Nobody wants to start the spring boating season with a dead battery. It’s time-consuming and expensive – and let’s face it, you’d rather spend that time on the water.
Follow this simple checklist to winterize your boat batteries – and be sure they’re ready for a great spring startup:
- Perform regular maintenance including watering and removing corrosion. For maintenance tips and instructions, check out our Safety First Guide.
- Charge the batteries one final time. Charging ensures they’ll completely recharge next season, and it greatly reduces the risk of a frozen battery over the winter season.
- Disconnect the negative cable and wait a few hours before checking specific gravity or voltage. With your hydrometer, check each cell; specific gravity should be 1.265 - 1.285. (Alternately, you can check batteries with a voltmeter – 12.6V is the reading for charged batteries.)
- Disconnect terminals to remove all electrical loads from your batteries. Electronics have parasitic (“vampire”) loads – small power draws – even if they’re “off.” This slow drain, combined with battery self-discharge, is enough to damage batteries in the off-season.
- Remove batteries, storing them in a cool, dry place where they won’t freeze. (On wood surfaces, in garages or storage facilities, is recommended.)
- Ideally, trickle charge batteries or charge them monthly. This prevents self-discharge and extends lifespan. Batteries with a full charge are also less prone to freezing.
- To make charging easier, store batteries where they’re easy to access.
- Confirm that your charger is designed for your battery type. Flooded and AGM batteries frequently demand different chargers and algorithms. (Note: Smart chargers can help ensure batteries don’t overcharge.)
Worried your battery is failing? Ask your battery service center, technician, or dealer about load-testing. Your battery manual may also offer strategies for load-testing and other battery inspection procedures.