Rechargeable battery systems and rechargeable battery system operational methods are described. According to one aspect, a rechargeable battery system includes a plurality of rechargeable battery cells coupled between a plurality of terminals and charge shuttling circuitry configured to couple with and shuttle electrical energy between individual ones of the rechargeable battery cells, and wherein the charge shuttling circuitry is configured to receive the electrical energy from one of the rechargeable battery cells at a first voltage and to provide the electrical energy to another of the rechargeable battery cells at a second voltage greater than the first voltage.

A smart cell, comprising: a positive terminal; a negative terminal; a switching circuit which is arranged to select between a first switching state in which an energy storage device is connected between the positive terminal and the negative terminal and a second switching state which bypasses said energy storage device; an inductor provided between the positive terminal and the output of the switching network; and a controller arranged to monitor the voltage across the inductor and arranged to control a duty cycle of the switching circuit based on the magnitudes of voltage changes detected across the inductor. By monitoring and analysing the magnitude of voltage changes across the inductor, the controller determines the states of charge of other series connected smart cells without any communication between cells. None of the smart cells need to transmit information on their states of charge to other smart cells in the string as each cell can sense information about the other cells from the voltage changes on the inductor. By analysing the voltage across the local sense inductor, the average state of charge of a series string of smart cells can be obtained and compared to the state of charge of the local smart cell to determine how the duty cycle of the local smart cell should be modified to synchronize its state of charge with the series string. The magnitude of the voltage change across the inductor is related to the state of charge of the cell that just switched in or out of the string.

A battery management system for a battery comprising at least one lithium sulphur battery cell. The battery management system comprising: a charging module operable to charge a lithium sulphur battery cell of the battery by delivering a pulsed charging current to the battery cell and to vary the duty cycle of the pulsed charging current so as to reduce the duty cycle of the pulsed charging current during charging of the battery cell.

A storage battery control device for controlling an energy storage system including storage battery rows connected in parallel, each of the storage battery rows having a plurality of storage batteries connected in series and bypass units each of which bypasses corresponding one of the storage batteries, and a switching unit that switches connection and disconnection of the storage battery rows. The storage battery control device executes: charging processing of charging the storage battery rows connected in parallel, first detection processing of detecting a fully charged storage battery during execution of the charging processing, second detection processing of detecting a storage battery having a highest potential among the storage batteries being charged in another storage battery row different from the storage battery row including the fully charged storage battery, and bypass processing of bypassing the storage battery detected in the first detection processing and the second detection processing.

The present disclosure relates to a battery management device for balancing state of charges (SOCs) of a plurality of battery cells while maintaining a substrate temperature of a substrate to which a balancing resistor of each of a plurality of battery cells is mounted to a reference temperature or below. Since the substrate temperature is maintained at the reference temperature or below by controlling the duty cycle of a balancing switch, it is possible to prevent components included in the battery management device from being overheated and damaged due to the heat generated during the balancing process.

A battery control unit includes a plurality of battery units, a charger configured to charge a battery, a controller, and a charging controller. Each of the plurality of battery units includes a switching unit. The switching unit is configured to switch between a connected state where the battery configured to be located in the same battery unit as that of the switching unit is connected in series with the battery configured to be located in an adjacent battery unit, and a non-connected state where the battery in the same battery unit as that of the switching unit is disconnected from the series connection with the battery in the adjacent battery unit.

A battery charging circuit for charging batteries includes a first switch connected in series between a first pole of a power supply and a first pole of the first battery cell, a second switch connected in parallel between the first pole of the first battery cell and a second pole of the first battery cell configured to adjust a size of a current applied to the first battery cell, a third switch connected in parallel between a first pole of the second battery cell and a second pole of the second battery cell, the third switch being configured to adjust a size of a current applied to the second battery cell, and a fourth switch connected in series between the second pole of the first battery cell and the first pole of the second battery cell.

A voltage measurement unit measures voltages of the plurality of cells connected in series. A plurality of discharge circuits are connected in parallel to the plurality of cells, respectively. A controller controls, based on the voltages of the plurality of cells detected by voltage measurement unit, the plurality of discharge circuits to make the voltages or capacities of the plurality of cells equal to a target value. The controller determines a number of cells to be discharged among the plurality of cells in accordance with an allowable temperature of a substrate having the plurality of discharge circuits.

A battery control unit includes a plurality of switching units, a first controller, and a plurality of bidirectional voltage converters including a ground terminal, a first, and a second input-output terminal. Each of a plurality of battery packs connected in parallel to each other includes a plurality of batteries connected in series with each other. The plurality of switching units are disposed corresponding to the plurality of batteries respectively, and are configured to switch between a connected state where a corresponding battery among the plurality of batteries is connected in series with non-corresponding battery among the plurality of batteries and a non-connected state where the corresponding battery is disconnected from series connection with the non-corresponding battery.

An open contactor bypass system for a battery is disclosed. The battery system has a positive and a negative output terminals, a battery management system, and a latching contactor in series with the positive and negative terminals. The latching contactor is operable between an open state and a closed state, under control of the battery management system. The open contactor bypass circuit may permit charging of the battery when the battery is coupled to a battery charger and the latching contactor is in the open state. The open contactor bypass circuit may comprise a bypass circuit disposed across the latching contactor for permitting charging current from the battery charger to flow through the bypass circuit, to bypass the open state contactor and charge the battery.