Battery Backup Resources

Battery sizing worksheet (calculation tool)
URL: http://www.alphasolar.com/alpha_solar_085.htm
Widernet: Backup Power Considerations
URL: http://www.widernet.org/DecisionMakers/misc/backuppower.htm
Selecting an inverter for a solar or battery backup system
URL: http://www.windsun.com/Inverters/Inverter_selection.htm
Battery University
URL: http://www.batteryuniversity.com/
Everything you ever wanted to know about batteries!