Batteries in winter

Batteries will not freeze if they contain a charge. It's when they go dead that they freeze.

As long as you don't lose converter power for an extended period of time during the extreme cold, as in days/weeks given the power draw, they will be fine.

Agree with mkirsch. We keep our four 6 volt deep cycle in our FW all winter with temps sometimes that low for a few days, but the FW is plugged in. We check them frequently and refill as needed.

rate of self discharge becomes lower as temperatures drop.

I would disconnect the negative post.

next choice would be a trickle charger on a timer set for 1 hour a day

next choice would be the converter--on a timer set for 1 hour a day.

best choice is a solar charging system with a trik-l-start to maintain the chassis battery

My only concern would be if your converter is overcharging them.
Not saying it is, just something to watch out for if you're not certain you have a converter that reliably goes into float or maintenance mode.

Otherwise, they won't freeze. Just like your car batteries.

I also have twin 6v deep cycles and subzero temps . I have a 3 stage converter/ charger and use a weekly timer on the charger set for one day a week . This seems to work just fine as the state of charge never falls below 85 percent with a small 20w load for the battery monitor . You didn’t mention what charger you have . The first winter , before the timer , the charger ran continuously and that worked too .

Keep your wet batteries charged and they will not freeze.

You can go either way as a charged battery will not freeze at temps posted, we store our rigs in our side yard and they are plugged in except when out RVing. We have smart converter or multiphase inverter charger on our rigs and they keep battery bank happy without over-charging.

ReneeG wrote:
Agree with mkirsch. We keep our four 6 volt deep cycle in our FW all winter with temps sometimes that low for a few days, but the FW is plugged in. We check them frequently and refill as needed.

Thanks for all your advice! I just bought them a week ago, I shouldn't have to check the fluids in them for a few months right? I mean they should come properly filled from the store since they're brand new (probably should've checked them before installing them though). The Northern Lites come with the GO Power GP-PWM-30-SB charge controller which is a 4 stage and from my understanding, it goes into float once the batteries are fully charged and equalizes them once a month. I also have 400 watts of solar on the roof in case the power goes out for some reason.

Mammoth501 wrote:

ReneeG wrote:
Agree with mkirsch. We keep our four 6 volt deep cycle in our FW all winter with temps sometimes that low for a few days, but the FW is plugged in. We check them frequently and refill as needed.

Thanks for all your advice! I just bought them a week ago, I shouldn't have to check the fluids in them for a few months right? I mean they should come properly filled from the store since they're brand new (probably should've checked them before installing them though). The Northern Lites come with the GO Power GP-PWM-30-SB charge controller which is a 4 stage and from my understanding, it goes into float once the batteries are fully charged and equalizes them once a month. I also have 400 watts of solar on the roof in case the power goes out for some reason.

They should be ok, but . . . it never hurts to check.

With 480w of solar on my roof, my batteries are always fully charged. You should not need to plug in unless you have your camper and panels covered.