I have a small collection of hand crank lights going back to the 40's.

The only reliable ones are what I would call hand pumped. When you pump the light comes on, when you stop out it goes. No batteries or capacitors. Very simple.

When you need light they work, always. Can't put them down of course but low effort needed and the rhythm of pumping is slow.


I have discovered that many satellites now do not have batteries or any power store on board. This is because the battery is the main limit on the satellite's life and they also too often fail. The satellites are set into an orbit of continuous light or the operator puts up with intermittent, but easily predictable blackouts.