What you need to make a fruity clock or torch:
Connecting leads and crocodile clips
LED boost or LCD clock with leads
4 Lemon quarters (or any other fruit)
4 Iron nails
4 Shiny copper coins (2p or 1p)

How to make a fruity clock or torch:
1. Insert the iron nail and the copper coin into one of the lemon segments ensuring that they do not come into contact with one another.
2. Connect this to the object to be powered, does it work? This is a single cell.
3. Try connecting several cells together in series or in parallel to produce a battery.
After each cell is added to the battery see if you have enough power.
It might be that lemon cells in both series and parallel are needed.