A Method for Draining Leftover Energy From Waste Lead–Acid Batteries Prior to Recycling

In this study, a self-adaptive pulse discharge (SAPD) approach is developed and utilized to drain leftover energy from waste lead–acid batteries before entering the recycling process. This SAPD method was applied to find the optimal pulse frequency and duty cycle values for determining the discharge current from the batteries. Experiments were conducted using two parallel-connected Yuasa 12-V/6-Ah batteries. The energy recovered from the batteries was 54.7 kJ, and the corresponding recovery efficiency was 78.7%. The energy recovery efficiency could be improved to 80.9% by including three 15-min relaxation periods when the terminal voltage of the batteries reached the cutoff voltage of 10.5 V during discharge. The findings of this study could pave the way to a more sustainable future, even though major improvements in the recycling process are still required.