An estimation device 4 is provided with: an acquisition unit 41 for acquiring time-series data about an SOC of a power storage element; a specification unit 41 for specifying a fluctuation range of the SOC in the time-series data and an SOC representative value representing an SOC region in the fluctuation range; and an estimation unit 41 for estimating a shape change of the power storage element on the basis of the specified fluctuation range and the specified representative value.

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 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 condition monitoring apparatus includes a measurer configured to measure a charging current which is an internal current of a converter and is charged into a sub-battery, a charging voltage of the converter, and an ambient temperature of a vehicle, an impedance calculator configured to an impedance of the sub-battery on basis of a voltage and a current each measured by the measurer, and a determiner configured to determine a condition of the sub-battery by using the ambient temperature of the vehicle and the impedance of the sub-battery.

A battery condition monitoring apparatus includes a measurer configured to measure a charging current which is an internal current of a converter and is charged into a sub-battery, a charging voltage of the converter, and an ambient temperature of a vehicle, an impedance calculator configured to an impedance of the sub-battery on basis of a voltage and a current each measured by the measurer, and a determiner configured to determine a condition of the sub-battery by using the ambient temperature of the vehicle and the impedance of the sub-battery.

A method for recognizing contacting errors in a rechargeable battery pack. Each rechargeable battery of the rechargeable battery pack is connected in parallel to at least one further rechargeable battery of the rechargeable battery pack. The method includes: applying at least one current to the rechargeable battery pack; ascertaining at least one voltage that is present at the rechargeable battery pack, as a function of the applied current; determining at least one parameter based on the ascertained voltage; and comparing the parameter to a comparison variable.

A method for recognizing contacting errors in a rechargeable battery pack. Each rechargeable battery of the rechargeable battery pack is connected in parallel to at least one further rechargeable battery of the rechargeable battery pack. The method includes: applying at least one current to the rechargeable battery pack; ascertaining at least one voltage that is present at the rechargeable battery pack, as a function of the applied current; determining at least one parameter based on the ascertained voltage; and comparing the parameter to a comparison variable.

A battery temperature estimation method includes fitting, when a battery is in an offline state, a first function relationship according to corresponding admittances of the battery at different test temperatures, and obtaining a temperature distribution model of the battery according to the shape and the size of the battery, and determining a second function relationship corresponding to internal temperatures and a surface temperature by combining with the first function relationship. The second function relationship is used for estimating the internal temperature of the battery by using the surface temperature and the admittances of the battery.

A battery temperature estimation method includes fitting, when a battery is in an offline state, a first function relationship according to corresponding admittances of the battery at different test temperatures, and obtaining a temperature distribution model of the battery according to the shape and the size of the battery, and determining a second function relationship corresponding to internal temperatures and a surface temperature by combining with the first function relationship. The second function relationship is used for estimating the internal temperature of the battery by using the surface temperature and the admittances of the battery.

A battery control system includes a plurality of battery cells that are separately controllable as units of individual cells or groups of cells. Each controllable unit may be switchably activated or deactivated in the overall battery circuit, and one or more conditions of each controllable unit may be individually measured. Various techniques are disclosed for operating the battery control system to optimize or improve system performance and longevity.