A circuit device includes a charging circuit configured to charge a battery and a control circuit configured to control the charging circuit. The battery is provided with a protection circuit of the battery that comes into a shutdown state when the battery is in an over-discharge state. The control circuit causes the charging circuit to increase the charging current from an initial current value larger than zero to start constant-current charging of the battery when the shutdown state of the protection circuit is released.

A portable power charger is provided. The portable power charger includes a port configured to connect to a cable configured to connect to a battery and a safety circuit. The safety circuit is configured to: a) determine that the port is connected to the battery via the cable; b) determine that one or more battery factors of the battery meet one or more corresponding battery thresholds; and c) determine that one or more power charger factors of the portable power charger meet one or more corresponding power charger thresholds. The portable power charger also includes a a resistance analyzer configured to measure a resistance of the battery and an alert generator configured to generate an alert to signal when the battery is faulty based on the measured resistance.

A method for extending the storage lifetime of a rechargeable battery located in a device is disclosed. The battery lifetime extension method includes providing a device that derives its power from a rechargeable battery. When the device is powered off by a user, a computer implemented program utilized by the device automatically powers up the device into a lower power mode upon expiration of a variable duration timer monitored by the computing unit that continuously repeats according to a programed duration cycle. The computer implemented program then evaluates a state of charge of the rechargeable battery, determines whether the state of charge of the rechargeable battery is above or below a variable programed threshold, and causes the rechargeable battery to remain in a low power state until a charge is applied to the rechargeable battery.

A battery storage system includes a status information measuring part configured to measure status information of a battery, a processor configured to determine a plurality of phase sections of the battery based on the status information and to determine an optimal charging pattern of the battery for each phase section, and a charging device configured to charge the battery based on of the optimal charging pattern.

This application provides a battery and a charging method thereof, a battery management system, and an electric device, capable of improving charging performance of the battery. The battery includes at least one battery cell and a battery management system. A positive electrode active material of the battery cell includes LiMPO.sub.4, and M includes element Mn and element Fe. The battery management system is configured to: control the battery to perform a first constant current charging until a voltage of the battery reaches a first cutoff voltage; control the battery to perform a constant voltage charging; and control the battery to perform a second constant current charging until the voltage of the battery reaches a second cutoff voltage, where the second cutoff voltage is greater than the first cutoff voltage.

Various systems and methods are provided for monitoring state of charge (SOC) of wireless headphones. In one embodiment, a method comprises initializing a state of charge (SOC) of the earbud battery based on battery voltage in response to transitioning from a non-charging mode to a charging mode of the wireless earbud. In another embodiment, a first system comprises a left earbud, a right earbud, and a charging case comprising a microcontroller unit that monitors a right earbud battery and a left earbud battery via the charging case. In another embodiment, a second system comprises a left earbud, a right earbud, and a charging case comprising at least one communication bus communicatively coupled to the left earbud and right earbud to compare and correct a total charge of the left earbud battery, the right earbud battery, and/or the charging case battery.

A circuit for controlling a voltage, including: a plurality of traction battery banks; a first switch K1, where a first terminal of the first switch K1 is connected to each of the plurality of traction battery banks; a drive circuit, where the drive circuit includes a three-phase inverter and a three-phase motor, where a midpoint of each of three-phase bridge arms of the three-phase inverter is connected to each of three-phase coils of the three-phase motor respectively, where a first busbar terminal is connected to a positive electrode of each of the plurality of traction battery banks and a positive electrode of a charging port, a second busbar terminal is connected to a negative electrode of each of the plurality of traction battery banks and a negative electrode of the charging port, and where the three-phase motor is connected to a second terminal of the first switch K1.

A novel power storage system is provided. The power storage system includes a secondary battery, a current measuring circuit, a voltage measuring circuit, and a control circuit. The secondary battery includes a negative electrode. The negative electrode contains graphite and silicon. The current measuring circuit and the voltage measuring circuit are electrically connected to the control circuit. The control circuit has a function of starting charge of the secondary battery. The control circuit has a function of performing a first arithmetic operation of calculating a voltage differential value of the amount of electricity of charge current of the secondary battery with the use of a current value detected by the current measuring circuit and a voltage value detected by the voltage measuring circuit, and has a function of performing a second arithmetic operation of detecting an extremum of the voltage differential value. The control circuit has a function of stopping the charge after a predetermined time elapses since the extremum is detected through the second arithmetic operation.

A power storage device includes a plurality of batteries connected in series, a cell balancing circuit configured to individually discharge the plurality of the batteries, and a controller configured to execute a cell balancing process in which operation of the cell balancing circuit is controlled so that at least one of cell balancing target batteries is discharged by a predetermined state of charge, the at least one of the cell balancing target batteries including the battery that is fully charged.

Disclosed is an electrified vehicle including a motor, a dual inverter having a first DC terminal connected to a first battery and a second DC terminal connected to a second battery, and connected to both ends of the motor, a charging terminal to which a charging voltage of an external charger is applied while the external charger is connected, and a plurality of switches forming a charging path for the first battery and the second battery depending on switching states.