1. The coulometric capacity, the total Amp-hours available when the battery is discharged at a certain discharge current (specified as a C-rate) from 100 percent state-of-charge to the cut-off voltage. Capacity is calculated by multiplying the discharge current (in Amps) by the discharge time (in hours) and decreases with increasing C-rate.
2. The battery capacity is a measure (typically in Amp-hr) of the charge stored by the battery and is determined by the mass of the active material contained in the battery. The battery capacity is the maximum amount of energy that can be removed from the battery under certain conditions.
http://web.mit.edu/evt/summary_battery_specifications.pdf (1.); http://pvcdrom.pveducation.org/BATTERY/capacity.htm (2.)
Author: Frithjof Kühnert