Battery Discharge Rate

Battery Discharge Rate is the measurement of how much power is being extracted from a battery. It incorporates both the current being drawn multiplied by the time period over which the power is being drawn.

A common way of rating batteries is to cite their capacity as the amp-hour rating, shown as "AH". A battery rated for 4AH would theoretically be capable of supplying 4 amps for 1 hour, or 2 amps for 2 hours, or 1 amp for 4 hours, etc. Note that the entire capacity is not typically exhausted for practical reasons.

Another common method of referring to discharge rate is the factor "C" (for "capacity"). Specifications for secondary-cell (rechargeable) batteries will frequently refer to the C-rate for both charging and discharging. C is the amp-hour rating of the battery.