HOW DOES MY CAR BATTERY WORK

We often encounter the terms, “My car battery is dead” or “I need to recharge my car battery” when it comes to fixing and maintaining cars. However, do we really understand how does a car battery work? By understanding its functions, we can be confident you won’t take this important item for granted no more.

To understand your car’s battery, it also pays to understand a bit about electricity. Electrons are negatively charged particles that can carry an electric current. When you hear references to positive and negative ions, you’re actually hearing references to the absence or presence of electrons. Electricity, in general, will flow from a positive to a negative terminal, and with the help of electrons. These terminals are hooked up to all the components of your car that require electricity to function, including your windshield wipers, central door locks, and your engine.

Inside each automotive battery are smaller cells, each of which have their own positive and negative terminal. Each cell has 8 overlapping metallic plates for each terminal, making a total of 16 per cell. These cells are coated with lead and completely soaked in a 35% sulfuric acid bath.
Sulfuric acid is a strong acid, which ensures the steady flow of electrons, and, which can therefore conduct electricity. When the battery discharges, the plate coating is present as lead sulfate. When the battery is being charged, the plate coating is present as lead oxide.
When you start up your car, your battery sends out electricity, which allows the acid bath to react to the chemicals in the battery plates. These plates primarily release electrons, which travel from the positive, to the negative side of the plate; and then go from one cell to the next.
In the first cell, electrons carry a charge of 2 volts. As they move to the next plate, they accumulate a total charge of 4 volts. By the sixth cell, the electrons will travel from the battery and into the car, and carry a total of 12 volts.

This is the basis for auto batteries having the label “12 volts”. A 12 volt surge is enough to get your engine started, although more amps may be required from your battery when you have to use your windshield wipers, air conditioning, central locks, or a high-output stereo system. Overcharging a car battery could lead to less water inside the cells, since the electronic reaction breaks down the water.

This could lead to higher levels of sulfuric acid in the battery allowing a highly corrosive “Acid Soup” to develop. Battery maintenance is required to replenish the lost water, preferably distilled to avoid adding impurities to the electrolyte.