Magnum Energy MS4448PAE 48V Pure Sine Wave Inverter 4400 Watts
I bought one of these a couple years ago, and it's been working perfectly ever since!!! last I knew Expressbatteries.com has them for $1,800.00 bucks with a coupon code you type in at checkout. \\"LESS20PERCENT\\" or something similar to that.  This unit puts out 120/240 so it works great for backup power in a house and 4800W is plenty of capacity for most homes.