Make a battery out of a beer can
 

http://www.metalectrique.com/pg003.html

I found this, I would be greatful if someone could find a more detailed description on how to make this yourself.

Re: Make a battery out of a beer can
 

Interesting. Haven't seen that one before.

One of the simplest methods is the lemon battery. :)

http://hilaroad.com/camp/projects/le...n_battery.html

If you juice the lemon, clean up the acid and use a decent cathode and anode, you can probably get more power out of it. I'd use a bunch of these in series to charge up some NiMh rechargable batteries. Might need a lot of lemons though, but nature provides. Acetic acid from vinegar might do it too, very cheap stuff and easy to obtain.

Re: Make a battery out of a beer can
 

Lemons are plentifull here, however this battery seems very inefficient. Apparently the idea with the beer can battery is that the aluminium is oxidized, and electricity is generated in the process. Similar to what happens when aluminium reacts with rust in thermite, but the energy is released very rapidly then and is not harnessed into electricity.

Re: Make a battery out of a beer can
 

Yeah, an acetic acid type battery is not going to provide very much current, here is an interesting video though.



If the aluminium oxidises, it may form an oxide layer and shut down the process, not sure how they get around that or if the oxide layer is a problem in the battery reaction.

Re: Make a battery out of a beer can
 

Yes I was thinking about that, I am not quite sure how it works chemically but apparently the battery could give about 100 mA of power for a week.