A plurality of storage batteries are divided into a plurality of storage battery blocks. A useful life of each of the storage batteries is shorter than the project life. Total capacity of the plurality of storage batteries is equal to or greater than the product of capacity required for a project and a ratio of the project life to the useful life. The project life is divided into a plurality of periods. For each of the plurality of periods, a rest storage battery block is selected from the plurality of storage battery blocks in rotation, the rest storage battery block is rested, and an operational storage battery block is operated. The sum of actual operating time of each of the storage battery blocks and equivalent operating time of each of the storage battery blocks is prevented from exceeding the useful life during the project life.

A system is disclosed for charging (recharging) and discharging a battery pack comprising a plurality of battery cells. The system may execute an iterative process of monitoring a frequency corresponding to the minimum impedance value of the battery pack or cell(s) of the pack and adjusting the charge energy signals applied to the battery pack. In some instances, taps may be provided within the battery pack to monitor the frequency response to the charge energy signal for one or more cells of the battery pack. In other instances, the battery pack as a unit may be monitored iteratively. This process may maintain a relative charge balance across the cells of the battery pack, decrease the time to recharge the battery pack, extend the life of the pack, optimize the amount of current charging the battery pack, and avoid energy lost to various inefficiencies.

In a storage system including a plurality of battery units, the charge/discharge amounts of the battery units are determined by predetermined computation using the state of charge (SOC). The predetermined computation includes allocating a larger discharge amount to a battery unit higher in SOC, out of the battery units, in the discharge mode, and allocating a larger charge amount to a battery unit lower in SOC, out of the battery units, in the charge mode.

The power supply device is provided with: a battery pack that comprises a plurality of battery units each of which includes a battery, a first terminal and a second terminal; a capacitor connected in parallel with the battery pack; and a current adjusting circuit that includes a load and a switching device for controlling a current to the load and adjusts a current from the capacitor to the battery pack. When a battery that has reached an upper limit voltage is detected during charging the battery pack, between control for closing a first path that connects the first terminal to the positive side of the battery and control for opening a second path that connects the first terminal to the second terminal and negative side of the battery, the power supply device causes the current to flow to the load to adjust the current flowing to the battery pack.

An electric power supply system includes an alternating current electric power supply circuit that converts direct current electric power of a first direct current sweep unit including a battery string into alternating current electric power using a first inverter and outputs it, and an alternating current sweep unit that includes a U-phase battery string, a V-phase battery string, and a W-phase battery string that are Y-connected. Output densities of batteries of the battery string are higher than output densities of batteries of the alternating current sweep unit. Alternating current electric power is output from the alternating current sweep unit and the alternating current electric power supply circuit, and after a predetermined period elapses, the output of the alternating current electric power from the alternating current electric power supply circuit is stopped.

A storage battery control device for controlling an energy storage system including storage batteries connected in series, bypass units that bypass the storage batteries respectively, and a current sensor that detects a charge and discharge current flowing from or into the storage batteries. Each of the bypass units includes a bypass line that bypasses the storage battery, a bypass switch that connects and cuts off the bypass line, and a cutoff switch that connects and cuts off the storage battery. The storage battery control device is configured to detect a zero current state in a case that both the bypass switch and the cutoff switch are in a cutoff state in at least one of the bypass units, and perform offset correction of the current sensor based on an output of the current sensor when the zero current state is detected.

A battery management device that manages a battery includes: multiple voltage detection circuits each connected to a corresponding one of a plurality of battery cells; and multiple discharge circuits each connected to a corresponding one of the battery cells. The battery management device causes the battery cell whose voltage difference from a reference voltage is equal to or greater than a predetermined first threshold and less than a second threshold that is greater than the first threshold to be discharged while a system of the vehicle is stopped, and causes the battery cell whose voltage difference is equal to or greater than the second threshold to be discharged at least either while the system is stopped or while the system is in operation.

A cell equalization system includes: a battery including a plurality of chargeable cells connected in series and mounted on a vehicle; a battery ECU configured to control the battery; an equalization circuit configured to perform equalization of remaining capacity variation of the plurality of cells; and an equalization control unit configured to control the equalization circuit. The battery ECU is configured to calculate the remaining capacity variation at startup of ECU in which the battery ECU changes from a sleep state to a startup state. The cell equalization system is configured to execute first equalization processing for performing the equalization when the battery ECU is in the startup state, and second equalization processing for performing the equalization when the battery ECU is in the sleep state.

A controller, a system including such a controller, and a method for controlling discharging of a plurality of battery packs are provided. The controller includes one or more processor and at least one tangible, non-transitory machine readable medium encoded with one or more programs configured to perform steps to minimize a corresponding voltage gradient versus charge of each battery pack to be below a predetermined threshold, and calculate a respective discharging share of each battery pack based on the charge and the voltage in an updated curve of voltage versus charge of each battery pack and the total power demand. The controller provides signals with instructions to the plurality of battery packs and/or the one or more power converters for discharging power from the plurality of battery packs based on the respective discharging share of each battery pack and/or keeping a certain battery pack idle.

A battery abnormality detection device that: for an equalization circuit including a discharge circuit provided with a switch that, in a case of being switched ON, causes a battery cell to discharge, and including a detector connected to the battery cell in parallel to the discharge circuit so as to detect a voltage of the battery cell, acquires a first voltage in a case in which the switch has been switched OFF and a second voltage in a case in which the switch has been switched ON, as detected by the detector, and estimates, from a detected value of one of the acquired first voltage or second voltage, an estimated value of another of the acquired first voltage or second voltage, and determines whether or not an abnormality has occurred in the equalization circuit based on the detected value and the estimated value.