# Boat Battery Winterizing Question **URL:** \ **Category:** Factual Questions\ **Created:** [September 16, 2013, 4:35pm UTC](https://boards.straightdope.com/t/boat-battery-winterizing-question/668984 "2013-09-16T16:35:44Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [September 16, 2013, 4:35pm UTC](https://boards.straightdope.com/t/boat-battery-winterizing-question/668984/1 "2013-09-16T16:35:44Z")
I purchased a 20 foot long pontoon boat with a 90 HP Mercury outboard over the summer and it’s now time to winterize it (I live in Montana). I know about running the gas out of the engine, but what should I do about the battery? Do I… 1. Leave it hooked up in the boat until Spring? 2. Disconnect it (remove the positive and negative batter cables) and leave it in the boat until Spring? 3. Disconnect it as above, remove the battery from the boat and put it on a trickle charger until Spring? 4. None of the above I’m storing the boat in my garage and the temperature may get down close to freezing if that makes any difference. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [September 16, 2013, 4:49pm UTC](https://boards.straightdope.com/t/boat-battery-winterizing-question/668984/2 "2013-09-16T16:49:47Z")
> [@dolphinboy](#): > > Disconnect it as above, remove the battery from the boat and put it on a trickle charger until Spring? No need to remove it from the boat. But keeping a lead-acid battery fully charged is likely to prolong its life. ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [September 16, 2013, 4:52pm UTC](https://boards.straightdope.com/t/boat-battery-winterizing-question/668984/3 "2013-09-16T16:52:23Z")
> [@Xema](#): > > No need to remove it from the boat. But keeping a lead-acid battery fully charged is likely to prolong its life. So it doesn’t hurt to have the battery on a trickle charge for 6 months? ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [September 16, 2013, 4:56pm UTC](https://boards.straightdope.com/t/boat-battery-winterizing-question/668984/4 "2013-09-16T16:56:07Z")
A “maintenance” charger is supposed to reduce the charge rate to a level that is safe to maintain indefinitely. It’s worth checking that the charger you plan to use will do this. ---
**Author:** ![control-z](https://avatars.discourse-cdn.com/v4/letter/c/eada6e/32.png) [@control-z](https://boards.straightdope.com/u/control-z)\ **Post date:** [September 16, 2013, 5:22pm UTC](https://boards.straightdope.com/t/boat-battery-winterizing-question/668984/5 "2013-09-16T17:22:45Z")
[A Battery Tender like this](http://www.amazon.com/Battery-Tender-800-Waterproof-Charger/dp/B000CITKCE/ref=sr_1_7?ie=UTF8&qid=1379352075&sr=8-7&keywords=battery+tender) is what I use for my motorcycle over the winter. The charger/maintainer is waterproof as a bonus, makes it more flexible should the need arise to park your boat outside. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [September 16, 2013, 6:44pm UTC](https://boards.straightdope.com/t/boat-battery-winterizing-question/668984/6 "2013-09-16T18:44:27Z")
Here are a some from HF for $10: [Float Charger 1](http://www.harborfreight.com/automatic-battery-float-charger-42292.html) [Float Charger 2](http://www.harborfreight.com/battery-float-charger-automatic-69594.html)[Float Charger 3](http://www.harborfreight.com/battery-float-charger-automatic-69955.html) ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [September 16, 2013, 7:09pm UTC](https://boards.straightdope.com/t/boat-battery-winterizing-question/668984/7 "2013-09-16T19:09:38Z")
> [@Crafter\_Man](#): > > Here are a some from HF for $10: > > [Float Charger 1](http://www.harborfreight.com/automatic-battery-float-charger-42292.html) > [Float Charger 2](http://www.harborfreight.com/battery-float-charger-automatic-69594.html)[Float Charger 3](http://www.harborfreight.com/battery-float-charger-automatic-69955.html) Ordered. Thanks.