Batteries

Rxjoe

New Member
Oct 12, 2016
35
Cincinnati, OH
Boat Info
2015 Sundancer 280
Engines
Mag 350 Bravo 3
I searched the forum and found some older information on batteries, I just wanted to get some current opinions. I purchased a 2015 280 that has only been used the last 5 months. I am storing the boat in Rhode Islad where I purchased it from and will not have access until the spring when it is shipped. I wil be shrink wrapped ad stored outdors. I was under the impression the batteries should be pulled and stored inside for the winter. The broker said the batteries are fully charged and they should be ok to leave in for the winter with no charger? Thoughts?
 
^^^ That

You can certainly leave them in. Many folks do. My procedure is to check all cells and top off if needed (did that yesterday), then just make sure they are fully charged when disconnecting them (do that next weekend :smt089). You'll be fine come spring. I've got 5 heavy-azz batteries that there is no way in he!! that I'm lifting in and out of the bilge each season. The PO of my boat did the same process I do and I replaced the original (2009 nodel year, built in Oct 08) batteries at the end of last season. So I got basically 7 full years out of the original wet cells. Not too bad.
 
If you disconnect the batteries, how do you close the power hatch and reopen it in the spring? I've heard that the battery pack into the cigarette lighter is a bad idea for the electronics.
 
On my 97 330, after I disconnect the batteries and make sure the neg terminal can't flop back to the post, I turn shore power back and and flip the switch for the AC Converter. This will power up my 12v stuff and I can close the hatch, and shut everything down.
 
I charge my batteries and leave them in all winter, never had a problem.
 
AGM batteries or flooded? When were the batteries last charged? Flooded batteries have a self discharge rate of around 5 - 10% per month. Add CO detectors and any other equipment that is still powered when the battery switch is off (radio memory). Once a flooded battery reaches 50% discharged the freezing point is about -16F. A dead battery will freeze at close to 32F.

if you have AGM batteries that were fully charged before storage, you should be fine, AGM batteries don't self discharge as much as flooded batteries.

A boat in my marina had a battery freeze last winter. Luckily it was in a battery box that contained the acid that leaked out.
 
They actualy just put brand new AGM batteries in it because the boat came unplugged and batteries drained completely .
 
I was born and raised in RI. i left a battery in my first boat fully charrged and fully disconnected. It was under a seat and the boat had a full cover, so no wind. No problems. If your batteries are in any way exposed to the elements (wind and such), wrap them in a moving blanket.
If you have any trepidations as to who is handling it, call Ron at Boat Buffs. He can hook you up.
 
My mechanic winterized and told me it was ok to leave batteries connected over the winter? Said he's had no problems... should I be worried?
 
I just turn my battery switch off and leave them in all winter. Haven't had any issues.
 
Depends on if you have a draw that is hard wired around the switch. Many boats do - stereo memory, marcathode system, co detector, .....
Battery will be dead and need replaced by spring if you do. Disconnect the batteries is the only way to prevent it under this circumstance.
 
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If your battery was fully charged it should hold it for starting in the spring, if not replace it
If your battery was fully charged it will not freeze but if you have a load to kill the battery it will freeze. Sulfuric acid is a wonderful cleaner
 

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