The purpose of having a battery in a car is to provide power to the starting motor and for ignition and lighting. The most common type of car battery is the flooded lead acid battery and it is referred to as SLI or starting-lighting-ignition battery. This type of battery can supply a huge rush of current to the starter motor and it can also be quickly recharged through the alternator. However, this type of battery is not suitable for deep discharge and if it is left unused, crystal and salt formation between the plates short out connections and the battery goes dead.

Types of Car batteries

• The most common type of car battery is the most basic flooded lead acid battery. Electrolyte can spill or evaporate and it needs topping up from time to time. A further development on this is a sealed maintenance free battery that will retain the electrolyte. Another type is the VRLA battery or the valve regulated lead acid battery. These car batteries are sealed to prevent electrolyte loss and only have leak proof vents to allow gases to escape.
• Some manufacturers have introduced absorbed glass mat or AGM technology where electrolyte is absorbed by the glass mat and this means the battery can be mounted sideways without fear of spillage or electrolyte loss.
• Though not commonly used, gel batteries, totally sealed and maintenance free, can also work as car batteries. Instead of a liquid electrolyte, the electrolyte is bonded to a gel and the battery is sealed.
• Some manufacturers have introduced batteries based on Calcium technology. Normal batteries have lead plates with a percentage of antimony. In calcium technology calcium is used along with lead for the positive or negative plates or both. Car batteries with calcium technology are said to have low self discharge, deliver high performance and are maintenance free.
• Some manufacturers, like Bosch, have gone for silver-lead alloy, claimed to give superior performance across all parameters like corrosion resistance, extended life and maintenance-free performance.

Care of Car batteries

If you are using normal flooded lead acid type batteries, which are also the lowest priced car batteries , you can expect good performance provided you take good care. You will need to top up the electrolyte at periodic intervals. Check if the level has fallen below the line marked on the container and then top up with distilled water or mild solution of sulfuric acid. Before you add acid, have pH level checked. Another thing is the battery must never be left unused without being charged. If you do, sulphation takes place and shorts the plates, resulting in a dead battery. Some service centers carry out desulphation but this is not entirely successful in restoring batteries. Keep the exteriors, especially the areas around the terminals dry. Terminals should also be covered in petroleum jelly to prevent fumes from corroding connectors and wires.