Ans:
The amp-hour rating for a given
battery is the maximum amperage that can be drawn continuously until the
battery is completely discharged, flat, empty, drained, dead, over a specific
time period.
Battery manufacturers complete tests on their batteries to give them an Amp-Hour rating. A typical time period for a test is 20 hours, but it varies - batteries are tested over different periods, such as 24 hours, 75 hours, even 100 hours. But as you'll see below, a 100 Amp-hour battery tested over a 100 hour period (i.e. 1 amp drawn for 100 hours) will not have the same capacity as a 100 Amp-hour battery tested over a 20 hour period (i.e. 5 amps drawn for 20 hours). It turns out that if you drew 1 amp continuously from the 20 hour test battery, it would last for 110-120% longer than on the 100 hour test battery.
Suppose you have a 100 Amp-hour battery, tested over a 20 hour period. 100 Amp-hours divided by 20 hours = 5 amps. That means that the battery manufacturer claims the battery can sustain a 5 amp load for 20 hours until the battery is completely dead.
