This question is similar to this one in the sense that I have my amateurish Leyden jar and I'm supplying ~7.5v from 5 batteries (~1.5v each) in series.
Some details and facts after experimenting:
- The brown wire is touching the water with salt inside the bottle and is connected to the lower voltage side of the battery
- The red wire is touching the aluminium and the higher voltage side of the battery
- If I use a multimeter touching the aluminium and the water, I get my ~7.5v, as expected
- If I remove the wires touching the battery and measure the voltage, there is none
- If I remove the wires touching the battery while the probes of the multimeter are connected I can see the voltage drop very very quickly.
- Making some calculations I estimate that the jar has around $ ~1.1pF $
Then I decided to connect the circuit with the led that you can see in the figure. A similar circuit with a capacitor $ 220 \mu F $ attached makes the led fade-away instead of switching off when I remove the battery. So I've been trying to see the same effect using the Leyden jar to convince me that it actually holds some charge.
However as soon as I separately the brown and red wire connected between the bottle and the batteries the led switch off without fade-away effect.
Does anybody know what could affecting the performance of my Leyden jar?