Note: Consider the C5 or C20 Amp rating of a battery when choosing one. There are solar/battery web sites selling Batteries with Apparent High Amp Hour capacities advertised at the 100 hour rate (i.e. C/100) We don't believe the 100 hour rate is a practical listing for battery buyers. It just a way to make a battery look larger and better than it actually is (higher Amp Hour number).
See http://www.windsun.com/Batteries/Battery_FAQ.htm for a good overview of batteries for Renewable Energy applications