Lead-acid batteries are commonly used to provide power to engage the starter motor and start your car's engine. Although the output voltage is only 12 volts, they are capable of producing high amperes which are needed to turn over your engine. Lead-acid batteries usually consist of six individual cells wired in series, each producing 2 volts. The cells contain sulfuric acid and two lead plates which, when energized, transfer electrons from one plate to the other. If the acid level dries out, the battery ceases to charge so you need to ensure you top the cells up.
Put on protective gloves before refilling your dry lead-acid battery cells. The cells contain sulfuric acid which burns clothing and skin, if it accidentally gets onto them.
Remove the six plastic caps on top of the lead-acid battery. If they are knurled caps, unscrew then using your fingers. If they are push-on caps, insert a suitably sized screwdriver under the lip of each cap and lever it up then remove using your fingers. If the caps have slotted tops, insert a screwdriver into the slot and turn the screwdriver counterclockwise.
Look in the six cells. You see two markers in each cell labeled "Min" and "Max." If your lead-acid battery is dry, the fluid level is below the "Min" marker.
Pour distilled water into each battery cells so it reaches the "Max" marker. You must use distilled water. Tap water contains impurities that can damage the lead plates.
Replace the six caps on the battery cells. Either push them into the holes or screw them into place using your fingers or the screwdriver. Don't over-tighten the screws or you can damage the plastic threads.
