Getting your boat battery ready for spring
Maintenance for your over wintered boat battery
Your boat battery is easy to forget in the excitement of getting water toys out of boat storage and into the water. A few simple boat battery maintenance tips will ensure that your battery doesn’t die while you’re out on the water for your first family trip!
Cleaning a boat battery
Terminal posts corrode over time. Using a small wire brush, brush off all rust, dirt, and corrosion. If the corrosion is stubborn, use spray cleaner and some WD40 to remove it. Be sure to place cardboard beneath your battery when you’re cleaning. This will capture any corrosion or chemicals you use. Any chemicals or battery acid that lands on the ground is potentially toxic to animals and children. Wipe down the battery housing, removing dirt, oil, and moisture, as these can effect battery life.
Filling a boat battery
If you’re using lead-acid batteries, you’ll want to check the elecrolyte level. The plates inside the battery need to be completely covered with liquid to ensure your battery will last! Usually, after storage or lots of use, electrolye levels will drop. Top off each cell with distilled water. Replace cell covers tightly and wipe up any spills. Remember to wash your hands incase any battery acid may have spilled over.
Charging a boat battery
After any amount of storage, it’s good to charge a battery overnight with a 3-stage charger. You want the battery to come up to and hold a charge of 12.4 volts. The best way to test this is with a simple voltmeter. Check the battery after you charge it overnight. And again after 24-hours. It should hold that 12.4 volts. If it does not, you may need a new battery! It’s also good to check the battery voltage again after taking your boat out for the first time to make sure the voltage is still holding. Marine batteries usually last 4-5 years if maintaned well.
Installing the boat battery
Using straps or bands, secure the battery in the boat so that it cannot move. Attach the leads to the posts, positioning positive and negative leads respectively. With a socket wrench tighten the terminal post nuts (use nylon insert locknuts). Coating the posts with dielectric grease or petroleum jelly will prevent them from corroding while out in the marine environment. Replace plastic post covers.
Test the battery under a load
Before setting out on the water, use your voltmeter (a highly recommended tool for anyone who has motors with batteries), to test your batter under a load. This means, with the boat in the water, engine running. Turn on the engintion. The battery should read no less than 9.6volts when the engine turns over. It should then return to its resting charge of atleast 12.4volts. You may need an extra hand depending on where your battery is.
That’s it! You’re ready for a fun day on your boat! By the way, battery failures are one of THE most common reasons people get stuck out on the water!
For tips on other spring time boat preparations see Boat U.S. Magazine