Want to know How Car Batteries Work? The electric energy that batteries provide serves as another form of fuel to run cars. You need gas in the tank and a battery under the hood or your car just will not run. As obvious as that statement is, not to forget the importance of other components, we feel it is the simplest way to describe a car battery.
- Batteries provide the energy needed to start the motor, and they make their own energy using the charge current inside them. The battery has the ability to both generate and accumulate electricity. It achieves this by relying on reversible chemical reactions.
- All car batteries have two terminals; one is positive while the other is negative. Once attached under the hood, the battery sends power via linked cables to different sections of the car. Examples: radio, air conditioning, engine starter, etc.
- All batteries have six cells containing lead acid. These are the energy-producers. There are two electrode groups in each cell. Also, each cell is made up of eight overlapping metallic plates totaling sixteen per cell.
- When seen as a bunch, the plates look like a dense grid. If you want to generate more power, this grid’s surface area has to be bigger.
- The positive grid, linked up to the positive (red) side of the battery, is layered with lead oxide and is responsible for ushering electrons into the battery. The negative (black) grid, linked up to the negative side of the battery, is layered with lead and is responsible for releasing electrons.
- The plates inside each cell, in fact the cells themselves, rest in a chemical solution called a ‘bath’, which is made of 65% water and 35% sulfuric acid. The solution is therefore acidic, quite volatile, and dangerous.
- These potent chemicals undergo important reactions and in the process produce electricity. The reaction repeats until the battery is drained.
- The acid solution mentioned earlier act as electrolytes, which are conductors of electricity. In case of battery discharge (i.e., when it unloads electricity), the acidic solution interacts with the chemicals (lead oxide on the grid’s positive side and lead on the grid’s negative side) layered on the plates.
- These plates, being dipped in the electrolytic bath, give out electrons. As they race through the grids, electricity is produced.
- The electrons shift from the first cell containing the positive grid. They move into the negative grid in the same cell and make their exit. This process produces two volts.
- A chemical alteration takes places between the lead layers and lead oxide layers coating the electrodes. When the first cell’s electrons shift into the adjacent cell, another two volts is created. You will have a total voltage of twelve (hence the 12-volt car battery) at the end of the session when the electrons leave the final cell.
- The car’s battery can be considered fully loaded. It contains enough power to enliven the motor and perform engine cranking. Once sufficient power has been sent to get the motor started, your car will use its fuel reserves to keep the motor going while the battery caters to other sections of the car.
The alternator (also found inside the battery) distributes power for other electrical requirements, allowing the battery to keep itself powered. The alternator’s electrons race through the battery in the opposite direction (in through the negative and out through the positive). By reversing the chemical reaction, the battery recharges itself.
The electrons in the electrolytic bath return to normal and keep the battery charged, generating another 12 volts of electricity. If, say, the car lights are left on overnight the chemical reaction can move only in one direction, eventually draining or discharging the battery. If in this manner the battery fails to recharge itself, it will die.