Discharge Rate

The battery discharge rate “C” is the amount of current that would completely discharge the total capacity of a battery in one hour.  A 1C rate means the battery will discharge in one hour, a 0.5C rate in two hours, and a 2C rate in 30 minutes, with the current drawn being equal to the battery’s amp-hour capacity multiplied by the C rating. A higher C-rate signifies a faster discharge, in other words, it delivers a higher power output for a given capacity (kWh).

Continuous discharge rate (C) is the maximum current a battery can sustain over a long period without damage, while peak discharge rate (C) is the maximum current it can deliver for very short bursts. Continuous discharge is for sustained performance, whereas peak discharge is for high-demand, short-duration power needs like accelerating or starting a motor.  When comparing C ratings with other batteries be sure they are referring to the discharge rate and not the charging rate.