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Topic: Potato and Lemon Batteries, etc. (Read 1 time) previous topic - next topic

dkl65

Hello!
I have some questions about potato and lemon batteries, etc.
Are they rechargeable? If yes, how much voltage is needed?
I used a nail and copper wire in a lemon. I produced 0.5V. The nail probably was not galvanized, because some people produced 1V.
What is their current capability? How many mAh (capacity)?
If a device consumes a steady 50mA from a 2500mAh battery, how long until the battery runs out? How to calculate?
When I put the nail and copper wire in vinegar, they began to rust, and the voltage was falling. I wiped away the rust, and the voltage returned to the previous state.
Thanks!

Grumpy_Mike

Quote
Are they rechargeable

No they are primary cells not secondary cells.

Quote
What is their current capability?

Chuff all, a few micro amps for a day or so.
The capacity over the drain will give you a first approximation although it willbe an over estimation.

Yes the voltage drops because the chemical reaction causing the voltage is inhibited by the reaction products. Wiping it causes fresh surface to be exposed. The energy required in wiping the contacts is much greater than the energy from the reaction.

dkl65

Quote from: Grumpy_Mike
Chuff all, a few micro amps for a day or so.

Then, how come some people can light LEDs with lemon or potato batteries?

Grumpy_Mike


dkl65

#4
Jun 22, 2012, 09:33 pm Last Edit: Jun 23, 2012, 04:06 pm by dkl65 Reason: 1
Of course you can light LEDs with potato/lemon batteries! Last year in school, one group connected 4 potato batteries in series, and lit up an LED somewhat.

Also...
http://www.youtube.com/watch?v=AY9qcDCFeVI
LED lights up at 5:03.

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