Fig. 1
From: Charge and discharge profiles of repurposed LiFePO4 batteries based on the UL 1974 standard
Standard charge and discharge processes of Li-ion battery. Step I (CC discharge): The battery is discharged at constant current \({I}_{c1}\) until the voltage drops to the cutoff voltage \({V}_{cut}\). Step II: Rest for the duration \({t}_{r1}\) without the current pass. The voltage gradually rises to \({V}_{r1}\). Step III-1 (CC charge): The battery is charged at constant current \({I}_{c2}\) until the voltage rises to the threshold voltage \({V}_{th}\). Step III-2 (CV charge): The battery is charged by maintaining \({V}_{th}\) until the current reaches the cutoff current \({I}_{cut}\). Step IV: Rest for the duration \({t}_{r2}\) without the current pass. The voltage gradually drops to \({V}_{r2}\).
