You could use an inverter. I have a small inexpensive coleman one that I take camping that would work. Kind of on the same subject I decorate an old car in my front yard every year with lights. Last year it was the 1940 1/2 ton. This year I have the lights on my 1953 Cadillac Fleetwood. I put 35 strands of lights on it and you can see it over a mile away.
