Battery C-rate

Battery C-rate describes charge or discharge power compared with battery capacity. A 1C discharge means a battery is being discharged at a rate that would empty its usable capacity in about one hour, before real-world losses and system limits. For example, a 10 kWh battery at 0.5C is charging or discharging at about 5 kW, while 1C would be about 10 kW. Home battery datasheets often show capacity in kWh and charge or discharge limits in kW rather than printing a C-rate, so the published kW limit is part of what decides how quickly stored energy can be used or replaced. Very high C-rates can increase losses and stress, so the safe working rate depends on the battery system and its published operating limits.