A car battery is a rechargeable battery that supplies electrical current to a motor vehicle. Its main purpose is to feed the starter, which starts the engine. Once the engine is running, power for the car's electrical systems is supplied by the alternator.
A typical car battery has six cells. Each cell has two plates, or grids: one is made of lead, the other of lead dioxide. Each cell can produce about 2-volts of energy. In most car batteries you have six cells, and therefore a 12-volt battery.
The plates are submerged in sulphuric acid that triggers a reaction between the two plates. In scientific terms, the acid acts as a catalyst.
This acid will trigger a reaction on the lead dioxide plate, causing the plate to produce two things: ions and lead sulphate.
The ions produced by the lead dioxide plate react to the adjacent plate to produce hydrogen and lead sulphate.
The result is a chemical reaction that produces electrons. The electrons race around the plates and generate electricity. The electricity flows out of the battery terminals to start your engine, turn on your headlights, and play the radio.
This chemical reaction is entirely reversible, which is why you can jumpstart your battery and continue to charge it throughout the duration of its life. By applying current to the battery at just the right voltage, lead and lead dioxide will form on the plates and you can reuse your battery, over and over again!
