NOT a battery!
Well, been doing some reading and the Aluminum Carbon (or in my case copper) isn’t acting as a battery, its a fuel cell. The Aluminum is oxidizing releasing electrons, this is why it can work in open air and why it produces hydrogen in water. I’m still a little fuzzy on the exact chemical reaction; my chemistry is pretty lacking.
Carbon is non-corrosive and fairly nonreactive which is why it makes a good electrode, but can have a pretty high resistance which decreases the amperage. Winding a good no corrosive conductor (stainless steal or silver) through your carbon electrode will help decrease resistance. You can also use stainless steal or silver, but stainless steal will eventually corrode and have to be replaced and silver is expensive.
Yay for electro-chemical fuel cells. I figure a model with aluminum cans will provide a sufficient fuel source.