Method and device for completely recycling residual electric quantity of to-be-scrapped battery

The invention is suitable for a method and a device for completely recovering the residual electric quantity of a to-be-scrapped battery, and belongs to the field of new energy battery recovery processing. The invention designs a method for completely recovering the residual electric quantity of a battery to be scrapped, and the method specifically comprises the following steps: carrying out the voltage sorting of the batteries, and connecting the batteries with the same voltage V in series; the battery Bn charges the energy storage battery B, and when Vn is smaller than Va, the battery Bn does not continuously discharge; the voltage Vn of the battery Bn is boosted, the battery Bn continues to charge the energy storage battery B, and when the voltage Vs is smaller than Va, the battery Bn does not have the boosting condition; the battery Bn is connected in series with the adjustable direct-current power supply and the energy storage battery B, and the energy storage battery B is continuously charged; and when