Right photo: Your battery supplies a voltage of 9 V because it contains 6 cells.

Left photo: A quartz watch is powered by a self-made "orange battery".

What you have to do:
* Press a bare zinc sheet (Zn) and a bare copper sheet (Cu) into each half of an orange.
* Connect these two cells to have an orange battery:
   The Cu sheet of the left cell is fixed to the Zn sheet of the right cell by a crocodile clip.
* The free Zn sheet is connected to the black wire of a small quartz watch*),
   the free Cu sheet to its red wire.
* If the orange battery has enough power it should be indicated by the display.

[*) These watches are available in electronic shops]