C-rate
PerformanceAlso known as: Charge Rate, Discharge Rate
C-rate describes the speed of charging or discharging relative to a battery's total capacity. A 1C rate means the battery charges or discharges its full capacity in one hour. A 0.5C rate takes two hours; a 2C rate takes 30 minutes.
For example, a 5 MWh DC block operating at 1C would charge or discharge at 5 MW. Most utility-scale BESS systems are designed for 1C or 2C operation. Higher C-rates generate more heat and can accelerate degradation, so they require better thermal management. The C-rate capability influences which grid services a BESS plant can provide — frequency regulation typically requires fast (high C-rate) response.
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