Battery abnormality detection system, battery abnormality detection method, and battery abnormality detection program

A battery abnormality detection method comprising:

• acquiring voltage data and current data of each of a plurality of cells in a battery pack including the plurality of cells connected in series, or voltage data and current data of each of a plurality of parallel cell blocks connected in series in a battery pack including the plurality of parallel cell blocks each including a plurality of cells connected in parallel;
• estimating dV/dQ indicating a differential value of a voltage with respect to a capacity of the each of the plurality of cells or the each of the plurality of parallel cell blocks for a constant-current charging period of the battery pack, based on the voltage data and the current data of the each of the plurality of cells or the each of the plurality of parallel cell blocks;
• calculating, at every constant-current charging period, a charged electricity quantity for a period from a first appearing peak to a last appearing peak of a plurality of peaks of dV/dQ of the plurality of cells or the plurality of parallel cell blocks, based on voltage transitions and dV/dQ transitions of the each of the plurality of cells or the each of the plurality of parallel cell blocks during the constant-current charging;
• and
• determining whether or not a micro-short circuit has occurred in the battery pack based on a change in the charged electricity quantity.

A non-transitory machine-readable recording medium that stores a battery abnormality detection program causing a computer to execute:

• a process of acquiring voltage data and current data of each of a plurality of cells in a battery pack including the plurality of cells connected in series, or voltage data and current data of each of a plurality of parallel cell blocks connected in series in a battery pack including the plurality of parallel cell blocks each including a plurality of cells connected in parallel;
• a process of estimating dV/dQ indicating a differential value of a voltage with respect to a capacity of each of the plurality of cells or each of the plurality of parallel cell blocks for a constant-current charging period of the battery pack, based on the voltage data and the current data of the each of the plurality of cells or the each of the plurality of parallel cell blocks;
• a process of calculating, at every constant-current charging period, a charged electricity quantity for a period from a first appearing peak to a last appearing peak of a plurality of peaks of dV/dQ of the plurality of cells or the plurality of parallel cell blocks, based on voltage transitions and dV/dQ transitions of the each of the plurality of cells or the each of the plurality of parallel cell blocks during the constant-current charging;
• and
• a process of determining whether or not a micro-short circuit has occurred in the battery pack based on a change in the charged electricity quantity.