An electricity storage device includes a plurality of cell batteries C.sub.1 to C.sub.M serially connected; and a management module including a balance circuit that can selectively cause electricity to be discharged from each of the plurality of cell batteries, and a controller. The controller includes a current-voltage acquiring unit that acquires a charging current and the respective voltages of the plurality of cell batteries and a balance control unit that, if a determination condition and an execution condition are satisfied, determines a lowest-voltage cell battery having a lowest voltage among the plurality of cell batteries and controls the balance circuit such that electricity is discharged from the plurality of cell batteries other than the lowest-voltage cell battery for time periods in accordance with differences between the lowest voltage and the respective voltages of the cell batteries when the determination condition and the execution condition are satisfied.

A battery module comprising a plurality of battery cell units, each one comprising: a battery cell having a first pole and a second pole, and a switch circuit, comprising a plurality of switches, and a switch controller arranged to control the switches of the switch circuit to enter either of a first state, in which the battery cell is connected in parallel with a neighboring battery cell, and a second state, in which the battery cell is connected in series with a neighboring battery cell. The battery module is configured to control the switching between the first and second states on a probabilistic basis.

An energy storage system includes a rack having a space inside, a plurality of modules in the space of the rack, each of the plurality of modules including a plurality of battery cells arranged in one direction therein, and a sensing line along one side of the plurality of modules.

A high voltage battery module comprising a plurality of low voltage battery assemblies and a method for manufacturing a high voltage battery module are provided.

A power management device is a power management device that controls a temperature inside a housing in a power storage system that includes a power storage device including a storage battery and the housing for housing the power storage device. The power management device includes an acquisition unit that acquires status information indicating a status of the power storage system, a calculation unit that calculates a target temperature in the housing based on an allowable capacity deterioration rate of the storage battery, and an air volume control unit that controls an air volume of a fan provided in the housing based on the status information and the target temperature.

An arrangement for temperature measurement on a solid body includes an annularly closed elastic band, along the circumference of which at least two temperature sensors are arranged at a distance from one another, preferably in a manner distributed uniformly along the circumference of the annularly closed elastic band. The annularly closed elastic band preferably incudes an electrically non-conductive, thermally conductive and/or heat-resistant material. The arrangement for temperature measurement can further be arranged in a groove which runs around the solid body. The solid body may be, for example, a battery cell.

Provided is a battery pack comprising a plurality of batteries; and a plurality of memories that correspond respectively to the batteries and that each record deterioration information of the corresponding battery. Each set of a battery and a corresponding memory may be formed integrally as a battery cell. As a result, the deterioration information of each battery cell can be known even after the battery pack is disassembled.

A battery pack and charger platform including a voltage coupling circuit comprising an input that receives an input voltage and an output that sends an output voltage, a voltage monitoring circuit having an input coupled to the voltage coupling circuit output and an output, and a power source having an input coupled to the voltage monitoring circuit output, the power source input receives an input voltage representative of a charge instruction.

A battery cell comprises a battery cell enclosure made of a non-metallic material. First battery terminals arranged in the battery cell enclosure. Second battery terminals arranged in the battery cell enclosure. Electrolyte is located between the first battery terminals and the second battery terminals. C conductive portions are arranged adjacent to an outer surface of the battery cell enclosure, where C is an integer greater than zero.

A battery system includes a battery module, a housing, a gas conveyor, and a gas sensor. The battery module is interconnected between a first system terminal and a second system terminal by a plurality of high current connectors, and the housing includes: a plurality of exterior walls enclosing the battery module and the plurality of high current connectors; and a partition wall within the housing. The gas conveyor is configured to circulate a gas flow through a flow channel loop formed within the housing by the partition wall and the exterior walls, and the gas sensor is arranged in the flow channel loop and is configured to detect an excess concentration of a gas species in the gas flow.