How to Clean a Car Battery
If you have an old battery or a mechanical failing, that is probably going to require intervention from an automotive specialist. But if you've gone through the steps from What If My Car Won't Hold a Charge? and the problem is simply that the terminals on your battery need to be cleaned, that’s something you can do yourself.
Here’s what you need to do to make sure your battery terminals are spotless:
First and foremost, turn off your engine. While cleaning the terminals is a fairly straightforward DIY project, there is still a slight risk of injury. You can avert this risk simply by making sure you have the engine turned off while you work.
Next, loosen the nut holding your negative cable in place; you’ll likely need a wrench for this. Detach the cable from the post. Then, follow the same steps with the positive cable.
Take just a moment to visually inspect your car battery. Specifically, look for any fissures or cracks. If you see any, that means there is a problem with your car battery that you probably won’t be able to fix on your own; more likely than not, you’re looking at the need for a battery replacement.
You’ll also want to look at the cables and clamps themselves. Again, what you’re looking for is very obvious evidence of wear and tear. If your cables or clamps have big rips or tears, you’ll probably need to have them replaced. These things really cannot be mended.
Assuming you don’t see any of these obvious signs of wear and tear, you’ll want to mix your cleaning solution—one tablespoon of baking soda into one cup of water. Mix ‘em up thoroughly, then dip an old toothbrush into the mixture.
Use the toothbrush to scrub away any signs of corrosion you see on your battery terminals. Don’t be afraid to really scour thoroughly to get things squeaky clean. You may have to soak your toothbrush in the baking soda mixture a couple of times as you keep scrubbing away.
When you finish, use a spray bottle with cool water to rinse off any residue. It is imperative to make sure all baking soda and corrosion are washed away. Then, use an old rag or towel to pat the battery and clamps completely dry.
Use a little bit of petroleum jelly to lubricate the terminals.
Reattach the cables to their correct terminals.
That is the basic guide to cleaning your battery terminals—but here’s an alternate approach: If you’re on the go and don’t have access to the above supplies, see if you can find a Coca-Cola or a Pepsi somewhere, and pour it over the terminals. Let it sit for two or three minutes, then rinse your battery clean with cool water.
Note: You’ll want to follow the same basic safety steps we outlined above, including turning off your engine and detaching the cables.
If you can’t start your car, read our step-by-step guide with pictures on, How to Jump your Vehicle: A Step by Step Guide, it may be helpful! For more preventative maintenance, check out How to Prevent your Vehicle Battery from Dying.