How to Store Your Boat Batteries During the Winter

Posted by Crown Battery on Nov 20, 2018 1:30:00 PM

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. One of the best things you can do for your battery is making sure it is properly stored during the coldest months of the year. Correct battery winter storage can be the difference come springtime! Follow this simple checklist to winterize your boat batteries – and be sure they’re ready for a great spring startup:

Winter battery storage checklist

Just like with any battery, you must perform regular maintenance. This including watering and removing corrosion. For maintenance tips and instructions, check out our  Safety First Guide

  1. 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.
  2. 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.)
  3. 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.
  4. Remove batteries, storing them in a cool, dry place where they won’t freeze. (On wood surfaces, in garages or storage facilities, is recommended.)
  5. 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.
  6. To make charging easier, store batteries where they’re easy to access.
  7. 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.

Tags: Marine Batteries, Battery Maintenance, Boat Batteries