$15 ChugPlug Battery Outlet Hack

Seriously, you could destroy stuff if you don't understand what the limits of this are. Proceed with caution if you try to make one. I'm probably only going to use it with 12V 2A or less switch mode power supplies and resistive devices. The low 80VAC output is a large concern because devices will need to pull 1.5X the current on the AC side to get the same power.