Bacteria powered batteries use the chemical energy generated by bacteria, and convert it into electrical energy using a relatively simple mechanism. Like most batteries, a bacteria powered battery has an anode (the negative end) and a cathode (the positive end). In addition to the anode and cathode, a bacteria powered battery also has a membrane capable of filtering electrons (anions) and protons (cations) produced during the chemical breakdown of substances by bacteria.
Once the bacterial breakdown starts producing ions, the anions are transferred from the cathode compartment via an external circuit and the protons are sent to the cathode from the anode. In a nutshell, the chemical energy generated by bacterial activity is converted to electrical energy.