automotive batteries are an example of a galvanic cell. this cell is created using lead (iv) oxide and lead, contained in a 4.2-5 m sulfuric acid solution. in the cells, lead (iv) oxide is converted to lead (ii) sulfate, and lead is converted to lead (ii) sulfate. this redox reaction produces a voltage that is then used to start the combustion engine in a motor vehicle. while the engine is running, an alternator is used to re-charge the cell using the energy generated by fuel combustion. the standard reduction potentials for the half-reactions used in this cell are: