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How to Clean Marine Battery Terminals (& Prevent Corrosion)?

to clean marine battery terminals

No one wants to hear that deathly “click” when starting up their boat. Especially, if you are in the middle of a body of water!

To clean marine battery terminals you will need a wire brush, baking soda, and water. This magic tool and the two-ingredient combination can get your boat battery up and running in no time. 

Let’s go into more detail on the steps you need to take to clean the corrosion from your marine battery the correct way. We will also give you some tips on how to protect your marine battery terminals as well.

How Do I Clean Corroded Battery Terminals on My Boat?

to clean corroded marine battery terminals

The first thing you should know is the acid in lead-acid batteries are highly corrosive. So, it is important to understand some of the personal protective equipment (PPE) you should have before you begin to clean corroded battery terminals. 

To clean corroded battery terminals, you will need:

Step 1 – Remove the battery cables from the terminals. Use the pliers to loosen the nut and bolt connectors. For safety reasons, disconnect the negative (black) terminal first, then the positive (red) terminal.

Step 2 – Brush off any loose corrosion using a wire brush. Once the bigger pieces are brushed off, you’re ready to move on to the next step.

Step 3 – Mix and add the baking soda and water to the terminals. You can do this in a couple of different ways: Either coat the terminals in baking soda then spritz water on them, or mix the baking soda and water into a paste beforehand then apply it to the terminals.

Another option if you don’t want to use the baking soda and water mixture is buying a commercially available battery terminal cleaner from a marine or automotive supply store. This is a more expensive option, but it still gets the job done.

Step 4 – Let the mixture sit and bubble to neutralize the corrosion on the battery terminals. You will want it to sit for two or three minutes to really eat away the corrosion.

Step 5 – Wipe the terminals clean with a paper towel. You can also use a cloth, however, it’s much easier to toss a paper towel away than it is to clean than a soaked battery acid cloth.

Step 6 – Repeat the process (steps 2 through 5) for the cables. It may be easier to create the baking soda and water paste on your gloved hand and then wipe it onto the cables. 

After you’ve wiped the mixture from the cables and terminals on your battery, you are ready for the next step.

Step 7 – Use the wire battery brush to clean the terminals and cables a little bit more, then wipe them off with a paper towel again to remove any extra and leftover residue. 

You can use a regular wire brush , but for a deeper and more thorough clean, you can buy a battery terminal wire brush  made specifically for battery terminal cleaning.

If you are using a battery terminal wire brush, you’ll want to scrape the terminal using the female post brush side. For the cables, use the male post brush side to clean them.

Step 8 – Apply dielectric lubricant, Vaseline or petroleum jelly, or spray-on corrosion inhibitor to the terminal and cables. Place the dielectric or jelly lubricant on your gloved hand and apply it liberally to the terminals and cables.

Step 9 – Reconnect the cables to the battery terminals. Attach the positive (red) terminal, then the negative (black) terminal. Use a wrench to make sure the connections are tight. 

For a visual representation of these steps, check out the following video from Digi-Key’s blog:

How to Remove Battery Contact Corrosion - Another Teaching Moment | Digi-Key Electronics

What can I use to clean battery terminals?

NOCO Remove+ E404 14 Oz Battery Terminal Cleaner Spray And Corrosion Cleaner

The most common battery terminal cleaning solution used is a mixture of baking soda and water or a battery terminal spray  that can be bought from automotive supply stores or marines. Baking soda and water neutralize the acid in lead batteries.

How do you remove green corrosion from battery terminals?

to remove green corrosion

The corrosion on top of battery terminals can be a white, blue-tinge, or green color. To remove green corrosion from battery terminals, you will use a mixture of baking soda and water.

The color of the corrosion will change depending on the type of metal on the terminal ends. Green or greenish-blue corrosion is typically formed because the connectors are made of copper metal. If the connectors are made of aluminum, they will be a whiter color.

Green or greenish-blue corrosion on the positive terminal means the battery may be overcharging. If the white corrosion is found on the negative terminal, it means the battery was not charged long enough.

A green corrosion build-up at the battery terminal connectors can also be a good indicator that it has been building up for a while. So make sure to check your battery terminals and cables on a frequent basis.

How to Protect Marine Battery Terminals?

CRC 05046 Battery Terminal Protector - 7.5 Wt Oz.

To help protect your marine battery terminals, you will want to coat the terminal connections with white lithium grease , Vaseline jelly , or another anti-corrosive lubricant made for battery terminals.

Some users complain about using grease and Vaseline, as it collects dirt. A wonderful alternative to this is a battery corrosion inhibitor spray . Find them at marines, automotive supply stores, or online.

Also, make sure your battery terminal connections are tight to prevent them from loosening over time. This helps prevent corrosion build-up and unwanted discharge.

You will want to check for corrosion at the battery terminal posts and cable ends once every four to six months.

What to put on marine battery terminals?

12 Pieces Battery Terminal Anti Corrosion Washers

Another neat trick that many boaters do to protect their marine batteries from corrosion is they place anti-corrosion pads  between the terminals and cables. They look like washers, only they are made of fiber instead of metal.

Most anti-corrosion battery terminal pads are colored red and green to help you separate the positive (red) from the negative (green or black) terminal. For a better deal, you can purchase anti-corrosion pads that come with female and male wire brushes .


You now know how to clean marine battery terminals and prevent corrosion on your marine battery. Our step-by-step guide will help you clean your battery thoroughly and extend the life of your battery.

Whether you are in your garage, at the docks, or in the middle of a lake, you will be prepared to take care of the corrosion on your battery.