The general rule
of thumb is you use about 4 hours for the amount of time you average the panel puts out full power
for the day. So 6 amps times 4 hours is 24 amp-hours. If you want to get picky, they give two different amp specs on the spec sheet, short circuit and max power
transfer. So the actual amps that you will see at battery
voltage will be a little less. You don't have to worry about it since the number of hours is approximate and varies between 4 and 5 hours depending on where you live and who you talk to, this is just an approx number anyway.
If you were asking about appliances
, 1 two amp light on for 2 hours is 4 amp-hours.