Originally Posted by Doppy
Take a look at the power requirements for the heating pad versus what the inverter says it could supply. That's a good place to start.
Radio Shack's Web site lists a 350 watt model as the highest output inverter they sell. Sould be enough to run at least a small heating pad.
Except that when you run it at 350 watts you'll need to supply it with around 30 amps of 12 volt power. Which almost always means pulling a cable directly to the battery. Thankfully most of these use a lot less.
But look what Amazon found for me:
http://www.amazon.com/gp/product/B00...&s=hi&v=glance