Charging Batteries Over the Winter

[MarysPool]

I was hoping to get some thoughts on maintaining the batteries over the winter. My 250 SLX has 2 batteries. The master battery switch is now turned off (i.e., no power to ignition or accessories). The batteries remain connected in the engine compartment. I was thinking of leaving the batteries in the boat and simply connect an automatic trickle charge to each battery. The boat sits covered on a lift.
Thoughts?

 

[sbw1]

battery storage

I put our boat away with the 4 batteries fully charged. I simply turn off all of the switches and circuit breakers and have never had a problem with battery life. We are now stored inside and heated but I used to store it the same way when it sat inside a freezing building. In your case, I would remove the bilge plug to make sure you do not get a build up of water over the winter and I would make sure there is a good cover on the boat. Trickle charging your batteries all winter could lead to premature failure, depending on the type of charger you use. SBW

 

[Dennis Hoaglin]

I have a 270 SLX w/ 2 deep cycle batteries and noticed the marina left the batteries hooked up after winterizing. My boat is under a Fisher Winter Cover this year so I'll be able to hook up the shore power charger once in January for a day or so and again in March. That's what I plan to do.

Dennis

 

[SearayPaul]

I usually check my battery's charge aroun January 1 and usually they are down a little. I wait for a day above freezing and charge em up and that will hold the batteries until April. Worked every year except the year I left the radio on. I am still trying to blame the battery for that one but the physics do not support that.

Have a great day

Paul

 

[Larry&Leisa]

I never did care for physics


:wink:

 

[thunderbird1]

Last year we followed the same process as sbw1 -- circuit breakers off. The previous season our dealer disconnected the cables from the batteries before storing the boat for us. In both cases, the batteries held nearly all of their charge during the winter.

 

[MarysPool]

Thanks for the feedback all. Simply putting a charge on the batteries once a month or so should do the trick. And I admit, a big motive for keeping those batteries charged is not having to lift the engine hatch without the electric assist. Anyone ever add shore power to a 25' runabout?

 

[Dave S]

An onboard Battery Charger and Shore Power are both factory options on your boat so they can definitely be installed.

 

[chuck1]

Anyone ever add shore power to a 25' runabout?

Yes, I've add shore power, charger, bilge heater, grill, etc to my 240SD. The joke at the dealer was that I was turning her into a cruiser. I've got some pictures on my web site of the options i've done if it will help.

 

[Weekends Aweigh]

A few years back, a boat at our marina sunk at the dock over the winter. The bellows sprung a leak and the batteries went dead from the bilge pumps running. This would not have sunk if the battery charger was left on.

 

[Stray Cat]

If that boat didn't have a wet bar...it does now :smt101

We disconnect the batteries because the C02 detector remains on even when the battery switches are off. Like SBW, we leave them in the boat in an inside cold storage building.

While I buttoned things up where the boat is stored, I kept hearing an alarm beeping from another boat in the building.
Now that can't be good.

 

[thunderbird1]

Re: battery storage

Trickle charging your batteries all winter could lead to premature failure, depending on the type of charger you use. SBW

Is the Guest factory installed charger in my boat ok to leave charging all winter? The charger uses three stages to charge a battery. The final stage is described in the manual as follows:

"When the battery approaches full charge, the charger switches into its third charging stage, gradually reducing he current fed to the batteries to as low as 0.1 Amps. At the same time, it reduces the output voltage to a "Float" or "Ready" charging rate of approximately 13.3 VDC."

 

[searaycruisn]

You really should disconnect the batteries because there is always something drawing on them....like the CO-2 detector.

I disconnect my cables, and the batteries are fine in the spring.

 

[beerman]

I was wodering some of the same questions on batteries. My dealer says to disconnect the batteries and leave them on the boat. As long as they are disconnected nothing will draw them down like the memory on the radio. He said it was easier on the batteries than bringing them inside which would need some charging maintenance during the winter. My only concern is if the batteries will freeze and if that is ok

 

[Dave M.]

Re: battery storage

Is the Guest factory installed charger in my boat ok to leave charging all winter? The charger uses three stages to charge a battery. The final stage is described in the manual as follows:

"When the battery approaches full charge, the charger switches into its third charging stage, gradually reducing he current fed to the batteries to as low as 0.1 Amps. At the same time, it reduces the output voltage to a "Float" or "Ready" charging rate of approximately 13.3 VDC."

I think if you keep the boat in the water, then keeping it on charge is a must. If you keep it out of the water, then you can disconnect the batteries or leave it on your charger. The numbers you quote for your charger, float at 13.3, is fine IMHO to leave all winter. But the cables will of course be connected, so you need to check on it from time to time to make sure the charger is still working. If the charger loses power for some reason, then the residual load will drain your batteries in a week or two or more.

A normal wet cell battery will lose roughly 4% of its charge per month, so disconnecting it for 5 months should leave most of the charge in it. With colder winter temperatures, the discharge rate probably goes down. AGM batteries will normally have a much lower discharge rate, maybe 1% per month.

If you do leave the battery floating on a "trickle charger", I would make sure it does not go above about 13.3-13.5 volts during float. If you float the battery at too high a voltage, you will just boil out the water, and you won't have a battery left in the spring.

Those are my opinions, and I bet it get really cold in Wisconsin in the winter. It is not OK to let the batteries freeze. You need to look up the battery freezing temperature vs state of charge, and see if you are OK. Just google it.

 

[Dave S]

I was wodering some of the same questions on batteries. My dealer says to disconnect the batteries and leave them on the boat. As long as they are disconnected nothing will draw them down like the memory on the radio. He said it was easier on the batteries than bringing them inside which would need some charging maintenance during the winter. My only concern is if the batteries will freeze and if that is ok

If it were me, I would remove them and bring them home and put them on a battery "maintainer" over the winter. That way you won't have to worry about them and they will be fully charged and ready to go in the spring.

 

[comsnark]

For me, the decision tree is simple (if you have outdrives)

1) If boat stays in water, the bilge pumps must be operable (that means batteries)

2) If the ambient can drop below freezing, the batteries need to come off.

3) If the batteries are off the boat, I bring them inside, where the temperature NEVER drops below 55F. Once a month, I put the batteries on a charger to keep them topped off. A slight pain -> 2 jet ski batteries, 3 Sea Ray batteries, 1 BlowBoat battery. 2 chargers. Takes about three days.


If you look at (1) and (2), you see that I really would not want to keep the boat in water in a freezing cliamate (if it has outdrives -> Gotta worry about the bellows seals).

 

[rondds]

i always take the batts out in the winter and stow them in my basement. i check on them once a month with a voltmeter to see if they are losing charge. it's a good way to tell if one is "on it's way out." if you drop to under 11 volts, you can probably expect a let down during the summer. i dont charge them back up until a few days before re-installing. it gets too cold to leave them on the boat all winter. this way, i think i can eek out an extra season (btw, they are regular old fashioned batteries - two group 31s deep cycles and one group 27 starting).

 

[jjssas]

Have five 12 v Deka DP 27 batteries in our SeaRay 410 Dancer. Boat is connected to shore power all the time. Twin 30 amp. Never a problem with batteries holding charge. Batteries about three to four years old and just this week changed out two of them as one cell in one and two in another were very low, eventhough boat started and ran fine. I take no chances. I think if the batteries are holding a charge in the first place, have proper water in them, (mine are the kind you can fill), and the terminals are corrosion free, they should be fine over the winter on a charger, at least mine have been. Good luck!

Court Ship

 

[Salty Dog - LI]

If your boat is stored out of the water for the winter, it's always best to bring the batteries in (so they aren't in freezing weather)- and charge them every few months. Why subject them to freezing and fluctuating temperatures if you don't have to?

If your boat stays in the water, shore power to the charger will keep the batteries trickle charged to power the bilge pumps if the outdrive bellows spring a leak!

If your boat is out of water, but you don't want to hassle with the batteries, charge them up before putting the boat to bed, and disconnect the battery cables to prevent any rogue power draw. Depending on their age, there is no guarantee they'll keep their charge over the winter, or that they will perform as well the next season.

My boat is dry docked for the winter. I take my 27's out of my 270DA, bring them down to my basement, and set them on wood planks (to prevent power draw from sitting directly on the concrete floor). I'll charge them every month or 2, and check the water level. In the spring, I know my batteries are ready for another season!