Battery C-Rate Calculator
Compute battery C-rate from power and capacity while accounting for optional SOC window and efficiency assumptions used in operational planning.
This simplified calculator does not model temperature, degradation, inverter clipping, or transient limits.
Examples
- 500 kW power, 1,000 kWh capacity, optional fields blank => Usable capacity: 1,000.00 kWh. Effective C-rate: 0.50 C. Equivalent full-power duration: 2.00 hours.
- 1,200 kW power, 2,000 kWh capacity, 90% SOC window, 95% efficiency => Usable capacity: 1,710.00 kWh. Effective C-rate: 0.70 C. Equivalent full-power duration: 1.43 hours.
FAQ
Why does C-rate change with SOC window assumptions?
A narrower SOC window lowers usable capacity, so the same power corresponds to a higher effective C-rate.
Should I use rated power or measured power?
Use measured power for operations analysis and rated power for specification comparisons; keep the choice consistent across scenarios.
Is this valid for both charge and discharge?
Yes. The same ratio applies; just document whether the power value represents charging or discharging operation.
Additional Information
- C-rate is expressed as reciprocal hours (C), where 1.00 C means full discharge in one hour.
- If SOC window is blank, the calculator assumes 100.00% usable depth of operation.
- If efficiency is blank, the calculator assumes 100.00% discharge efficiency for a neutral baseline.