The lead acid type of battery is the primary source of electricity for starter and alternator performance. It also serves as a reserve source of electricity for running the various electrical loads in the vehicle. Vehicles with larger engines require more cranking power and therefore need a larger battery than a smaller engine. Larger batteries can also be used in vehicles that are equipped with an abnormal amount of electrical accessories.
A properly maintained lead acid battery will last 3 to 4 years depending on environment and service usage. Batteries that are in vehicles that are in storage without periodic maintenance will have seriously depleted life expectancy. Proper battery maintenance in order to effectively harvest the longest life from starters and alternators is to be performed as follows.
Always keep the battery clean, both on the sides and on the top. Terminals and connections should be removed at a minimum of yearly, cleaned with the proper tools and re installed with anti corrosion material on the terminals and connections leading to the other components. There should never be any liquid or overflow on the surface area of the battery at any point in time.
The battery should always be filled to the proper level with distilled water. Usually most manufacturers ask the cells to be filled almost to the bottom of the plastic reservoir. This allows the optimum electrochemical reaction to take place without the danger of excess sulfide gasses being released. Also the battery should be properly held in place in the battery carrier.
A lead acid automotive battery is an electrochemical device. In other words, chemical reactions between materials inside the battery will cause electrons to circulate from atom to atom. As a result,an electrical voltage or pressure is developed. This pressure causes the production of electrons or a current. Any circuit forced backwards through the battery will cause a chemical reaction that will restore battery materials.
The electrochemical process in a battery is reversible. If the terminals of the battery are connected to a source of higher voltage than the battery itself, the electrons will flow backwards. When the current is reversed it causes another chemical reaction in the battery. The components in the battery are lead and lead peroxide. The cells can only be charged and discharged as fast as the electrons will move through a battery. Placing too high a voltage or forcing more voltage than what the battery can take, results in the formation of hydrogen and oxygen gasses.
This is both a dangerous and volatile scenario because the gases are vented outside the battery and are very explosive. Keep all sparks and flames away from any any battery at all times. Even the slightest spark can produce a potentially dangerous bomb that will surely spill a burning acid to all surrounding areas. A good understanding of the automotive battery and it’s purposes is necessary to the automotive repair technician of today.