How To Clean Car Battery Terminal Connectors

How To Clean Car Battery Terminal Connectors? If your car does not work as fine as it did yesterday, do not hasten to blame the battery. Sometimes the terminals can be faulty, preventing proper link-ups, which in turn could have led to your problem. How do you clean these terminals safely and adequately?

  • Your primary problem will be corrosion. This can and will happen, and they keep your battery from acquiring a proper connection.
  • Get yourself a 10mm wrench and a pipe brush.
  • Open the hood of the car, and shift the terminal caps on the battery to one side so you can work more freely. The car, needless to say, has to be turned off during this time. A quick clean-and-go is not your aim. This is an important and often risky process.
  • Take the negative cable (black) out first then the positive (red) one. Otherwise the red cable sends current through the metal (in this case your wrench) and shorts itself through the rest of the car and to the black cable, which serves as the ground. Taking the black ground cable afterwards leaves the car with no connection to the battery. This will sooner or later cause start-up problems.
  • Loosen the bolt on the negative cable. Extricate the black cable. Repeat the step with the red cable and its bolt. Place both cables away from each other. They should neither cross nor touch. Time to clean…
  • If you see varying amounts of powdery stuff around the nodes, this is corrosion. Wear safety gloves and goggles lest they fly into your eye with the breeze or get on your hand where they can cause red splotches or worse. This corrosion is sometimes highly acidic.
  • Get the pipe brush out, an unconventional but useful choice of tool. Brush thoroughly around both terminal contact nodes. This helps you get most of the corrosion off. Take hold of the bolt and cable wire for black and then red, use the pipe brush to clean the inside loops. Polish the contacts some more; compressed air devices also come in handy. Time to reconnect…
  • Remember, you connect starting with the positive (red) cable and only then the negative (black) cable. This is the reverse process from what you did earlier, and is imperative to the health of your battery.
  • Grease the nodes if you like. It helps keep them functional. Tighten the bolts back, leaving no slack whatsoever. Cinch any remaining fixtures on your car battery.
  • Sometimes, when connecting the black cable you will see a spark at the node. It is better to have someone in the car seat with a foot on the brake pedal just in case the spark is big enough to crank the engine and cause the car to lurch forward.


With all connections in place and the terminals clean and relatively shiny, you are good to test the battery. Turn on the ignition and see if the car starts properly. Leave the car on, wait 15 minutes so the internal computer or ECM comes to terms with the new state of things. You can now drive off into the sunset.