Making sure your vehicle starts reliably requires taking good care of the battery. You should have all required tools and equipment before you start any work. There are a few precautions to take when working with batteries such as switching off the engine and disconnecting the negative terminal. Avoid producing sparks or flames or charging the battery in an area with poor ventilation since batteries generate highly flammable, explosive gas which is hydrogen. As such, its electrolyte contains corrosive sulfuric acid; you should not let it come into contact with your eyes, skin, clothes, etc. You must also wear protection gear before any battery maintenance exercise. This can involve inspecting the battery for external damages like corroded connections, loose clamps or cable problems. If there is corrosion present on it, then it must be removed for cleaning. In order to clean them, use a solution made of baking soda and water with a brush that cleans battery ends as well as terminals while wearing goggles and gloves for safety reasons. The tray and hold-down clamp where the battery is located should not be damaged and should be tight enough to secure it while driving. It is better to remove the battery from the car during charging so that escape gas does not damage its paintwork; therefore it is preferable to charge elsewhere this way that will prevent paint damage by escaping gasses. One would restore power to a discharged cell or keep it from discharging further by using a slow-rate charge through 1-2 amp chargers only. Quick charging is meant for emergency purposes only though charges vary depending on gravity measurements since observing overheating here is important. Sealed ones can contain hydrometers built inside them while others can be checked using digital voltmeter.