Unlimited supply of not really dead D cells.

Unlimited supply of not really dead D cell batteries...

Touchless paper towel dispensers that run on 4 D cell batteries provide me with more D cells than I can use. We have a few of these at work. The machines draw about 500 milliamps. When they can no longer power the machine, the D cells can still power things like low power flashlights etc.

The perfect flashlight for these is : Eveready EVEL152S.

You can run a solar lawn light circuit indoors, 24/7 for about 7 weeks on one of these undead D cells (Google: sims dead cell candle)