Leaving on the hard: Batteries OK?

[Zoid]

I am about to leave my boat on the hard in Preveza, Greece, which does not get below freezing, for about 6 to 7 months and had some questions about my batteries. I have wet-cell batteries for my house battery bank. I also have 3x135W solar panels that keep them topped up. I assume because I have solar panels and all power consumption will be turned off that I don’t need to do anything special for them over the winter. Right? The yard offers some kind of service to run the engines every so often, but I’m not sure I need that for the house batteries. I also have a starter battery for each engine (gel). For these do I need to do anything at all? Will they be OK just sitting all winter?

Thanks in advance for any advice!

[Paul Elliott]

Does the start battery have something like an echo-charger so it gets some charge from the panels too? If so the panels will do a great job of keeping your batteries topped off.

Otherwise, a gel battery will self-discharge at about 3% per month, so a seven month storage should be ok.

[Zoid]

The house batteries are wet-cell and they get charged by the panels. The starter batteries are gel (AGM). Will the gel batteries be ok?

[blackswan555]

What solar controller are you using ? You will have to keep an eye on water if it is high on voltage or does not have a decent float setting, Maybe get the yard to check battery water every month ? Other than that , If you have mains power either a smart charger or an "el cheepo" charger on a time-switch may be another option,

Tim

[blewett_john]

My boat has been on the hard for three years with a solar charger. The wet cell batteries are fine. I check them with a battery analyzer frequently.

[Kenomac]

Whatever you decide to do, don't leave the boat plugged in to external power. A friends boat caught fire and sank this way two years ago. Make sure the main breaker panel is disconnected from the batteries. Our batteries don't mind being unplugged for six months.

[Vladis]

Hi,

I myself will place the boat on Cleopatra marina next September 11. I also have 3 80 watts panels but they are flexible and mounted on the Bimini. So I will arrange for one of them to sit on a flat surface of the deck and will make a temporary wiring to the controller and that is it. In 6 years it will be the first time that boat will not stay on water for winter. I hope the shipyard will give me advise on what I shall do!
Regards. Vladis.

[foothillsailor]

I agree to not leave your boat plugged in because of risk of fire. I'm not very electrical tetchy.. And was thinking of leaving the solar panels charging my battery banks but with 270 watts of solar panels I was worried about maybe running my 6 six volt wet cell house batteries dry over the 7-8 months while my boat was on the hard. Rather than re-wiring the solar panels to provide reduced current a good friend of mine suggested just covering some or parts of the solar panels so as to get a reduced trickle charge to maintain the batteries while I am away ...would this work and should it be recommended to the original OP?

[exMaggieDrum]

You absolutely need a good solar charge controller/regulator that will maintain the proper float voltage, otherwise you will dry up the batteries. You may want to hire a company/person who will check on the boat and the batteries in particular on a monthly or 6-week basis.

[hellosailor]

Gel and AGM batteries are not the same. Similar, but different voltage requirements. Either one can sit for six or seven months without being badly damaged but some type of maintenance charge is normally suggested. If your house bank is set up for the right charging regime for wet cells, and it is only connected to your wet cell house bank, then I would suggest the best solution is to buy a small (i.e. 20-30 watt?) solar panel and matching small charge controller to keep the gel battery on a maintenance charge as well.


Having the yard come around to run the engine every once in a while would be good, in theory. But in practice that usually means the least expensive labor, the least experienced man, will be sent around and given a chance to make mistakes while starting and stopping engines. And cooling systems and everything else.


Personally I think I'd rather secure the boat and leave it secured.

[billdre]

I don't know anything about solar panel connections. But I have a wet cell starter battery and two AGM house batteries. Each fall I make sure they are fully charged. They sit in the boat on the hard in New Bedford, MA for 6 months and although they are ready for a charge in Spring they are not overly low and they take and hold the Spring charge fine. This is New England so temperatures are below freezing regularly. Keep in mind, all that chemistry slows down when it gets cold.

[lowey49er]

Your friend is on the right track ,cover two of your three solar panels with a cover and make sure the starter battery is connected to your bank ,( use small jumper leads ,if not), for the number of sunny days you will get during the winter the one solar panel will do just fine and not cause any battery grief,
I do this with my mobile home , where I have four 200watt solar panels and ten 55amp/hour gels in the bank, the batteries are always showing 13/14 volts and I leave the inverter and the fridge/freezer running while I,m away.I also use a 60amp. controller.


Lowey49er,
Lidgard 25,
ExTassie,
living on the Peninsular
in Victoria.

[sailcrazy]

FWIW....we have 4x80w panels providing power to the 6 wet-cell batteries we use for house power (3-2battery banks). Then we use a Duo-Charge to provide charge from the house batts to the starter batt(sealed no-mx batt). Since we've installed this system we've spent 3 years sailing the Medd, laying over on the hard each winter, and now we're on the hard in Puerto Rico. Initially we left all 4 panels connected, but it was to much. Now we disconnect 3 of the 4 panels, and leave 1 panel to charge/recharge the batts via the solar regulator. ....it has worked well for us so far.

[Zoid]

I have a Cristec battery charger with boost/absorption and float charge stages. Shouldn't the float stage be able to manage it without disconnecting panels?

[ramblinrod]

For 6 month lay-up:

In all cases, standard lead-acid batteries (with removable caps) should be topped with distilled water.

In all cases, all batteries should be fully charged.

Options:

Good: Switch all battery switches to "off". (Only works if there are no direct phantom connections (e.g. water sensing bilge pump, stereo memory, etc.). (Caution, damage could occur to battery and boat if rain leaks in and auto "float triggered" bilge pump kills battery.)

Better: Disconnect all battery negative terminals (assures absolutely no load). (Caution, boat could fill with water if rain leaks in.)

Best: Apply solar power float charge (any controller with float stage will do). (Controller must be installed properly to be safe under any circumstance.) (AGM start batteries should be disconnected or charged via echo charger with proper float voltage.) (For a single wet cell a 5 watt panel with no controller will do.)

For greater than 6 month layup, only the "Best" (solar float charge) option is valid. For more than two year lay-up, remove and sell or give away the batteries.

Ramblin' Rod
www.sheenmarine.com