Remove batteries for winter?

KHE

Member
Feb 28, 2012
238
West Michigan
Boat Info
1997 Sea Ray 240 Sundancer
Engines
Mercruiser 5.7L EFI alpha 1 Gen 2 drive
I usually remove my batteries for winter storage but I thought I'd ask this question: If the batteries are fully charged and the negative cables are disconnected, they shouldn't freeze. Is there any harm in just disconnecting the negative cables, making sure they're charged and then charge them in the spring? I don't have access to my boat when it is in the storage facility so I can't use a battery tender.

The reason I ask is the batteries are under the port side almost to the transom and it is a bear to contort myself down there and lift them out.
 
There was a recent thread about what to do with batteries over the Winter - search for that - lot's of opinions in there. But, yes, if the batteries are fully charged they will not freeze over the Winter.

Your model 240DA isn't actually all that bad to work on (in the bilge). Lot's of boats are a lot worse - Welcome to Boat Mechanics 101! If you can take them out and bring them home - keeping them on a smart charger over the Winter is the best thing you can do for them to help them last as long as possible. But it's not like removing the negative cable is a "bad" thing, either.
 
My 320 has a elec hatch and I just shut the power off and call it a day... Its hard to get to the battery and the elec hatch would be a pain also...
 
Thanks for the replies. In the interest of battery longevity, I'll probably pull them like I've done all the previous winterizations.

I am going to build a platform to drop into the bilge so I can stand on a flat surface when doing maintenance vs. the sloped part of the hull. I think that will make the task a lot easier.
 
Is the boat shrink wrapped? Is there a usable wall outlet? If you do not have or cannot use an on-board charger, Removing them may be best for you.

Over time, batteries will deplete. Depending on how fast they go down, how long the boat is laid up and how cold it gets, will determine how the batteries fare.
 
Is the boat shrink wrapped? Is there a usable wall outlet? If you do not have or cannot use an on-board charger, Removing them may be best for you.

Over time, batteries will deplete. Depending on how fast they go down, how long the boat is laid up and how cold it gets, will determine how the batteries fare.
The boat is stored at a storage facility - inside a pole barn. It is unheated, no access to an outlet and I do not have access to it while it is in storage. I plan on pulling the batteries and storing them inside for the 6 month off-season.
 
I have 5 AGMs. I remove all the positives. Better to remove the negatives? Does it matter?
 
I always pull mine and bring them inside. Charge once a month or so, and keep them off the floor of my garage. I know it's old school. but it's been workin all these years.....so.....
 
^^^ I did that too until I got a boat with 5.:(
 
I have 5 AGMs. I remove all the positives. Better to remove the negatives? Does it matter?
For the purpose of this thread, it does not matter.

But the reason to remove the negative leads is about safety. This is sometimes less of an issue with a boat than it is in a car because of the proximity of the battery to other metal items. A car battery is right next to lots of metal - the body, brackets, even the engine. In many boats, the battery(ies) are further away - and of course, the body of the boat is fiberglass. If you remove the positive first, and the wrench happens to also touch something that is still grounded (connected to the negative battery terminal), you will get a massive spark - big enough that it can create a crater in the wrench or even instantly weld the wrench to the metal part it touches. On the other hand, if you remove the negative lead first and happen to contact something metal (that's grounded), nothing will happen.

General rule is "take negative lead off first, put it back on last".
 
I keep mine from having direct contact with a concrete floor, as well... Even though I know full well that the "reason" for this dates back many, many years to when battery cases where made of more porous materials.
 
Dennis, that is practice when I connect my Jabsco oil extractor to the battery terminals. Positive first, then negative. Spark in bilge of gas boat not good!
 
For the purpose of this thread, it does not matter.

But the reason to remove the negative leads is about safety. This is sometimes less of an issue with a boat than it is in a car because of the proximity of the battery to other metal items. A car battery is right next to lots of metal - the body, brackets, even the engine. In many boats, the battery(ies) are further away - and of course, the body of the boat is fiberglass. If you remove the positive first, and the wrench happens to also touch something that is still grounded (connected to the negative battery terminal), you will get a massive spark - big enough that it can create a crater in the wrench or even instantly weld the wrench to the metal part it touches. On the other hand, if you remove the negative lead first and happen to contact something metal (that's grounded), nothing will happen.

General rule is "take negative lead off first, put it back on last".
Should also not be wearing any rings when accidentally grounding a wrench in contract with said ring. The third degree burn can be seriously damaging to you ring finger.
 
I removed my batteries for the winter. One thing I did was to cut a piece of plywood to fit in the bilge so I had a flat surface to stand/kneel on. The difference was huge and I wish I would have done that a few years ago. It made it much easier to remove the batteries since my feet weren't at weird angles.
 

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