I’ve built this unit to provide silent power during power outages that usually result from large thunderstorms and hurricanes in my area. It contains a marine deep cycle battery connected to a 1000 watt Black & Decker inverter. The inverter is mounted to the enclosure for the battery to make it convenient to store and move. During Hurricane Irene it was able to power the fridge, lights, networking equipment, and netbook for more then eight hours without interruption. I would eventually like to add in a built in AC charger, 12v outlet and small light to make this box even more useful when the grid is not available.