include safety actuation points. In parallel, the microprocessor may isolate a rechargeable battery from the cell if voltage and current minimums and maximums are exceeded.

Abstract: A battery charger includes a supply voltage unit supplying a power supply voltage, a constant current generator receiving the power supply voltage and outputting a substantially constant current, and a timer whose output is coupled to the constant current generator. The timer outputs the timer output in response to a transition in the power supply voltage. The supply voltage unit changes a magnitude of the power supply voltage in response to the timer output so that the substantially constant current is changed from a first current level to a second current level.

Abstract: A method for determining time to completion is provided for a battery charging system. The system preferably includes a charger having a microprocessor and a battery with a memory. The memory includes information about the battery, including battery identifiers, charging states, charging procedures and charging termination information. The charger reads this battery and then determines the charging states associated with the battery. The charger then determines the present state of charge, and calculates a time to completion for that state. The charger then determines times to completion for the remaining charge states, optionally compensating for self discharge within the battery. A total time to completion is determined by summing the times to completion for the respective charging states.

Abstract: A lithium-ion cell includes a carbonaceous anode and a lithiated metal oxide cathode, with a plastic spacer therebetween and liquid electrolyte containing lithium salts. The cell stands for a period of time aller electrolyte is added. The cell is then charged at a first current density of about ¼ mA/cm2 for at least an hour. Following the first charge, the cell stands open-circuited for at least an hour. The cell is again charged, at a current density significantly greater than the first current density, until the cell reaches a particular voltage which corresponds with the desired cell capacity, and gases are vented. After the second charge, the cell is discharged at a relatively high current density toward a particular voltage, so as to leave less active lithium ions in the anode structure. After discharge, the lithium ion cell is sealed and ready for charging by a user.

Abstract: A multi-battery automatic charging circuit with individual regulator is further provided with one secondary or more than one output interface to convert an AC source via a rectifier into a DC charging source, thus to supply power to an external rechargeable device or a DC load of different voltage through a tap of the circuit specific voltage; or alternatively, a primary battery, or a rechargeable battery provided with storage capacity, or any other rechargeable device generally available in the market is placed in the battery holder provided otherwise for the placement of rechargeable batteries to charge the external rechargeable device or to supply power to a DC load.

Abstract: A method of controlling the charging of a secondary battery (battery) without deterioration of a charging/discharging characteristic of the battery. An ordinary charging portion performs a first charging control specified to stop the charging at a charge level less than a full-charge level is used in combination with a refresh charging portion for performing a second charging control specified to stop the charging at a charge level more than the full-charge level. When the charging by the ordinary charging portion is continuously repeated by, for example, 10 times, a switching portion is switched such that the next charging is performed by the refresh charging portion. A counter, which is reset when the charging by the refresh charging portion is terminated, is provided for deciding whether or not the number of times of the repeated charging reaches 10.

Abstract: A four-stage charging technique for nickel-zinc cells and batteries, is provided, whereby a high cycle life is assured, without dendrite formation or harmful overcharge, with minimal shape change of the zinc electrode, and with minimal oxygen recombination. In the first stage, the nickel-zinc cell or battery is charged with an average current less than C/5 for a period of less than five minutes, or until the terminal voltage of a cell reaches 1.75 volts to 1.79 volts. In the second stage, a fast charge is imposed, until the terminal voltage of a cell reaches between 1.88 volts and 1.92 volts. In the third stage, a moderate charge is imposed, until the terminal voltage of a cell reaches 1.90 volts to 1.94 volts. The fourth stage gives a trickle charge when the terminal voltage is greater than 1.94 volts.

Abstract: A temperature sensing device for use in a secondary battery pack includes an NTC element and a current limiter element. The NTC element is disposed at a predetermined position to sense the temperature of a secondary battery incorporated in the secondary battery pack, and one end thereof is electrically connected to a temperature sensing terminal. The current limiter element is connected between the other end of the NTC element and a reference potential terminal.

Abstract: Polarized electric charge storage devices economically provide high available capacitance. The present invention directly employs polarized electrical charge storage (PECS) devices such as polarized capacitors or electrochemical batteries in general AC applications with a novel circuit topology. In one embodiment, an anti-series configuration of first and second PECS devices are used within an AC network for enhancing operation of the AC network. At least one DC source is provided for maintaining the PECS devices forwardly biased while they are subjected to an AC signal. The AC signal, which drives an AC load, is applied to the anti-series devices. The devices are sufficiently biased by the at least one DC voltage source so that they remain forwardly biased while coupling the AC signal.

Abstract: A power source circuit is provided which is capable of improving an efficiency of using energy of a chemical battery cell and of responding suitably to an intermittent change in a load current. Since, during a load burst period in an odd-numbered order, a load is driven by power accumulated in a first power storing section and, during a load burst period in an even-numbered order, a load is driven by power accumulated in a second power storing section, even if a duty ratio of the load burst period in one period during which the load burst period occurs intermittently exceeds fifty percent, energy required during the load burst period is fed from the first or the second power storing section and the chemical battery cell does not discharge during the load burst period.

Abstract: An initial charging operation is carried out by a charging step composed of two-stages or more to improve an initial charging and discharging efficiency, reduce the charge of wasteful materials and improve a high capacity and a high cyclic characteristic without deteriorating various kinds of battery properties. In order to realize the improvements, a nonaqueous solvent which is decomposed under a potential higher than the reduction and decomposition potential of a main solvent is included in electrolyte. This charging method is a method for achieving the addition effect of such a nonaqueous solvent as much as possible. As a specific means, the electrolyte to which vinylene carbonate is added is employed and a constant-current and constant-voltage charge under about 3.2 V is carried out for 1 to 2 hours before a battery is completely charged. Thus, a good coat can be formed on the surface of an anode while suppressing the quantity of electricity required for forming the coat.

Abstract: A battery charging method and system, the battery charging method comprising: charging at least one battery at a first voltage for a first time duration; charging the batteries at a second voltage for a second time duration; determining state of charge of the batteries at the end of the second time duration; if the batteries are not substantially fully charged at the end of the second time duration, the total charging time is evaluated to determine if the batteries have been charged for a time duration greater than or equal to a third time duration, and if the total charging time has not exceeded or is not equal to the third time duration, charging the batteries at the first voltage for the first time duration and charging the batteries at the second voltage for the second time duration is repeated; if the batteries are substantially fully charged at the end of the second time duration, battery charging is ceased; or if the total charging time has exceeded or is equal to the third time duration at the end of

Abstract: A circuit for reducing leakage current through one or more output transistors (312) includes a capacitor circuit (302) and additional circuitry. The capacitor circuit (302) stores and discharges a charge, thus providing a current having a limited duration, which is related to a discharge time of the capacitor circuit. In one embodiment, the additional circuitry includes a current source circuit (304), an amplifier circuit (307), and one or more transistors (308, 310). The current source circuit is temporarily activated by the current from the capacitor circuit, and provides a second current to the amplifier circuit. The amplifier circuit amplifies the second current, and the amplifier current is used to activate the transistors (308, 310). When activated, the transistors draw current from the control terminals (e.g., the bases) of the output transistors (312) after the output transistors have been switched off, thus reducing leakage currents through the output transistors.

Abstract: A system for actively controlling the charging profile of a battery uses a software-based alternator control unit to control the charging voltage. The system optimizes battery and alternator life. The system, on a dynamic basis, uses battery open-circuit voltage (OCV) to estimate battery state-of-charge (SOC). Also, the charging current of the battery is periodically estimated; this, after processing, provides an estimated SOC of the battery.

Abstract: A lithium-ion cell includes a carbonaceous anode and a lithiated metal oxide cathode, with a plastic spacer therebetween and a liquid electrolyte containing lithium salts. The cell is allowed to stand for a period of time after the electrolyte is added. The cell is then charged at a first current density of about ¼ mA/cm2 for at least an hour, and preferably for six hours. Following the first charge, the cell is allowed to stand open-circuited for at least an hour, and preferably for eight hours. After the open-circuit interval, the cell is again charged, this time at a current density significantly greater than the first current density, until the cell reaches a particular voltage, which in one case is 4.1 volts, which corresponds with the desired cell capacity, and gases are vented. In one version, the second charge density is ½ mA/cm2. After the second charge, the cell is discharged at a relatively high current density toward particular voltage, which in one mode of the method is 2.

Abstract: A method for charging a rechargeable battery pack includes providing a charger having first and second charging processes, and manually selecting one of the first and second charging processes. The charging method may include a step for indicating status or end of the selected one charging process. The first charging process may include the steps of providing a fast charging current, indicating end of the fast charging current and providing an equalization current. The second charging process may include the steps of providing a fast charging current, subsequently providing an equalization current and indicating end of equalization current. The second charging process may also include a temperature checking step. Further disclosed is a battery charging apparatus including a charger for charging a battery and having first and second charging processes, and a switch connected to the charger for manually selecting one of the first and second charging processes. The charger may include a microprocessor.

Abstract: A battery charging method and system, the battery charging method comprising: charging at least one battery at a first voltage for a first time duration; determining state of charge of the batteries at the end of the first time duration; if the batteries are substantially fully charged at the end of the first time duration, charging the batteries at the first voltage for a second time duration, and charging the batteries at a second voltage for a third duration of time; if the batteries are substantially fully depleted at the end of the first time duration, charging the batteries at the first voltage for an alternate second time duration, and charging the batteries at the second voltage for an alternate third duration of time.

Abstract: A method for charging a battery pack including a plurality of battery units includes: a first step of charging the battery units with a first electric current at a first rate until an internal pressure of at least one of the plurality of battery units begins to increase; and a second step of charging/discharging the battery units with a second electric current which is lower than the first electric current at a second rate which is lower than the first rate after the internal pressure of the at least one of the plurality of battery units has begun to increase.

Abstract: A charge termination circuit which may be disposed within the battery cell pack and used in conjunction with known battery safety circuits to protect against charging conditions which reduce the life of a battery cell. In particular, the charge termination circuit is adapted to be used in conjunction with an off the shelf battery safety circuit and one or more power FETs coupled between the battery cell and the battery charger terminals on the battery cell package. The charge termination circuit includes a microcontroller and monitors the battery cell voltage by way of an I/O part and activates a first timer anytime the charging current to the battery is below a predefine threshold, for example, indicative of a maintenance or trickle charge. When the first timer times out after a predetermined time period, for example, two hours, the charge termination current forces the one or more of the serially coupled FETs switches to interrupt battery charging of the battery cells.

Abstract: An improved asymmetrical charger for charging a plurality of batteries of different capacity and voltage values, and automatically judging the residual power capacity and charge saturation level of every battery mainly includes a control unit, a voltage detection unit, a battery dock, an alternate power supply circuit, a current detection and rapid/slow charging switch unit, a battery detection unit, and a human machine interface. The battery dock is connected to a main circuit of the alternate power supply circuit, and connects in series at least one battery chamber which has two parallel circuits; one of the parallel circuits has a short circuit switch driven by the current detection and rapid/slow charging switch unit and another one of the parallel circuits has a positive conductor and a negative conductor to connect a battery thereby to provide a safe charger for charging batteries of different capacities without risking overcharge or undercharge of the batteries.

Abstract: In a charging system used in a computer system employing a rechargeable battery, the number of charging/discharging cycles of the battery is detected based on a charging amount of the battery by a charger. A charging condition for the charger is set to increase the capacity of the battery until the number of charging/discharging cycles reaches a predetermined value, and the charging condition for the charger is set to increase the life of the battery after the number of charging/discharging cycles has reached the predetermined value.

Abstract: A battery charger for a lead acid battery having a power supply with an input connected to an AC signal and an output connected to the battery. The power supply provides a charge current to the battery. A clock connected to the AC signal provides clock pulses having transitions synchronized with zero crossings of the AC signal. A voltage monitor connected to the battery detects a battery voltage substantially simultaneously with a zero value of the charge current. A charge mode control is connected to the clock and the voltage monitor for commanding different battery charge currents. The voltage monitor includes a temperature compensation circuit. The battery charger includes a display module that can be placed at a location remote from the battery charger and convenient to the user.

Abstract: A battery charger for charging at least two storage batteries, comprises: a first charging pocket for receiving a first storage battery; a second charging pocket for receiving a second storage battery; a main controller for generating a power supply control signal, charging voltage setting control signal according to the voltage types of the batteries inserted in the first and second charging pockets, and charging current setting control signal according to the current capacities of the batteries; a voltage adjustment circuit for adjusting the charging voltage to the levels respectively fit for the voltage types of the batteries according to the charging voltage setting control signal; a current adjustment circuit for adjusting the charging current to the levels respectively fit for the current capacities of the batteries according to the charging current setting control signal; and a power supply control circuit for supplying or blocking the charging voltages to the batteries according to the power supply co

Abstract: In a battery accumulating apparatus, a charge current I1 from the charging solar battery 9 is supplied to the storage battery 5 through the switch 10, and charges the storage battery 5. The charge controller 4b detects each cell voltage of the storage battery 5, and when any cell voltage reaches a prescribed value, the charge controller 4b turns the switch 10 which is in the ON status to the OFF status. The charge controller 4b has a function which generates the charge currents I2 and I3 (I2>I3) whose levels are lower than the charge current I1, according to the output from the charging solar battery 9, and which supplies the charge current I2 to the storage battery 5 to charge the battery at the same time as the turning OFF of the switch 10. The storage battery 5 is charged by the charge current I2, and when any cell voltage reaches a prescribed value, the charge controller 4b switches the charge current I2 to the charge current I3, and supplies the charge current I3 to the storage battery 5.

Abstract: The present invention is to provide an improved strategy for actively controlling battery state of charge (SOC) as a function of the vehicle's kinetic energy. A vehicle system controller (VSC) can vary a target battery SOC as a function of vehicle speed based on either vehicle kinetic energy or the square of vehicle speed. The VSC can set a maximum battery SOC limit using vehicle velocity and actively control a rate of charging the battery and determine a target battery SOC as a balance between the charge time and the charge current. The VSC can determine a target battery SOC based on a predetermined constant and a predetermined offset value. Target battery SOC is increased as vehicle speed increases until the maximum battery SOC limit is reached.

Abstract: A system for actively controlling the charging profile of a battery uses a software-based alternator control unit to control the charging voltage. The voltage applied to the battery is initially increased over normal values following battery discharge, to charge the battery back as fast as possible without damaging the battery or alternator. The voltage is then reduced to a normal charging level, and subsequently further reduced to a float level.

Abstract: In a power supply of a patient care system, a power management system monitors the temperature of an off-line switcher and adjusts the amount of current supplied by the off-line switcher to operate the off-line switcher within a range of temperature and power limits.

Abstract: A method and apparatus for extending the cycle life of a battery by using different charge voltages or different current cut-offs to recharge the battery during the course of the battery's life. The capacity of a battery is gradually depleted as the battery is repeatedly charged and discharged. The rate at which the battery capacity is depleted varies in accordance to the charge voltage, or the current cut-off, used to recharge the battery. For example, higher charge voltages cause the capacity to be more rapidly depleted than lower charge voltages. A battery may be charged using a high charge voltage, e.g., its rated charge voltage, during periods of expected high usage. To extend the battery's cycle life, the battery may be charged using a low charge voltage during periods of expected low usage.

Abstract: In the method of fast-charging of a rechargeable battery, full-charge state is determined on the basis of a peak battery voltage or a decrease &Dgr;V in the battery voltage after the peak voltage. At the beginning of the fast-charge process, an initial battery voltage is measured. In case where the initial voltage is higher than a preselected voltage, the battery is fast-charged with a normal fast-charge current. In case where the initial voltage is lower than the preselected voltage, the battery is fast-charged with a restricted fast-charge current that is weaker than the fast-charge current.

Abstract: A battery charger, a method of charging a battery and a battery plant incorporating the battery charger or the method. In one embodiment, the battery charger includes: (1) a battery voltage monitor that measures a voltage of a battery and (2) a charge current generator, coupled to the battery voltage monitor, that provides an incrementally adjustable charge current to the battery based on the voltage.

Abstract: Provided is a method for increasing the cycle life of discharged lithium electrochemical cells, wherein the cell comprises (i) an anode comprising lithium; (ii) a cathode comprising an electroactive sulfur-containing material; and (iii) a liquid electrolyte interposed between the anode and cathode; wherein the method comprises the steps of: (a) charging the cell at an initial low rate of less than 0.2 mA/cm2 to a cell voltage in the range of 2.1 to 2.3 V followed by (b) a subsequent high rate of greater than 0.2 mA/cm2 to a cell voltage of at least 2.4 V.

Abstract: A method and apparatus for charging a rechargeable battery in which a constant current is first applied until the rated voltage of the battery is reached, followed by a period during which a reduced current is applied to the battery. The reduced current results in lowering the amount of unwanted heat being dissipated in the charge-current transistor connected to the battery. Finally, a constant voltage is applied to the battery to finish the charging cycle. Reducing the heat dissipation enables the use of smaller less expensive charge-current switch transistors, which for example, are advantageous in applications such as mobile communication devices or other portable electronics assemblies.

Abstract: The method and system for managing power supplied from a charging circuit to a power source in an implantable medical device comprises the steps of and circuitry for: measuring the current drain of the medical device; measuring the elapsed time since the last full charge of a power source of the device; calculating the actual capacity of the power source (corrected for fade) based on the variable of current drain and the variable of elapsed time; calculating the operating time based on the variable of current drain and the variable of the actual capacity of the power source; measuring the voltage of the power source; signaling the medical device when the power source voltage has reached a certain low value which requires disconnection from the power source; disconnecting, during discharging, the power source from the medical device upon the power source reaching a certain low voltage in order to prevent deep discharging of the power source and subsequent damage; precisely limiting the charging voltage to the

Abstract: In the method of fast-charging of a rechargeable battery, full-charge state is determined on the basis of a peak battery voltage or a decrease &Dgr;V in the battery voltage after the peak voltage. At the beginning of the fast-charge process, an initial battery voltage is measured. In case where the initial voltage is higher than a preselected voltage, the battery is fast-charged with a normal fast-charge current. In case where the initial voltage is lower than the preselected voltage, the battery is fast-charged with a restricted fast-charge current that is weaker than the fast-charge current.

Abstract: Apparatus for rapidly charging a battery including an output adapted to be electrically connected to a battery and a control device electrically connected to the output. The control device includes a power supply and a microcontroller. The microcontroller includes PWM firmware using software interleaving for controlling the power supply and a plurality of battery charging stages.

Abstract: A charging controller for charging a secondary battery by a dc source has a consumption current detector for detecting a consumption current flowing in a load, a charging control circuit controlling charging of the secondary battery; a charging circuit input current detector detecting a current to be input to the charging controller; and an operation processor to which detection outputs from the consumption current detector and the charging circuit input current detector are provided, respectively, the charging control circuit controlling the charging output to the secondary battery, based on calculation results obtained by the operation processor such that driving the load and charging are simultaneously executed within the ratings of the dc source.

Abstract: A charging controller for charging a secondary battery by a dc source has a consumption current detector detecting a consumption current of a load; a charging current detector detecting a charging current to the secondary battery; a charging voltage detector detecting a charging voltage to the secondary battery, a function-processor to which detection outputs from the consumption current detector, the charging current detector, and the charging voltage detector are provided, respectively, and a charging control circuit controlling a charging output to the secondary battery, based on calculation results by the function-processor such that driving the load and charging are simultaneously executed within the ratings of the dc source.

Abstract: An engine stopping/starting control unit having improved accelerating performance. A charging limiting device is provided which limits the charge provided to a generator when the vehicle is stopped. The decreased charging allows for better performance when the vehicle accelerates from a stopped states. Also, the vehicle headlight can be dimmed while the vehicle is stopped, which reduces the load on the generator. An acceleration detector detects when the vehicle accelerates during running, and can decrease the generator load in response to the acceleration.

Abstract: An especially low power, fast completion battery charge process varies the voltage, current, and time of charging a battery according to the battery's state of charge. Initially, a battery charger apparatus applies a fast charge current to the battery. When the battery voltage increases to a target voltage, the battery charger applies a fast charge voltage to the battery. This continues until the current flowing through the battery decreases to a prescribed minimum current. The battery charger then calculates the elapsed time between the battery's initially receiving the fast charge current and later achieving the minimum current. Using the elapsed time, the charger computes a proposed overcharge time comprising a multiplicative product of the elapsed time and a temperature-dependent adjustment factor. Next, the battery charger applies an overcharge voltage to the battery for the proposed overcharge time, unless the proposed overcharge time exceeds a prescribed maximum time.

Abstract: A capacitor can be charged at a high speed by applying a direct current voltage intermittently to the capacitor. The direct current voltage is intermittently applied to the capacitor such that a preceding applied voltage E1 is larger than a succeeding applied voltage E2. Thus, the charging is swiftly progresses and the capacitor can be charged at a higher speed than when the voltage is applied continuously.

Abstract: A method and apparatus for maintenance charging a battery is disclosed. A battery is fully charged using conventional CC-CV techniques and subsequently is maintenance charged by applying a first maintenance voltage to the battery for a first predetermined time period. If desired, a second maintenance voltage may be applied to the battery for a second predetermined time period. An apparatus for maintenance charging a battery utilizes a timer and a charge controller to apply a maintenance voltage to a battery for a predetermined time period.

Abstract: A battery charging device which charges a plurality of batteries includes a charging part which supplies a charging current, and a control part which controls the charging part so that the batteries are serially charged one by one and a supplemental charge to the batteries is then performed in parallel. The control part calculates a charged capacity for a first one of the batteries and thus determines a timing in which serial charge is switched to a second one of the batteries on the basis of the charged capacity.

Abstract: A method for charging a rechargeable battery pack includes providing a charger having first and second charging processes, and manually selecting one of the first and second charging processes. The charging method may include a step for indicating status or end of the selected one charging process. The first charging process may include the steps of providing a fast charging current, indicating end of the fast charging current and providing an equalization current. The second charging process may include the steps of providing a fast charging current, subsequently providing an equalization current and indicating end of equalization current. The second charging process may also include a temperature checking step. Further disclosed is a battery charging apparatus including a charger for charging a battery and having first and second charging processes, and a switch connected to the charger for manually selecting one of the first and second charging processes. The charger may include a microprocessor.