How to Restore a Dead 12V Battery
A car battery is meant to last a minimum of five years, but can last longer with the proper care. Car batteries have remained unchanged for the better part of fifty years. If your battery is dead and you want to restore it, it can be done without the help of a professional.
- Open the car hood and remove the battery by removing the battery cables. Make sure to remove the positive cable first using a wrench. Then remove the battery from the car placing it in a hard surface in a place with plenty of light.
- Clean the battery posts, by putting a battery post cleaner on a battery post and start turning it back and fourth until the post become clean from all dirt and grease. Repeat the process on the other post. You can all so use a wire brush to clean your battery posts.
- Check the voltage. Place the positive probe from a voltmeter on to the positive battery terminal and the negative probe on to the negative battery terminal. If the meter reads 12V that is a good sign, but anything under 12V means that something is wrong with one or more of the cells of the battery.
- Remove the cell covers place a screwdriver in to the slot on top of the cap turning it counter clockwise. Remove the cap and be careful not to spill any of the battery liquid especially on to your skin because it will burn right through your skin.
- Test the cells. Place the positive probe from the volt meter on to the positive battery terminal and the negative probe in to one cell at a time checking to see if the cell reads two or more volts do this to each cell until you find which cell is reading less then two volts.
- Use a funnel to add distill water to any low cells, the fluid should be at least 1/8 over the cell plates. Charge the batter for at least 24 hours using a battery charger.
- Return the battery back to the vehicle making sure to hook up each terminal to the right battery cable.