DIY Car Maintenance: How to Clean Car Battery Terminals

By Blog


If you’ve ever gotten in your car, turned the key to start the ignition and nothing happened, chances are pretty good that it was a battery problem.  Maybe you left the lights on and it drained your battery, or maybe there was something more to it, like dirty, greasy, corroded battery terminals.

This problem pops up more often than you might think, especially if you leave your car sitting without running for extended periods of time.  You see, when the engine doesn’t run, and it just sits, the battery terminals oxidize at a rapid rate.  In order to combat this, you should start checking your battery terminals, regularly, for build-up and corrosion.  If this happens, your battery posts will appear to be covered in a white, ashy substance.  Fortunately, these are easy to clean and something that you can do entirely yourself.

What You’ll Need 

Before you jump under the hood, lay out all of your tools and cleaning supplies.  These include:

  • Locking pliers or vice grips
  • A battery post brush and battery clamp brush – you can get this combination tool at any auto parts store or order it online.
  • A wrench
  • A toothbrush
  • Baking soda
  • Water
  • A clean, lint-free cloth
  • Grease or petroleum jelly

How to Clean Your Car Battery Terminals

Step 1 – Once under the hood, remove the battery cables from the battery terminals.  To do this, loosen the nut on each cable clamp, then remove the cable clamp from the negative terminal first.  It will be marked with a minus (-) sign.  Always remove the negative clamp first!  (When you go to put them back on, then reverse the process and put the positive (+) clamp back on first.)  If you find that the cables are very corroded and won’t come off easily, use your locking pliers (vice grips).

Step 2 – Take a close look at your car battery cables and clamps.  You’re looking for any corrosion or excess wear.  If you see any damage, you’ll need to replace both the cables and clamps so that you don’t run into any future problems.

Step 3 – You’ll also want to take a close look at the terminals and battery case for any cracks or damage.  If you find any, replace the battery.

Step 4 – Secure your loose cables so that they can’t touch the terminals.

Step 5 – Pour your baking soda directly onto the posts.

Step 6 – With a wet toothbrush, scrub the baking soda into each terminal post and then the cable clamps.  We recommend wearing gloves and eye protection to avoid getting any debris on your skin.

Step 7 – If your toothbrush isn’t getting all of the muck off, use your battery terminal cleaner brush.  You can also use the clamp cleaner to shine up the insides of the cable clamps.  If you don’t have this on hand, you can just use a plain, steel wool pad.

Step 8 – Dry everything off with your lint-free cloth.

Step 9 – To slow corrosion, wipe grease or petroleum jelly on all exposed metal surfaces.  This includes the posts, clamps and battery cables.

Step 10 – Replace the clamps, starting with the positive (+) clamp, first.  Then secure the negative (-) clamp.  Tighten each into place using your wrench.

Step 11 – If you removed a rubber boot or plastic shield to get to the positive terminal before you started, re-secure it.  If you didn’t have one, you may want to buy one from your local auto parts store.

It’s that easy!  And best of all – these regular checks and maintenance will help make your battery last longer.

Featured photo credit: BruceEmmerling via Pixabay, cc