Patent attributes
A secondary battery system includes an assembled battery that includes a plurality of blocks that are connected in series to one another. Each of the plurality of the blocks includes same number of cells that are connected in parallel to one another. A control device is configured to calculate an internal resistance ratio and a protection current. The internal resistance ratio is a value obtained by dividing the higher one of internal resistances by the lower one of the internal resistances of two of the plurality of the blocks. The protection current is a value obtained by multiplying the internal resistance ratio by a current value of the assembled battery detected by a current sensor. The control device is configured to perform the charge-discharge control based on the protection current.
