Building Batteries

[KAE]

I've recently become interested in putting together home-made batteries after experimenting a little with galvanic cells. I was able to get over 3 volts with just a little construction repair wire, some copper wire, toilet paper and saltwater. I have heard of lemon juice is a good electrolyte as well. Does anybody have any other recipies?

 

[Grinhill]

One of the electronics store chains in australia used to sell an electronics kit with lots of fun projects for kids, one of the projects was a beer-powered radio, which I think comprised an electrolytic cell with beer as an electrolyte. (can anyone spot the problem here - "I just need a six-pack so I can listen to the radio, Dad")

Main problem with these cells is the current capacity is extremely limited, particularly when you take the volume into consideration.

Modern multi-plate technology with very small gaps between plates is something that's difficult to replicate at home.

 

[KAE]

Yeah that's true, I was just intrigued by the idea of using the saltwater to power a battery. You could run this juice produced by the salt water battery back into the salt water to to split the Hydrogen and Oxygen atoms through electrolosis and make clean hydrogen fuel from the water with the water itself as the power source!

 

[heathyoung]

That was the old Dick Smith 'Funway into electronics' book 1 IIRC - printed in the 1970's (and reprinted again and again and...)

Silver/copper Coins in lemons, softdrink etc etc is a pretty common one, if you get more advanced, nickel and cadmium with a NaOh (sodium hydroxide) electrolyte works well I hear You can even recharge it (no, I don't recommend doing rechargable (secondary) cells, the chemistry is far more complex).

 

[Drunkskunk]

I know you can make a battery from a can of coke and a pocket full of coins. it won't make much juice (no pun intended ) but it would power a small emergancy radio.

 

[dak664]

I know you can make a battery from a can of coke and a pocket full of coins. it won't make much juice (no pun intended ) but it would power a small emergancy radio.

US pennies have been copper-clad zinc since 1982. Sanding one side down to the zinc and stacking with electrolyte layers gives around 5 ma at 500 mv per coin. 5 or 6 will run an LED for a while.
Zinc is toxic, especially to dogs. It dissolves in stomach acid.

 

[KAE]

Cool, thanks for the info. So you can really make a battery and only spend a few pennies!