Inverters are rated in watts.

Less than two watts for 100 mini lights.

I ran two six foot Christmas trees, about 5 100 light mini string and
four light strings off a 350 watt inverter at last years Festival of
Lights in Putnam and it didn't even breathe hard.

Have a freakin' ball with the lights. :)



Try closer to 50W for a string of 100 mini lights, unless they're the
LED type. I was a little surprised honestly, but last year I acquired a
power analyzer and ran around plugging in everything I could find in the
house. The Christmas tree with miniature lights on it was pulling around
350W, at which point I started checking individual strings. Incandescent
loads have a unity power factor, so you can measure the amp draw with
any cheap multimeter and use ohms law to calculate the watts.

The bulbs themselves use a lot less power than the larger old fashioned
C7 lights, but people tend to use so many more of them that they end up
not saving much power.