Winterizing Batteries

I've looked through the threads for this one, so if it should be obvious please point it out.
My Mainship has two golf cart batteries as the House Bank to which nothing else is turned on, but the bilge pump is connected. Although they are fully charged they are not plugged in to AC while the boat is on the hard for the winter.
I leave for Florida for six months and she is left to fend for herself.
Although she is covered with a tarp this year, can I put a small solar trickle charger ( the type used on dashes in car lots ) to ensure the batteries are kept topped up?
What say you?

Disconnect them and leave them rest alone that’s it

L

A small solar charger could be good, but if anything happens to the feed from the solar panel the solar controller itself can run the batteries down over a period of months. If the batteries are fully charged and positively no devices connected, they will be fine. Many thousands of boats are stored in New England for 6-7 months every year the same way.

Ken

As your post implies, batteries are fine in the winter as long as they are kept charged up.


It is not clear to me how your boat is set up, but you do state that no charger is hooked to the pair of GC battteries used for the house (hurray for using GCs!).



So a small solar charger is ok, but I recommend that you get one of the 50 watt packages with a controller that we discussed on another current thread. That gives enough power to compensate for parasitic loads like a CO detector. The other way is to make sure that the GC batteries are fully charged and remove the negative lead to the batteries so that any unknown parasitic loads don't draw it down. It will be fine next spring if you do this.


David

If your boat is on the hard for the winter presumably it won't sink. Unless you have problems with rain leaking into the boat and filling the bilge, I'd just check the water level, charge the batteries, and disconnect them and let them sit. With no drain they will be fine over the winter. This gives you a chance to clean the contacts for the batteries, use some dialectric grease and reconnect them in the spring. They should be just fine.


Nothing wrong with using a small solar to keep them charged but since there is no need to have the batteries connected, I see that as an unnecessary complication.

Thanks for your advice. Last winter I did as advised; charging fully and taking off the negative lead.
It was the first winter I had the boat and it appears snow (or rain) may have gotten in through the tarp openings and with Toronto being always in a state of flux; cold snowy days followed by warm or rainy days, so in the spring there was 4 or five gallons of water in the bilge.
I don't have a garboard drain (as yet; with plans to install one) so to insure it doesn't happen again I wanted to keep the bilge pump operational during the winter. I plan to tighten up on the tarp cover as well. I should have mentioned that in my original post.
With this new knowledge would you still consider a small solar charge?
Some locals recommended loosening the packing gland to let small amounts of water to exit slowly. Is that an option?

If that 4-5 gallons freezes (and in Toronto it will) and the bilge pump is sitting in it, then the bilge pump will possibly be ruined. If the bilge pump is frozen and topsides water thaws and leaks in and triggers the bilge pump then that will ruin the bilge pump. So I would not leave the bilge pump powered with the boat on the hard- been there, done that.

If you can tighten the tarp up so no more than 4-5 gallons gets in this winter, just pour 3 gallons of antifreeze in the bilge with the bilge near dry. Then when water gets in, it won't freeze.

Loosening the packing gland might work if the 4-5 gallons of water gets up to the packing gland. On most boats it won't. Reread the first paragraph to see what could happen.

David

djmarchand said:

If that 4-5 gallons freezes (and in Toronto it will) and the bilge pump is sitting in it, then the bilge pump will possibly be ruined. If the bilge pump is frozen and topsides water thaws and leaks in and triggers the bilge pump then that will ruin the bilge pump. So I would not leave the bilge pump powered with the boat on the hard- been there, done that.

If you can tighten the tarp up so no more than 4-5 gallons gets in this winter, just pour 3 gallons of antifreeze in the bilge with the bilge near dry. Then when water gets in, it won't freeze.

Loosening the packing gland might work if the 4-5 gallons of water gets up to the packing gland. On most boats it won't. Reread the first paragraph to see what could happen.

David

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It will take less time to install a garboard drain than to hook up a solar panel especially after you realize you need to buy wire and connectors to extend the cord of that 40Watt, $40 unit from Canadian tire and it might not keep your batteries up. The low angle of the winter sun and cloudy days may (will likely) negate it's usefulness.

$20 for a garboard drain, a little caulking, 30 seconds to drill the hole, 2 minutes to put in three screws.
or .... $2.95US if you buy it here

boatpoker said:

It will take less time to install a garboard drain than to hook up a solar panel especially after you realize you need to buy wire and connectors to extend the cord of that 40Watt, $40 unit from Canadian tire and it might not keep your batteries up. The low angle of the winter sun and cloudy days may (will likely) negate it's usefulness.

$20 for a garboard drain, a little caulking, 30 seconds to drill the hole, 2 minutes to put in three screws.
or .... $2.95US if you buy it here

Click to expand...

And even if you do not plan to install a drain right now, it will take you less time to empty your bilge with a shop vac then to setup your trickle charger.

L

What is a garboard drain?

When we were in the tropics, a lot people who left there boats on the hard, installed drains. No maintainance.

Dave:

Larry M said:

When we were in the tropics, a lot people who left there boats on the hard, installed drains. No maintainance.

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Thanks Larry. I assume that is installed near the lowest point in the bildge and goes directly through the bottom. That would seem to be the simplest solutions. If it was me, I'd be lazy and just have the yard install one when the boat was hauled.

Back in the days of wooden boats, the garboard was the first plank next to the keel. So a garboard drain was a drain fitted into the garboard.

I think that I would vacuum the bilge dry before you leave and then put some non toxic antifreeze in the bilge in case some water gets in. Easy.

dhays said:

Thanks Larry. I assume that is installed near the lowest point in the bildge and goes directly through the bottom. That would seem to be the simplest solutions. If it was me, I'd be lazy and just have the yard install one when the boat was hauled.

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On trailer boats they’re generally installed through the transom.

John

Last time I was on the hard in Florida, either you had a drain or the marina drilled a hole in the bottom of your boat.

If you have a removable paddle wheel speed transducer just pull it out and stuff the hole with old fiberglass screen material to keep critters out.

The literature says lead acid batteries self discharge at a rate of about 5% per month. Some say as high as 10%. Trojan says 70% is their bottom line for discharge. I lost two batteries when the marina failed to plug in the charger on the house bank midway through an 8 month winter storage period (inside heated). (The contract said they would do so). I have them plug it in every two months for peace of mind. I also do an equalize cycle the day before it goes into the storage building. By the way, many cheap trickle chargers to not have circuitry to prevent them from sucking the life out of the battery if the AC happens to get disconnected for an extended period....

When I had GC battys I removed them for winter storage and kept them home on a maintainer. I did have a garbord drain but never had enough leakage in to be a problem.
Current Mainship has 3 - 8D's AGM's and I make sure they are charged and disconnect neg terminal... too much parasitic drain if they stay connected. Too much hastle to remove being 8D's. I won't replace them in kind when the time comes - likely will be AGM GC's for house ? start TBD?

I have checked V in spring for last 3 yrs and have always had 12.5 - 12.6V after 6 mos on the hard but that's w/ AGM's - FLA will likely lose roughly 2x what an AGM does.
A few gals of water in the bilge shouldn't be a problem but if you can install a drain all the better. I would remove the GC's and put them on a maintainer - they like being kept charged and it will help longevity of the battys IMO.

If the boat is parked anywhere near a building with plain ol' 110 wall sockets, I'd attach a light weight extension cord into the power inlet on the side of your boat (via a 30 amp to 110 adapter). Disconnect everything but the battery charger from your battery bank. Leave the charger switch "ON" on your AC panel. Coil a long extension cord and leave it on a hook or bungee attached to the boat. Have a friend or yard person plug it in for a day every couple of moths. That's how it's done inside our storage building (for the past 13 years). There's a small arc when plugging in. Guess you could put a switch on the cord if that's a concern to anyone. No big deal with a 50 amp charger. I leave an AC light on in the salon as a tell tail .

Depending on age a batt will self discharge between 1/2% and 3% per DAY


Solar is great or a once a month charge from house current.


The higher the voltage is kept long term , the less sulfation = longer life.

Rufus said:

The literature says lead acid batteries self discharge at a rate of about 5% per month. Some say as high as 10%. Trojan says 70% is their bottom line for discharge. I lost two batteries when the marina failed to plug in the charger on the house bank midway through an 8 month winter storage period (inside heated). (The contract said they would do so). I have them plug it in every two months for peace of mind. I also do an equalize cycle the day before it goes into the storage building. By the way, many cheap trickle chargers to not have circuitry to prevent them from sucking the life out of the battery if the AC happens to get disconnected for an extended period....

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Unattended charging is always a risk, in most cases higher than self discharge of disconnected batteries put to bed correctly. Over the years I have seen tens of thousands of dollars in ruined batteries cause by unattended charging.

A batteries self discharge rate is affected by temperature. If the batteries will routinely be at 75F or higher then periodic top ups (safest) a PV set to a low float of 13.2V or so, would be a decent choice. In either scenario the batteries should be disconnected from the vessel for long term storage. One of the biggest causes of destroyed battery banks is a faulty & stuck bilge switch.

As others have said take the time to install a garboard drain your boat will not only smell better when you return but your batteries won't be exposed to any risk of a faulty controller, stuck bilge switch, occluded PV due shading or the PV disappearing due to five finger shopping....

In colder climates the self discharge rate is a relative non-issue but, in Florida it should certainly be a consideration based on average battery temp.


Winter Battery Storage & Self Discharge Characteristics




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CMS said:

Unattended charging is always a risk, in most cases higher than self discharge of disconnected batteries put to bed correctly. Over the years I have seen tens of thousands of dollars in ruined batteries cause by unattended charging.

.

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If the charging system is reliable and relatively sophisticated, and the batteries are in good condition and properly prepared, the risk is very low. Solar panels are unattended. As I said, dozens of boats are plugged in monthly, or bi-monthly by service staff at our storage building. They do the winter disconnect/configuration, or inspect the owners work....they/I service the batteries if required...they/I do a risk assessment. They do not climb aboard each boat and watch it charge. They plug them in and head back to the shop area. At the end of the day they walk through the building and pull the plugs. I caution them not to plug in too often as the water level drops over time. The only batteries I've ever lost is when they failed to perform the routine. Now, if the batteries are old and showed signs of age, I wouldn't follow this routine. Same for an unsophisticated charger. Up front risk assessment.

For the past 6 years I have left the 4 GC batteries in our boat over the winter with the battery switches turned off. They are in a horrible position to remove. In the fall they are generally at about 6.5 volts and in the spring 5.8 to 6 volts. Never seemed to do any harm. I do leave the battery breaker turned on and a cord at the transom so early spring I do hook up the generator and charge them as soon as I can get access. Disconnecting is likely a better solution but not always necessary if there is absolutely no load. I do use a shop vac and get all the water out of any bilge areas.

Winterizing batteries

boatpoker said:

It will take less time to install a garboard drain than to hook up a solar panel especially after you realize you need to buy wire and connectors to extend the cord of that 40Watt, $40 unit from Canadian tire and it might not keep your batteries up. The low angle of the winter sun and cloudy days may (will likely) negate it's usefulness.

$20 for a garboard drain, a little caulking, 30 seconds to drill the hole, 2 minutes to put in three screws.
or .... $2.95US if you buy it here

Click to expand...

Or you can buy the same thing (actually it is a Perko) at Hamiliton Marine for $107.99 USD !!
Thanks for all the advice. I am taking it all to heart, but my mind is made up. This coming week I will drill a pilot hole from the inside at the lowest point in the bilge, let it drain over the winter and install the garboard drain in the spring. That way I can turn off the bilge pump to prevent the pump from draining the batteries.
My biggest problem will be getting a right angle drill into the narrow space between the shaft and the bilge wall to drill the pilot hole. The bottom of the bilge is about a foot below the shaft. I could chance drilling from the outside in, trusting I did all the measurements correctly.
Any ideas or comments on how best to do this?

I've always had at least one boat that gets laid up in freezing weather over the winter. Make sure you start with fully charged batteries, as others have said. I also would go by the boat once a month of so and plug in the charger for a few hours to a day to be sure they stayed topped off. Increasingly marinas don't allow boats to be left plugged in, so leaving them on a charger I think is a disappearing approach.

It is simple to locate holes from the inside to the ourside. Get 2 large rare earth magnets. Tape one on the inside where you want the hole located. Go outside and the outside magnet will easily locate the inside magnet. Confirm they are still in position and mark the outside for the place to drill. Works really great.

Magnets.
Excellent suggestion.
Ideas like this is why I love this Forum.
I'm not ever going to be shy about asking question even if the answer should be obvious.
Thanks for all the brilliant replies.

I bought some large rare earth magnets years ago when I was making a cover for our motorhome windshield. Used 3M tape to glue magnets to the inside of the windshield and sewed pockets in the cover for the outside magnets. I just hold the cover close and the magnets draw the cover into place and hold it. Then I thought that I could use the magnets to find locations in a hull when putting in a through hull or whatever. It works very nicely and takes the measuring multiple times out of the equation, just locate the spot inside and tape a magnet in place.

garboard drain

cold snowy days followed by warm or rainy days said:

A simple and effective drain in the bilge is to drill a 3/8" hole in the hull near the bottom of the bilge. This will drain the winter water. In the spring, simply insert a 3/8" bolt with a nut and washer, and a goop of life-caulk or similar.

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