Question: What chemicals do we share with a double AA battery that allow us to compare the energy in a human to a AA battery? And why an AA battery and not an A battery - are there less chemicals in an A battery?
Humans do naturally contain very small amounts of metals that you can also find in batteries (e.g. zinc is an essential element for human health). However people do not have AA batteries inside them! People do generate energy though – we eat food, which is oxidised inside our bodies to release energy. By comparing a human to a AA battery we are comparing the potential of both people and batteries to generate energy – although we do it in different ways!