I have a sailboat with a deep cycle lead acid battery and a lawn tractor with a lead acid battery. Both the boat and tractor are stored outside and there are no electrical outlets nearby. I live in the Northeast the lowest temps I see are 0° F. I have read that I could: A. Give them a full charge in the fall and do nothing until spring. B. Continuously charge and discharge them throughout the Winter. C Keep them on a trickle charger the whole winter. I'm looking to get the best life I can out of these batteries. Thanks

 

If you have no electrical outlets nearby then I don't see why you are considering options B and C?

 

If you have no electrical outlets nearby then I don't see why you are considering options B and C?

In all fairness, solar panels are an option.

 

I would go for option A.
Keeping them trickle charged with a solar panel is possible but you have to be careful not to overcharge them which would damage the battery. "Trickle charging" means "float charging" where the battery voltage is maintained at about 13.8V.
Option C would be to take them home and store them somewhere warmer and dry!

 

Lead-acid batteries can sulfate after a few months if not kept charged.
I would do as BobTPH noted, and get a solar panel designed to trickle-charge each battery (example).
They charge at a low rate, which is unlikely to overcharge them.
I used one of them to keep a van battery charged that I seldom drove, which worked well.

 

Do they need a discharge/charge cycle to help them last longer?

 

Do they need a discharge/charge cycle to help them last longer?

For just over winter, I would think not.

 

solar panels are an option.

Was thinking the same thing.

Option C would be to take them home and store them somewhere warmer and dry!

A second thought I had as well.

I have nothing to add to this thread beyond seconding the above suggestions.

 

I have a sailboat with a deep cycle lead acid battery and a lawn tractor with a lead acid battery. Both the boat and tractor are stored outside and there are no electrical outlets nearby. I live in the Northeast the lowest temps I see are 0° F. I have read that I could: A. Give them a full charge in the fall and do nothing until spring. B. Continuously charge and discharge them throughout the Winter. C Keep them on a trickle charger the whole winter. I'm looking to get the best life I can out of these batteries. Thanks

Take the battery out of the boat and put it inside. Then you can charge it as necessary if it gets load using a standard 12V automotive bench charger. Leave it in the cold and depending on how cold, you can break the battery. The normal way to keep a battery healthy in winter in a vehicle is to start the vehicle and run it for awhile (go do a small errand or something). Since you have a boat, that's a little different, so take the battery inside. Full-size batteries aren't cheap.

crutchow's remark about sulfating is (of course) correct. You don't want the plates sloughing sulfate, it will kill the battery over time (it shorts the bottom ends of the plates causing loss of capacity/amperage). You also must maintain the water level (and should always used distilled water).

 

Warmer is not better. A lead acid battery will operate down to -20°C, and when fully charged the electrolyte does not freeze until -55°C. The self discharge rate halves for every 10°C reduction in temperature.
Fully charge your battery and leave it.
Don't cycle it, unless it is a tubular plate battery it will only manage about 300 charge-discharge cycles. Every extra one you give it is one fewer that you will get from it when you need it.
Whatever you do, don't leave it discharged. It won't work in spring if you do.
https://batteryuniversity.com/article/bu-410-charging-at-high-and-low-temperatures

 

Warmer is not better. A lead acid battery will operate down to -20°C, and when fully charged the electrolyte does not freeze until -55°C. The self discharge rate halves for every 10°C reduction in temperature.
Fully charge your battery and leave it.
Don't cycle it, unless it is a tubular plate battery it will only manage about 300 charge-discharge cycles. Every extra one you give it is one fewer that you will get from it when you need it.
Whatever you do, don't leave it discharged. It won't work in spring if you do.
https://batteryuniversity.com/article/bu-410-charging-at-high-and-low-temperatures

Will try this next season.

 

If the batteries are well maintained - no impure tap water used (which increases self-discharge rate) and the cells are balanced with an equalization charge - then a basic float charger would be okay I think. Flooded lead acid battery self-discharge rates (Trojan) spec. is 5-15% per month. I think it's the lower number 5% in cold temps. AGM is 3%.

OP you have to be careful, I've seen many crappy float chargers out on the market.
Funny are the ones that somebody unplugs "no need to have power on those" and they parasite discharge the battery. Or their output voltage is way off, it boils dry or sulphates. The Harbor Freight specials are pretty cheap inside.
I've had commercial US-brand solar chargers with stupid logic and high parasite drain, here after snow on the panels or winter cloud for weeks on small batteries, I find dead batteries, full sun and it does nothing. They won't inititate charging from the solar panel alone. Grrr.

It's an old wive's tale- but storing batteries on a cold concrete floor is terrible for them. You get a thermal gradient where the top is warm, bottom is cold and electrolyte stratification happens.
If they are stored, do it on wood or something insulating and away from any space heater.

Jay Leno's Garage got a bunch of CTEK smart maintenance chargers, I'm not sure how they are doing for his 180+ cars.
Those and the NOCO, are super expensive I am not a fan of them because they use low cost capacitors that dry out. You have to keep an eye on them.

 

Keeping them trickle charged with a solar panel

Solar panel(s) with small "smart" batt maintainer between batt and panel makes sense.

 

For our travel Trailer, my solution is to disconnect the battery and bring battery and the battery case inside for the winter. Charge it up every month or so, overnight. Then it is ready to go in the spring. Simple and easy, and ready to go when the winter is done.
PLUS, a handy battery for a jump start if Iever need one on a cold morning.

 

For our travel Trailer, my solution is to disconnect the battery and bring battery and the battery case inside for the winter. Charge it up every month or so, overnight. Then it is ready to go in the spring. Simple and easy, and ready to go when the winter is done.
PLUS, a handy battery for a jump start if Iever need one on a cold morning.

MB2 I've been doing that for years. It's getting difficult to crawl into the bow and pull the battery out. I'll try Ian's method.

 

OK, in a boat that is evidently a much different operation. On the trailer the battery box is outside, forward of the propane tanks, easily accessed with no crawling at all.
I have actually had to work on the electrical portion of a larger boat where the battery was inside the electrical segment. Unfortunately the vapors from charging in place had damaged every bit of the electrical system in that enclosure, including every switch and all of the fuse holders, and quite a bit of the wiring. The repair project was both tedious and expensive.
So adequate separation and venting would be a valid consideration. OR at least, having the battery in a separate enclosure.

 

A flooded car battery loses about 4mA just sitting there. I think the charger's parasite drain is important and a spec to dig for. It is typically 6-15mA.
What happens is bird poop on a panel, wind breaking wires etc. can give you a dead solar system.
One remote site a bear scratched his back on a pole and knocked over the panels. So you get no charging and at least double the parasite drain and arrive on site to find a dead, damaged battery.

We used the Morningstar SunGuard chargers but it's an older design that will not inititate charging a dead battery, it's missing a diode to power the IC from either panel or battery, and a 6mA drain. Stopped using those after much pain.
Customers specified the ASC charger as they were very reliable, would charge a dead battery up. But these are again an older design, 10mA drain and a SHUNT charger so they do heat up.
Both models are hazloc certified and potted.

The low dollar chinese specials on eBay etc. I have no idea how they work but they have some cheap parts in them. I imagine they have buggy firmware as well. I guess you have to weigh the battery costs and see that a low dollar charger is false economy.

 

NONE of those problems apply if the battery is stored inside an above-freezing temperature structure. Certainly handling a wet cell battery is a lot easier in one of those battery cases like I have. And there is no effect of the battery charging vapor on the related electrical system.
So certainly there is a trade-off, like most engineering projects.

 

Personally, I’d go with your A Option. Disconnect it with full charge for over winter. Handling batteries can expose them to physical damage.

 

Disconnect it with full charge for over winter.

As noted, storing them without charging for that length of time will likely cause some battery sulfation.
They should be connected to a trickle-charger