It is the ratio between the output and input capacity when the cell is discharged at a certain condition. It can be calculated by the following formula:
Charge efficiency=(discharge current × the time of discharge to end voltage / charge current × charge time) ×100%
Some of the input energy can transform the active material into charge status; some is consumed to produce oxygen in subsidiary reaction. The charge efficiency is affected by charge speed and ambient temperature. During charging the current must be defined in a certain range, too heavy or too small current can bring low charge efficiency. Because of self-discharge the battery can’t be fully discharged. |
