Discharge rate

Discharge rate describes how quickly a battery is being discharged compared with its usable capacity. It is usually expressed as a C-rate, or inferred from a discharge-power limit in kW or a discharge-current limit in amps. A 0.5C discharge rate means the battery is discharging at about half its capacity per hour, so a 10 kWh battery discharging at 5 kW is roughly at 0.5C before losses and manufacturer limits. Home battery documents may state the practical limit as maximum discharge power, peak or continuous output, maximum discharge current or a control-app discharge limit rather than a printed C-rate. The figure should be read with battery capacity, inverter output limit and manufacturer conditions because a system may reduce discharge near empty, outside ideal conditions or when battery-management controls restrict output.