Depth of Discharge (DoD)

Depth of discharge (DoD) is the share of a battery’s capacity that has been withdrawn, so a battery at 30 percent state of charge is at 70 percent depth of discharge.

Battery warranties limit the DoD each cycle because deep cycles age cells faster than shallow ones. An energy management system respects those limits by holding a reserve at the bottom and sometimes a ceiling at the top of the range. The usable capacity quoted for a storage system is the nameplate capacity multiplied by the allowed depth of discharge.