Blog - Ultimate Guide To Clean And Remove Car Battery Corrosion

Ultimate Guide To Clean And Remove Car Battery Corrosion Apr 17, 2016

Step-by-step guide on how to clean battery corrosion.

Author : Maddy Phillips Team NOCO Leader

Battery Corrosion?

Corroded battery terminals can cause your car or vehicle to not start. Battery corrosion can also lead to a myriad of other car battery problems, including damage to the vehicle chassis, electrical wiring, air conditioner lines and more. Proper battery corrosion prevention is critical to the health of the car battery and vehicle.

What Is Car Battery Corrosion?

Battery terminal corrosion is easy to identify. It’s the white, green or bluish stuff on your vehicles battery posts, battery terminals or battery cables. The white substance which you see around battery terminals is either lead sulfate or anhydrous copper sulfate. Anhydrous copper sulfate changes to blue color when exposed to moisture. The bluish material which you see around corroded battery terminals is hydrated copper sulfate and typically experience with copper connectors.Battery corrosion is a poor conductor of electricity, as it increases resistance within the circuit. As a result, the increased resistance can lead to transient current flow, which typically leads to your car not starting.

What Causes Car Battery Corrosion?

Battery corrosion is caused by hydrogen gas being released from the sulfuric acid inside the battery. As the gasses react to the ambient atmosphere, it begins to produce a corrosive environment. Other elements such as moisture and salts only accelerate the process. Typically, battery terminal corrosion occurs on the negative battery terminal, which is a symptom of undercharging the vehicles battery. The main culprit in undercharged batteries is that fact the alternator is not giving sufficient time to replenish lost battery capacity due the electrical load demand of the vehicle, and relatively short uses of the vehicle. If battery corrosion is present on the positive battery terminal, this is a symptom of overcharging.

How To Clean Battery Corrosion.

Preventing, not cleaning, battery corrosion should be the goal for proper battery maintenance. However, should you encounter a battery with corroded battery terminals, here is a simple eight-step process. It is always a good idea to use eye protection and use mechanic gloves while working around lead-acid batteries.
Battery Cable being removed from battery.

Step 1: Remove Battery Cables

Begin by removing the battery cables from the battery. Always start with the negative battery cable first, which is typically marked by the negative sign (-), its abbreviation (NEG), and/or black in color. Next remove the positive battery cable, which is typically marked by the positive sign (+), its abbreviation (POS), and/or red in color.

 A Corroded Battery Cable zoomed in.

Step 2: Inspect Battery Cables

Inspect the battery cables for excess wear or battery corrosion. Look for dried, cracked, and peeling insulation. Insulation is the plastic or rubber cover on the cable. The copper stranding limits current flow and becomes brittle when exposed to the elements. Frayed battery cables is a common reason for a vehicle not starting. Replace the battery cable(s) if any damage is present.

A battery cleaning agent being sprayed on corroded battery and removing battery acid.

Step 3: Remove And Neutralize Battery Corrosion

Spray a battery cleaning agent wherever battery corrosion is present on the battery or battery cables. Using a commercial-grade battery cleaner is important because it not only removes the battery corrosion but also neutralizes the battery acid. Many home remedies exist, but most do not clean, remove, and neutralize toxic battery acid, as well as, cause additional engine damage. In particular, never use coca-cola to remove battery corrosion. The synthetic sugars and phosphoric acid in coca-cola can cause further damage to your engine and surrounding components. Reapply if necessary. If you are unsure if the battery, and its connections are free from battery corrosion, you can use a battery cleaner with an acid notification agent.

Microfiber cleaning cloth and a battery terminal brush.

Step 4: Dry And Polish Battery Posts And Battery Terminals

Dry the battery, battery posts and battery terminals on the battery cable once the battery corrosion is removed. A microfiber cleaning cloth is a great option. Remove additional residue with a battery terminal brush.

Battery Terminal Corrosion Protectors being placed on battery terminals.

Step 5: Install Battery Terminal Protectors

Use battery terminal protectors (also known anti-corrosion pads) on each battery post, preferably one that is saturated in a battery corrosion preventative compound.

Connect clean battery cables to battery terminal.

Step 6: Reconnect Battery Cables

Reconnect the battery cables but in reverse order from Step 1. In other words, reconnect the positive battery cable first, and the negative battery cable last.

NCP2 being sprayed on battery terminal.

Step 7: Apply Battery Corrosion Preventative

Use a battery corrosion preventative spray or brush-on compound, and provide a generous coating on the battery posts on the battery and battery terminals of the battery cable.