Lead acid car battery. This type of battery uses strong acids and heavy metals to store large amounts of electricity. The electricity is used in motor vehicles to provide the initial power to start the engine. Once the engine is running, the power from the engine is used to recharge the battery. This is a Blue Dynamic battery from Varta, used in a wide range of cars. This battery uses a lead-calcium-silver alloy to improve performance, an innovation introduced to the Blue Dynamic range in 1999. Varta, one of the world's leading battery manufacturers, was founded in Germany in 1904, and the car battery division was sold to the US company Johnson Controls in 2002.