Maintaining the battery is very important especially if one finds themselves stuck because of a dead battery, for which some tools are used. Engine must always be off as well as all accessories to prevent a back-feed of electricity into the vehicle, and also remove the cable from the negative terminal. A sealed battery, which is fitted as standard, does not need electrolyte checks or water additions but if an aftermarket battery that needs topping up is fitted, check the electrolyte level in each cell and top up if necessary using distilled water. Examine whether there are signs of damage on the positive terminal and cable clamp and examine the external condition of the battery for crack, and while checking insulation damages ensure that the cable clamps are tightly installed. Corrosion, if formed, should be removed; cables should be cleaned and reinserted so that the contact is made with a clean surface. Reduce corrosion by using treated washers or by using petroleum jelly on the terminals. Make certain the battery carrier is not seriously rusted, and the hold-down clamp bolt is tight; remove rust from the battery carrier and nearby regions using a mixture of water and baking soda. Sacrificed metal parts should be overplayed with an anticorrosive and painted. For charging, if using cells remove the caps or cover the terminals, connect the charger leads in a right way, always making sure the charger is at 12 volts. Be careful with the battery and its charging, especially if the rate is high, and use a hydrometer to measure the specific gravity, if the battery has caps. Hydrometers are built-in in batteries with sealed tops to display the charge status; batteries devoid of this feature should be checked by digital voltmeter where full charged battery should read 12.6 volts and above.