The motor vehicle battery is designed to produce a strong enough current to turn the starter motor. It can do this by utilising a large number of cells which are connected together. When the engine is running, a generator rotates feeding current back to the battery to recharge it.
The car battery consists of lead oxide and lead metal plates. These are immersed in sulphuric acid electrolyte. As the battery begins to generate a current, the two types of plate change to lead sulphate. When current is fed back into the battery, the chemical reaction reverses.
