Batteries & WInter Storage

Ed Schenck · Oct 30, 2011

This was all discussed just recently. Regardless I think the answer might lie in knowing what kind of batteries you have.

Ed Schenck · Oct 30, 2011

Here you go, should get you started: http://forums.hunter.sailboatowners.com/showthread.php?p=854818&highlight=winter batteries .

Stu Jackson · Oct 30, 2011

Ed Schenck · Oct 30, 2011

Stu's probably right. Unless they are Gels or AGMs in which case come spring they will be shot.

Maine Sail · Oct 30, 2011

cb32863 said:
So a boat I am probably bringing home has 2 banks of one battery each. Wired for shore power as well. So I am wondering as it will be soon snowy and cold here, what would be the best way to store the batteries.

Leave them in the boat and connect up the shore power and keep them charged.

Bring them inside and keep them on a charger in the house.

Let them be and charge them in the spring before I put her in the water.

Thanks in advance.

D = None of the above

Charge to full in the fall then completely disconnect from the boats DC system and leave them where they are. Perhaps top up once over the winter. If your area is cold enough may not need to top up. Self discharge drastically slows in cold temps and a full battery will not freeze until -72F... You should not let any battery sit in storage without charging it to 100% first.

Maine Sail · Oct 30, 2011

cb32863 said:
OK, as I am getting a multitude of answers. I am in Minneapolis and as you know, it can get pretty cold here. Though the day it gets down to -72F, is the day before I move.... So just charge them up, make sure they are topped off with water, and charge them back up in the spring. Maybe in the middle of January or February do a recharge and be good with it.

yep you'll be fine. We've had 20-30 below in the years I've left batteries on-board and never once had an issue. Just be sure they are topped up.. Batteries like cold and will have a long life if stored in cooler temps. Even if I took them off the boat I'd still keep them in the un-heated shed rather than my heated garage or basement.. Course back surgery is more costly than it's worth to move the batts when you don't need to.

Benny17441 · Oct 30, 2011

How far are you from home? If is just two batteries take them home, charge them fully and let them sit in the garage. (reminds me of an old wives tale, "do not sit batteries on concrete as that will zap the charge out of them". May be there is some thruth to it if the slab is real cold.) Every three weeks plug the charger back on and recharge fully again.

Maine Sail · Oct 30, 2011

Benny17441 said:
How far are you from home? If is just two batteries take them home, charge them fully and let them sit in the garage. (reminds me of an old wives tale, "do not sit batteries on concrete as that will zap the charge out of them". May be there is some thruth to it if the slab is real cold.) Every three weeks plug the charger back on and recharge fully again.

Cold weather actually benefits and can extend the life of lead acid batteries. It dramatically slows self discharge and can also slow the sulfation process way down s they self discharge at a considerably slower rate. The batteries must be topped up to prevent freezing and if they are they can be good for a couple months in-between charges, if the winter temps stay cold.

Last winter I charged them to full in early November and did not put a charge on them again until early April. The batteries were still at a resting open circuit voltage of 12.68 volts and ths was confirmed with an SG test. Full on this bank is about 12.73V. If they had been in my basement I would have needed to top them up every three to four weeks due to the much higher temps.

I have a bunch of deep cycle marine batteries sitting around my shop. In the summer I need to flip the charger on about once every two to three weeks to keep the batts at full charge. In the winter I never flip it on as they just don't self discharge at anywhere near the rate they do in warmer temps.

Dalliance · Oct 30, 2011

I've been doing exactly what Maine Sail recommends here in Chicago and I've had no problems. With the batteries or my back.

Maine Sail · Oct 31, 2011

cb32863 said:
Never posted where the boat will be stored but, conveniently in my driveway.

Ours will be next to the house too, batteries still on-board and back happy......

Benny17441 · Oct 31, 2011

I agree, if on your driveway, leave them in the boat. Did not grasp that when you said "bringing home" you meant it literally. Thanks Maine for poiting out perhaps another of our climatic differences as here in Florida we do not notice any difference in the discharge rate from summer to winter. Wether they are going to be attended or not when laying the boat out is what makes the difference for us.

SailingHarry · Oct 31, 2011

Batteries on a concrete floor

Benny17441 said:
How far are you from home? If is just two batteries take them home, charge them fully and let them sit in the garage. (reminds me of an old wives tale, "do not sit batteries on concrete as that will zap the charge out of them". May be there is some thruth to it if the slab is real cold.) Every three weeks plug the charger back on and recharge fully again.

That isn't an old wives tale and is 100% correct -- it just doesn't apply to the batteries we use. If you happen to still have a set of batteries where the case is made of creosote impregnated wood, you'll want to keep them off the floor. If like most of us, your grandfather got rid of them before you were born, it's not an issue.

Harry

Maine Sail · Oct 31, 2011

SailingHarry said:
That isn't an old wives tale and is 100% correct -- it just doesn't apply to the batteries we use. If you happen to still have a set of batteries where the case is made of creosote impregnated wood, you'll want to keep them off the floor. If like most of us, your grandfather got rid of them before you were born, it's not an issue.

Harry

Yep that's exactly where that came from. Sadly when the industry moved to plastic cases our grandfathers still held onto their long held beliefs that the cement is what sucks the life out of the batts..

WilliamH · Oct 31, 2011

Battery Storage

Miane Sail's advice is right on. If the battery can not tollerate storage over the winter after a full charge, they need to replaced. I worked in a Marina where we took the batteries out and but them on a trickel charge over the winter. Using this method fooled us into thinking the batteries would hold a charge during the summer months. We found disconnecting the batteries, leaving them in the boat over the winter, and if the battery would not have enough life to to turn over the engine after being in storage, it was bad. I have used this method on my boat for several years with success. Also as Maine Sail states, taking the batteries out is tough on the back. I have five batteries on my boat, they are not light.

DougM · Oct 31, 2011

My boat is stored outdoors in Northern Michigan. The yard people told me not to worry about pulling out the batteries, they just disconnect them. Both batteries were routinely replaced at five years ( both still sort of OK , but not perfect). I never had a dead battery in the Spring. I could never get to the boat in the winter anyway as I am 1000 miles away. Besides its a pain to pull out the batteries anyway.