The mAh stands for milli-Ampere-hours and indicates how much electric charge the battery can provide. For example, if you discharge your battery through a circuit that requires 1 milli-Ampere of current it will last 800 hours before the battery runs down. If you discharge it through a circuit that requires 1 Ampere, the battery will last only 0.8x60 = 48 minutes.
LeeH
(published on 10/21/2009)