Originally Posted by scottyt
sounds like a 800 watt cheapy microwave from walmart and a 1000 watt inverter might be better
That's what I used on an extended trip and it worked great. I literally used the cheapest microwave I could find and it ended up being one that was on sale at Walmart for under 50$us. Then I used one of those cheap inverters, also from Walmart to power it. Worked like a charm.
Now that I think about it, even the 100amp/hr batteries were from Walmart!
Edit - This is very similar to the microwave I bought, this one is 55$us but the one I bought was less because it was a promotional item.
Source: (I'm not posting the source because A) it should be obvious, and B) it is an advertisement)
One reason I wanted one with the knobs on it instead of electronic gwhiz is because when the microwave *dings* and it is finished cooking, it is also finished using electricity until you use it again.