A regular preventive maintenance check on the batteries in your car is a necessity in ensuring proper and reliable starting and proper equipment must also be in place to handle the same properly. The safety measures involve switching off the engine and all the accessories before servicing the batteries and removing the cables that are connected to the negative terminal. Flammable hydrogen gas is generated when the batteries are charged, therefore, do not make sparks or smoke around the batteries, and charge them in an open place. Electrolyte has corrosive sulfuric acid and therefore protective safety glasses must be used and children must be avoided. Check the outside of the batteries, positive terminal, and cable clamp have not been damaged and test the batteries to see whether there is corrosion, loose connections, or cracks. In the event of corrosion, remove batteries, cleaning them in care not to touch the ground cable. Wash the cable clamps and terminals using warm water with baking soda solution and use safety goggles and gloves but make sure that all the places cleaned are rinsed with plain water. The battery tray is to be in good condition and it must not have hold-down clamp fasteners that are too tight without being too loose. To achieve the best results, in case cables were removed, the powertrain control module has to re-learn the idle and fuel trim strategy. It is possible to remove corrosion using a solution of water and baking soda and any damaged metal elements are supposed to be treated using a primer that is zinc-based and then painted. Discharged batteries should be charged with a slow rate preferably in the winter period with a charger to be on the safe side, but the maximum amperage charger should not exceed the specified rating of the batteries. It usually takes a significant amount of time to charge using a trickle charger.