Automotive batteries typically don’t get much attention until you experience a problem starting your vehicle, however, despite their relatively long lifespans, it’s still important to keep an eye on your vehicle’s battery to ensure it’s free from corrosion or wear that can disrupt the electrical connection.
If you’ve looked at the engine bay of an old vehicle, you may have noticed a greenish-blue residue building up on the battery posts. This is the result of a problem in the battery allowing sulfuric acid to exit the battery and corrode the terminals, leading to the accumulation of this crystalized residue on your battery. In this article, we’ll go over why this corrosion occurs, what it could mean for your vehicle, and how to clean this contamination from your own vehicle’s battery.
Why Is Corrosion a Problem?
While battery corrosion buildup can occur over time without causing much of an issue, it’s possible for the corrosion to get to a point where it disrupts the connection between the battery cable and the terminals. Without a proper connection to the battery, it’s likely that the vehicle will struggle starting up or simply not start at all.
Where Does This Corrosion Come From?
The buildup you see on your battery is corrosion from sulfuric acid that has made its way out of the casing. This can occur for a number of reasons, but some of the most frequently seen include:
Overcharging
When the alternator is experiencing an issue that causes it to produce an excess of charge, it can lead to boiling acid which causes pressure buildup inside the battery casing, forcing battery acid to leak from around the battery terminals.
Oftentimes, an overcharging alternator will result in buildup on the positive battery terminal particularly.
Battery Casing Damage
Another common source of battery corrosion is damage to the battery casing itself. When the exterior of the battery casing is cracked, warped, or otherwise damaged, it will allow battery acid to leak from the casing and accumulate near the terminals of your battery.
If you notice visible damage to the exterior of your vehicle’s battery, it’s best to have it replaced as soon as possible to avoid corrosion and other potential issues down the line.
Battery Age
It’s also possible that battery acid is leaking not because of external damage or an alternator issue, but rather simply the wear and tear that automotive batteries experience over time. As the seals and casing of a battery degrade gradually, it may eventually allow sulfuric acid to escape from the battery and form corrosion buildup.
Battery wear may also be increased by environmental factors, as particularly hot weather can cause the battery to expand with pressure and potentially damage the casing around it.
How To Clean Battery Corrosion
Luckily, cleaning this corrosion buildup off of your battery posts is a relatively simple process and can instantly restore a proper connection between your cables and battery posts.
Step #1: Gear Up
Sulfuric acid is not something you want to be touching, ingesting, or breathing in in any way. After all, you’ve seen what it can do to the metal of a battery terminal. This is why it’s important to ensure you have the proper protective items for this, including long-sleeved clothing to avoid skin contact, some form of eye covering, and a pair of gloves.
In terms of tools, all you’ll need for this is a socket to detach the battery cables as well as some type of brush to clean the posts. A wire brush is best for this but an old toothbrush or similar item may also work.
Finally, you’ll need some form of cleaning solution for this. We recommend a mixture of baking soda and water, as the sodium-bicarbonate of the baking soda will neutralize the residue’s acidity while the bubbles produced by mixing it with water will help loosen up stuck-on corrosion.
Step #2: Remove The Cables
Start by removing the battery’s cables to gain better access to the terminal. Always begin with the negative (black) cable first, then move onto the positive (red) cable.
Step #3: Apply Solution & Scrub
Take a decent amount of your cleaning solution and apply it to the terminals of the battery. Use your brush to begin scrubbing away the corrosion from the battery posts. This may take a little elbow grease, but eventually, you should be able to remove nearly all of the residue.
Follow up with a wet rag to clean off the last of the residue and cleaning solution, leaving you with battery terminals that look brand new. Ensure the area is perfectly dry before moving on to the next step.
Optionally, adding dielectric grease or even some household petroleum jelly can help form a protective barrier that protects against corrosion in the future.
Step #4: Reattach Cables
Now do the reverse of step #2 by reattaching the battery cables, starting with the positive one first this time and then the negative cable afterwards.
Battery & Electric System Services in Rohnert Park, CA
If you’re experiencing corrosion buildup on your battery, or any other electrical system-related issues, don’t hesitate to reach out to the experts at RPM Automotive Services in Rohnert Park! Our team has extensive experience in providing electrical system diagnostics, maintenance, and repair on a wide range of makes and models.
Don’t let electrical issues linger and cause further damage to your vehicle, give us a call or schedule online to secure your appointment with the premier electrical system service and repair facility in the Rohnert Park area!