Don’t want to pack away all those fun colorful Christmas lights? Check out this informative writeup on how to use holiday lights with battery power. It was written primarily for the bulb based lights, but LED strings should work even better than the bulbed ones.
Remember that each bulb uses half a watt-hour per hour. So 12 bulbs use 6wH per hour. Our batteries store (8 batteries x 1.2V x 1800mAh = ) 17,280mWh, or 17 wH. Therefore our 17 wH battery pack will power this 6-watt strand for almost three hours.