The energy stored in a simple cell is chemical energy. A simple cell is an electrochemical device that converts chemical energy into electrical energy. The chemical reactions taking place within the cell create a potential difference between the electrodes, and when a circuit is completed between the electrodes, electrons flow through the circuit, producing an electrical current. The chemical energy is stored in the reactants of the cell, which are typically stored in separate compartments within the cell until the cell is activated by connecting the electrodes. As the chemical reactions proceed, the reactants are converted into products, and the energy difference between the reactants and products is released as electrical energy.