A method, battery module, an energy storage device and a power management system is provided. The capacity of the module and energy storage device is determined during current balancing between cells of the module. The capacity is subsequently used to control power to and from the energy storage device to maintain the energy storage device within a predetermined range of the maximum capacity of the energy storage device. The determined capacity is used as a maximum capacity for the energy storage device.

A circuit assembly for forming and testing batteries connected in parallel and in series includes a parallel test management device (PTMD) that connects to each battery and includes a main relay and a current transducer in series and an auxiliary relay in series with a current limiting resistor, which are parallel to the main relay. Parallel battery groups are formed by connecting multiple PTMD-battery combinations and a voltage equalizer in parallel. Multiple parallel battery groups are connected in series. A high-current, high-density battery testing system (BTS) connects to a battery formation rack that uses a double-sided PCB and double-polarity edge connector sockets for receiving a battery tray on a PCB having an edge connector for forming and testing over 1,000 batteries. This smart battery tray replaces a bulky, complicated engagement system and reduces the requirement for BTS channels and cables substantially. An aging rack monitors battery voltage on the smart battery tray. The equalizers and BTS pass current through the batteries simultaneously. The current through batteries and the voltage drop across the current transducer are about zero at the end of charge and discharge. Battery capacity and coulombic efficiency are measured using CCCV charge and CCCV discharge rather than CCCV charge and CC discharge.

A method for equalizing capacities of electric storage devices that are connected in series in an electric storage device assembly charged and discharged by a charger/discharger includes charging/discharging the electric storage device assembly at a charging/discharging rate of 1 C or lower, individually measuring voltages of the electric storage devices, respectively, determining whether a time rate of change in voltage of one electric storage device of the electric storage devices has reached a time-rate-of-change reference value and then a time rate of change in voltage of another electric storage device of the electric storage devices has reached the time-rate-of-change reference value, and individually discharging, based on a determining result, the electric storage device by a discharging circuit provided separately from the discharger.

A battery control method includes detecting charge state information including a charge current, a discharge current, and an SOC of the battery, detecting whether the SOC of the battery reaches a predetermined reference SOC using the charge state information, and determining when the SOC of the battery reaches the reference SOC as a first reference time point and when the SOC of the battery reaches the reference SOC after the first reference time point as a second reference time point, calculating a charge capacity of the battery using a charge current from the first time point to the second time point and a discharge capacity of the battery using the discharge current, comparing a difference between the charge capacity and the discharge capacity, and determining that an internal short circuit of the battery occurs when the difference between the charge capacity and the discharge capacity exceeds a threshold value.

There is a request for charging and discharging of a lithium-ion battery with as less degradation as possible. In an operation using only binary values as in conventional technology, however, in a charged state in which the battery is used, there is a high possibility that the battery is used toward accelerating the degradation thereof. In a power distribution device for distributing power between a plurality of batteries and a plurality of customers, when distributing the power of the batteries to the loads of the customers, by being based at least on the degradation information of the batteries, the state of charge, and the temperature data of the batteries, a battery discharging function is achieved that makes the degradation of the batteries minimum.

Disclosed is a battery charge balancing device which includes: a charge-measuring unit that measures charge of a plurality of batteries storing power through a plurality of power converters connected with a plurality of input power sources; a mode-conversion parameter calculating unit that calculates mode conversion parameters for determining mode conversion such that the power converters operate in a power conversion mode for converting power or in a balancing mode for balancing charge between the batteries; and a control unit that controls power transmission path of the power converters by switching a plurality of switches connected between the power converters and the batteries in accordance with the calculated mode conversion parameters.

A battery management system includes: a battery which includes battery cells connected in series; diodes which are connected in parallel to the battery cells; a switch unit which includes switches respectively connected to the battery cells; a control unit which detects voltages of the battery cells and performs cell balancing; and sensing lines which connect the battery cells and the control unit, wherein the control unit measures a first upper voltage difference between each battery cell and an adjacent upper battery cell in a state in which the switches are turned off, measures a second upper voltage difference between each battery cell and an adjacent upper battery cell after turning on the switches for a predetermined time, and, when the second upper voltage difference is greater than the first upper voltage difference, determines that the sensing line of the corresponding battery cell is disconnected.

Methods, systems, and devices for power electronics-based (PE-based) battery management. A system may include a set of battery strings, where each battery string may include a set of battery modules, and where each battery module may include a set of battery cells. The system may also include a set of power converters, where each power converter may be coupled with at least one battery string. A power electronics-based (PE-based) BMS may provide one or more battery management functions for at least one corresponding battery string while also monitoring or controlling a corresponding power converter.

A vehicle having a battery pack with cells arranged in at least groups of two cells in series is disclosed. A controller balances the cells based on a change in voltage across the cells being different than an expected change in voltage. The expected value is based on a current and a time associated with charging or discharging the cells. A controller is disclosed that commands charging and discharging of the battery cells based on a difference between a voltage across the group and the expected value for the group. A method for charging and discharging a battery pack is disclosed. The voltage across a group of cells is measured and compared to an expected value. An imbalance in a cell attribute is estimated according to a difference between the measured voltage and the expected voltage. The voltage across each battery cell is not required.

Provided herein are energy source systems for a vehicle. One energy source system for a vehicle includes a battery having a plurality of cells coupled in series with one another and adapted to be coupled to an alternator of the vehicle. The energy source system for the vehicle also includes one or more ultracapacitors coupled in series with one another and adapted to be coupled to starting components of the vehicle. The battery and the one or more ultracapacitors are coupled to one another in a parallel arrangement, and a combined voltage of the battery cells is substantially matched with a combined voltage of the one or more ultracapacitors.