Depth of discharge

Depth of Discharge (DOD) is an alternate method to indicate a battery's state of charge (SOC). The DOD is the complement of SOC: as one increases, the other decreases. While the SOC units are percent points (0% = empty; 100% = full), DOD can use Ah units (e.g.: 0 = full, 50 Ah = empty) or percent points (100% = empty; 0% = full). As a battery may actually have higher capacity than its nominal rating, it is possible for the DOD value to exceed the full value (e.g.: 55 Ah or 110%), something that is not possible when using state of charge.