An internal short-circuit detection method for a battery cell of a battery pack is determined using a battery cell charge balancing resistor and switch. The switch is used for connecting or disconnecting the battery cell charge balancing resistor to the battery cell. Evolution of discharging of the battery with the battery cell-charge balancing resistor connected to the battery cell is monitored to measure an internal short-circuit resistance of the battery cell for estimating the state of the internal short-circuit.

A battery module charging and discharging control method comprising: determining the charging priority of battery modules in a battery system; raising the charging priority of the battery modules that are more difficult to unload, load, and/or replace; lowering the charging priority of the battery modules that are easier to unload, load, and/or replace; causing the battery modules with higher charging priority to take precedence over the battery modules with lower charging priority during the charging control of the battery modules; determining the discharging priority of the battery modules; raising the discharging priority of the battery modules that are easier to unload, load, and/or replace; and lowering the discharging priority of the battery modules that are more difficult to unload, load, and/or replace; causing the battery modules with higher discharging priority to take precedence over the battery modules with lower discharging priority during the discharging control of the battery modules.

Provided is a power storage apparatus, including: series circuits, the series circuits being formed of first coils and first switching elements, the first coils and the first switching elements being connected to a plurality of battery units in parallel; second coils electromagnetically coupled to the first coils; second switching elements connected to the second coils in series; a capacitor inserted between two common power source lines for commonly supplying voltage to both ends of the series circuits of the second coils and the second switching element related to the plurality of battery units; and a control unit that supplies a control pulse signal to the first switching element and the second switching element for equalizing voltage of each of the plurality of battery units, in which an amount of charge obtained by dividing an amount of transferred charge necessary for eliminating a voltage difference between the first battery unit and the second battery unit into 10 or more is transferred by switching operations of the first and second switching elements.

An energy storage apparatus includes a plurality of energy storage devices connected in series, a voltage detection circuit that detects voltages of the plurality of energy storage devices, and a discharge circuit that discharges the energy storage devices individually, and a BMU having a control unit, in which the control unit discharges only an energy storage device having a highest voltage among the plurality of energy storage devices. Further, charging is stopped when a first duration elapses in a state that a cell voltage of the energy storage device having the highest voltage exceeds a first voltage threshold, or charging is stopped when a second duration elapses in a state that the cell voltage of the energy storage device having the highest voltage exceeds a second voltage threshold.

When it has been determined according to a voltage detected by a voltage detecting unit 31 that a voltage detection line 23 between a focused-on battery 21 and the voltage detecting unit 31 has been broken, operations of each of switches 22 are controlled to separate a battery module 2 that includes the voltage detection line 23 from a power supply apparatus 1. When it has been determined according to the voltage detected by the voltage detecting unit 31 that the focused-on battery 21 has been overcharged or overdischarged, power input to, or output from, every battery module 2 is limited.

Cell balancing aims to prolong the battery operating life by equalizing the Electro Motive Force (or Open Circuit Voltage) of the participating cells. Even perfectly balanced cells though will exhibit different output voltages because of differences in their internal impedances. The difference in voltage will depend on the load current frequency and intensity. A method is described for re-distributing charge in such a way so when the worst (from the point of view of voltage spread) possible load conditions occur, cells will have similar outputs and none will cross the under-voltage threshold causing a premature shut down of the battery.

A battery system and a method for determining an open circuit fault condition in a battery module are provided. The method includes measuring a first voltage between first and second electrical sense lines while a first transistor in a first cell balancing circuit is turned off, and measuring a second voltage between the first and second electrical sense lines while the first transistor is turned on. The method further includes retrieving a first resistance value from a table stored in a memory device. The method further includes determining a first cell balancing current based on the first and second voltages and the first resistance value. The method further includes determining a first open circuit fault condition between the first battery cell and the first cell balancing circuit if the first cell balancing current is greater than a first threshold current.

The battery management system comprises: a battery management unit, configured to receive status information of a battery module and status information of a battery pack, and transmit a control instruction to cell measurement circuits; the cell measurement circuits, configured to collect the status information of the battery module, transmit the status information of the battery module to the battery management unit, receive and execute the control instruction transmitted from the battery management unit; sensing units, configured to collect the status information of the battery pack, and transmit the status information of the battery pack to the battery management unit; wherein a wireless communication unit is disposed in the battery management unit, and a wireless communication unit is disposed in at least a portion of the cell measurement circuits and/or at least a portion of the sensing units.

A battery management system for monitoring battery cells of an uninterruptible power supply (UPS) coupled to a medical imaging load. The battery management system includes a first slave configured to obtain an operating parameter of a first battery cell. The first slave is configured to determine health of the first battery cell based at least in part on the operating parameter. The first slave is configured to generate a signal indicating the health of the first battery cell to communicate serially, via at least a second slave, to a master.

A method and system for providing pulsed power and data from a main control unit to slave units via a first bus. The main control unit has an AC signal generator for providing a plurality of first pulses (P1) on the bus for providing the power to the slave units. Each slave unit is AC-coupled to the bus via a first series capacitor arranged for converting the first pulses (P1) into second pulses (P2). Data communication from the main control unit to the slave units is established by modulating the first pulses (P1), and by demodulating the second pulses (P2). The modulation may be based on Pulse Position Modulation, Pulse Width Modulation, Pulse Count Modulation, Pulse Amplitude modulation. Zero, one or more bits may be communicated per first pulse. Optionally the slave units may communicate to the main control unit via a second bus.