How to Clean a Boat Battery

hand brushing the terminals of a car or boat battery clean
  • 1 hours
  • Beginner
  • 0-50
What You'll Need
Baking soda
Lint-free cloth or rag
Petroleum jelly
Terminal and connector cleaner

Cleaning a boat battery is one of the small but extremely important things that need to be done to properly maintain your boat. Boat batteries are usually made of a combination of lead and acid. These types of batteries do present a hazard to the boat owner especially if the battery case becomes broken. To clean your boat battery, follow the steps below. This maintenance plan should be completed at least twice a year (Sping and Fall).

Step 1 - Clean Up

Wash your hands thoroughly before you begin the process of cleaning your boat battery. You may wish to cover your hands with protective gloves (latex or a thick kitchen rubber glove works well). You may also wish to cover your eyes with a protective pair of eye goggles. This prevents alkaline or acid splashing in or around your eyes.

Step 2 - Visually Review the Battery

Review the battery’s exterior very carefully. Look for any cracks in the case, dirt in and around the terminals. Is there is leaking electrolyte or any further exterior damage, replace and recycle your battery right away.

Check the battery cables and the connections. Inspect for broken or damaged components. Clean the cables. Tighten all the connections.

Step 3 - Test the Battery

Test the voltage and the specific gravity of the boat battery. Both tests will indicate whether you should continue with the maintenance process of the boat battery. Using specific gravity tests describe the density of the fluids relative to that of the water contained in the boat battery. If the reading shows a number larger than one, the liquid in the boat battery is denser than the water.

Use a hydrometer to perform this test. A hydrometer can be purchased at any local home improvement store. Test each battery cell within the boat battery. At the same time, test the temperature. Correct any temperature readings as necessary and as directed in the manufacturer’s information. If the readings are below 1.277, fully charge the battery and retest it.

Step 4 - Clean the Boat Battery

After you have tested the battery and recharged it (as needed), complete the maintenance process by completing a thorough cleaning. First, check that each vent cap on the boat battery is securely fastened and maintained in the correct position. Second, clean the top of the battery with a damp cloth, rag or lint-free microfiber cloth.

Submerse the cloth in a mixture of baking soda and water. This will neutralize the acid. Scrub the battery as needed or until fully cleaned. Rinse the battery lightly with water and a fresh cloth. Then, clean the terminals. Use a terminal cleaning tool for best results. Add a thin coat of petroleum jelly on the terminal and connectors.