This battery is very useful, cheap, and easy to make.
It uses simple materials, materials that can be found in everybody's fridges (coke), unwanted electrical appliances (copper), and the kitchen (aluminium which can replace zinc). This can significantly reduce the time needed to go down to the store to buy batteries. And it's much cheaper too, considering that there would be no other use for the unwanted electrical appliances, copper can be easily gotten from the cables inside it, and coke and aluminium is in everybody's houses too!
Areas for further study:
We can further study on what can increase the voltage the coke is producing now. Increasing the voltage produced means the same can of coke can produce more voltage for more things, and it can last longer.