So I'm making a simple aluminum air battery with my friend for his class science project using a carbon cathode and aluminum anode.
It's basically a carbon rod wrapped with cellulose paper soaked in salt solution and wrapped in aluminum foil.

Problem is, for some reason all of a sudden, my battery doesn't generate any current. It was 2ma before but now....0. Wtf just happened?
I tried replacing the paper/aluminum with a new set of paper/aluminum but still nothing.

At first I thought the meter as low on juice but I changed the battery and the same problem is still there.
The only thing that could be wrong is maybe the carbon rod got changed some how but the carbon rod doesn't participate in the net reaction.....so I'M SO CONFUSEDDDD!!

 

...the carbon rod doesn't participate in the net reaction.....so I'M SO CONFUSEDDDD!!

No, but it can become fouled and no longer conduct electricity. Perhaps you could freshen it up with some 600 grit sandpaper, or maybe even just a good wipe with a paper towel.

 

hmm. So my voltage remained the same and my amperage decreased so that has to mean resistence increased since Voltage = Current X Resistence?

I already tried wiping it with a paper towel and still nothing happened.

 

The intrinsic property of emf stays the same but the extrinsic property of current depends on surface area and reactivity. Fouling is a kind of resistance standing in the way of the emf.