The “C” rating (or burst rate) is the battery’s safe discharge limit rating as a function of capacity.
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For example: a “35C” battery means it can be safely discharged at a rate up to 20 times its capacity. For example a 3200mAh capacity battery with a 35C discharge rating can be discharged continuously at 112 amps (112000mAh) (35 x 3.2A = 112 amps).