Best Practice for Batteries for Winter

[ebsail]

I have 2 Interstate group 27 wet cell batteries. I also have a 50 watt solar panel and a small on/off controller. Turns on at 13 volts and off at 13.8 Panel bought on ebay for $50 and controller was $16 new. I leave the batteries in the boat all winter, master on in the "both" position, with all circuit breakers in off position. This way, both batteries are in paralel and get juice from the single solar panel all winter and no checking is required. Soar panel should face south. Have used this for the last 6 years and I'm in the New York City area. I use the same system during the season. When I'm done sailing for the day, I just drop the solar panel on the cockpit seat. Never had to use any other charging in the last 6 years. Batteries are always at 13+ volts when I arrive to go sailing. Simple and it works.

[Cotemar]

Batteries can stay on your boat all winter if you can keep them fully charged, all will be good.

They will freeze and be damaged if they are not fully charged over the cold winter months.

Charge them once a month or connect them to a 5 watt solar panel.

I recommend the 5 watt solar panel as its cheap, easy and carefree for the whole winter without ever thinking about it.

You can buy a really nice 5 watt solar panel on e-bay for under $25 usd

[deblen]

Hi from N.B.,Canada.
I have been leaving my 2 wet cell deep discharge house bats. & 1 wet cell start bat. aboard for a number of yrs. with no ill effects that I'm aware of.
I make sure they are fully charged in the fall (late Oct),disconnect the neg. terminal cables,& there they sit til Apr.
Think about all the wheeled vehicles that are stored for the winter.
A charged battery will not freeze in winter temps. common to our latitudes.
My boat is land stored ,so no bilge pump worries.
It has a garboard drain plug,in case of accidental rain/snow incursion.

Just my experience. / Len

[Crew of Turning]

Mainesail has published the results of his own experiment with a 6 year old wet cell battery. It is worth a read, like all of his studies, quite scientific. Overwintering fully charged healthy batteries has little effect. The discharge is minimal. FWIW, we disconnect all our grounds for the winter on 4 GC2 units plus the start battery. Spring comes and all are tied together again and the solar panel is booted up. Good to go.

[Elie]

I've always kept my (6) batteries on board during our harsh upstate New York close to the Canadian border. I used to charge them from time to time in winter. Now, for the last few years, I use a solar pannel (275 watts) connected to my batteries. Never had any problem and my batteries are 7 years old and in good shape. Long time ago, when I was younger and full of energy, I used to store them, unstep the mast, inject massive dose of antifreez in my water tanks, along with other things, like removing my electronics, cushions, etc... Now I became lazy or more practical: Everything stays on board, and even my mainsail is left into my inmast furler. Well rolled, out of the elements in fresh air, in the cold. It is in my opinion better than folded in a bag. For my (5) water tanks, I empty them(960 litres!) and simply blow compress air into the ditribution tubings. In spring, there is no terrible taste of antifreez to deal with. For the engine, I feed the raw water system with cheap antifreez, start the engine to push away any water from the heat exchanger then emply the muffler of ist remnant antifreez. It works for me...

[ramblinrod]

Originally Posted by CourageousME

It's my first winter with my boat and recently lost my job. Finances are tight so I'm trying to learn what I can do myself.

I've got 4 sealed batteries (interstate brand I think) under my chart table bench. They somehow charge a 5th starting battery and a 6th windlass battery.

What's best practice for them? I'm reading some people simply disconnect them, others leave them as is- others use a tender (not something I can do).

In in Maine and it's cold. She just got pulled yesterday and will sit until May 1.

Thanks


Sent from someplace

We lay up several boats every winter.

The first thing I do is top up the batteries, and then throw the charger on. Go through the boat and freeze protect the systems. (In Ontario,
freeze protection includes pulling electric bilge pumps
out of the bilge so they won't get damaged if water if the bilge freezes.

When complete, I verify the batteries are fully charged, and then perform a load test on them.

If they pass then I disconnect the negative terminals to ensure there is no load
on them.

If they fail, I take them to the recycler, to be replaced in the spring.

In cold climates the self discharge over the winter is minimal. If charged, the batteries won't freeze.

For our own boat, we are on it frequently over the winter to perform repairs and improvements, and for our annual New Year's Day celebration, so we just
leave the solar charging system running.

PS, cover the boat. It keeps the water out, so your chemical dehumidifers can keep the inside dry and mold free. Drains, limber holes, and bilge
pumps don't work when water freezes. Freezing water can do a lot of damage to decks and hatches.

[billdre]

Originally Posted by Crew of Turning

Mainesail has published the results of his own experiment with a 6 year old wet cell battery. It is worth a read, like all of his studies, quite scientific. Overwintering fully charged healthy batteries has little effect. The discharge is minimal. FWIW, we disconnect all our grounds for the winter on 4 GC2 units plus the start battery. Spring comes and all are tied together again and the solar panel is booted up. Good to go.

+1 I have 2 AGM house batteries, 1 separate starter. Charge them full at pull out. Disconnect cables. Return in Spring. This is Massachusetts. Sub-zero at lot, but the cold weather slows the chemistry. It works fine.

[SteveInMD]

If you want to maximize the longevity of the batteries the best practice is to use a charger, solar or otherwise. That doesn't mean you will destroy the batteries in a few winters by not using a charger 100% of the time, however the chemistry is the same - anything but full charge allows some room for sulfonation even in cold weather. Perhaps the additional effort is not worth the year, or months? of extended life. However, if you have a solar system on the boat already, there is no reason not to use it over the winter.

[pcmm]

I bring mine home but leave the starter battery connected to power the bilge pump should it be necessary (I'd rather replace the starter battery than my house bank if the winter did damage it). The marina I'm at does not allow people to leave their boats connected to power for the winter while on the hard and walks around and unplugs boats that do connect. Has something to do with fire and liability.

[ramblinrod]

Originally Posted by pcmm

I bring mine home but leave the starter battery connected to power the bilge pump should it be necessary (I'd rather replace the starter battery than my house bank if the winter did damage it). The marina I'm at does not allow people to leave their boats connected to power for the winter while on the hard and walks around and unplugs boats that do connect. Has something to do with fire and liability.

We recommend to our customers to NOT remove the batteries if they have passed a load test, are fully charged, and have the negative terminals disconnected because:

1. They may damage the boat:
a) broken battery terminals, boxes, etc.
b) dropping or banging the heavy battery on teak or trim or something.
c) spilling acid on upholstery, carpeting, etc.
d) starting an electrical fire (shorting batteries while disconnecting).

2. They may hurt themselves:
a) lifting heavy batteries (pulled muscles, hernia, etc.)
b) falling off a ladder trying to carry batteries up or down
c) spilling acid on skin or splashing in eyes.
d) burns due to passing high electrical current through jewellery, etc.

Then they expose their boat and themselves to all of this in reverse when they put the batteries back in, including the risk of incorrect wiring, and systems not working or electrical fire.

There is absolutely no good reason to remove batteries from a boat for winter layup, unless they fail a load test, in which case, they should be removed to ensure they don't discharge, freeze, split, and spill acid.

As has been stated, with zero load (in cold climates) the minor self discharge won't hurt them, but better yet, leave them 100% charged on solar charging system "float".