How to Replace an Electrolyte in a Car Battery

Although many car batteries look different, the vast majority of them operate in the same way. Car batteries use lead and an acid solution, also referred to as an electrolyte, to turn stored chemical energy in the solution into electrical energy used to start your car. Over time, some of the liquid may evaporate or become lost, which means there is no longer enough electrolyte to power the car. However, replacing the electrolyte in a car battery can be done at home in a few minutes.

Things You'll Need

  • Safety glasses
  • Gloves
  • Distilled water
  • Turn off the car's ignition if the car is running. Make sure that your car is off for the entirety of this procedure.

  • Open the hood of your car and locate the battery.

  • Open the filler caps on the battery. These caps are on top of the battery and, when opened, will expose the chemical solution inside of the car battery. Be careful not to come in physical contact with any of the solution.

  • Look inside the filler caps. The solution inside should be touching the bottom of the filler ports. If it is not, you will need to add water to the filler port(s).

  • Add distilled water (not tap water) to each of the filler ports that need more solution. Do this until every filler port has fluid touching the bottom of the port.

  • Snap the filler caps back on.

  • Start the car and drive it for 30 minutes to allow the car's battery to recharge.