Leaving the house batteries in the chassis for the winter

DrewE wrote:
Even a single stage converter, operating properly with an output of 13.6V or thereabouts, won't boil batteries dry too quickly. Just check and add water as needed (maybe every month, at least until you get an idea for how often it's required).

With a PD 9600 series converter, I top up the battery water once a year, whether they need it or not.

In areas where it's sub-freezing, you can also just fully disconnect the batteries for the winter (after charging them fully) and leave them and they'll be fine...or if they aren't, they weren't fine to begin with. Storing them in a warmer place requires periodic or float charging as the rate of self-discharge is temperature dependent..

I would not recomend or consider disconecting,
bateries will always lose some charge in winter cold and may freeze..

Even in mild weather batts will lose charge over time

I leave battery conected and clean snow of my 80W solar panel to make sure batt is always fully charged..
Works perfect,,but then it does get minus 20 here..
Btw I have AGM maintanance free batt.

free radical wrote:

DrewE wrote:

In areas where it's sub-freezing, you can also just fully disconnect the batteries for the winter (after charging them fully) and leave them and they'll be fine...or if they aren't, they weren't fine to begin with. Storing them in a warmer place requires periodic or float charging as the rate of self-discharge is temperature dependent..

I would not recomend or consider disconecting,
batteries will always lose some charge in winter cold and may freeze..

Even in mild weather batts will lose charge over time

I leave battery conected and clean snow of my 80W solar panel to make sure batt is always fully charged..
Works perfect,,but then it does get minus 20 here..
Btw I have AGM maintanance free batt.

Solar does work well for this, too, if you have it installed and store in a place that's not enclosed/covered.

Batteries will self-discharge much more rapidly in mild weather than in cold. The general rule of thumb is the rate doubles or halves for every ten degree celsius change in temperature. At winter temperatures, it takes months for them to drop below, say, 80% charge. During the summer in Florida, it only takes a week or two or three.

A charged battery will not freeze in anything above genuine arctic temperatures; if you're not storing it in, say, Deadhorse, AK, it's a non-concern if they're charged. A discharged battery will freeze much more readily.

free radical wrote:

I would not recomend or consider disconecting,
bateries will always lose some charge in winter cold and may freeze..

Even in mild weather batts will lose charge over time

I leave battery conected and clean snow of my 80W solar panel to make sure batt is always fully charged..
Works perfect,,but then it does get minus 20 here..
Btw I have AGM maintanance free batt.

My GC-2 batteries stay outside all winter.
I fully charge my batteries in October then disconnect. Come April I top up the 10% charge they lost from the previous 7 months. Have been doing this for 7 years and the batteries are still going strong.

Deleted double post

It is a WFCO WF-8955 PEC. I finally found an owners manual on line and it shows that if the unit is plugged in to shore power and no load is detected it will switch to Float mode which will charge the battery with a trickle voltage of 13.2 volts. When the converter senses a demand it will switchback to absorption mode. The manly shows one of The 3 operation modes as "float mode/trickle charge during storage.
Guess that answers that...

I used to be a "take it inside and store on trickle guy". But with two grp 31's in my boat, my back could no longer deal with them. For the last 10 yrs they have stayed out, disconnected all winter. Never less than 90% come spring. Ditto with my RV batteries - in fact, due to health issues, could not use it at all this year. Went to retrieve what I though would be a dead battery, and even after 12 mos, over a usual Minn. winter AND a pretty hot summer...battery was still at 80%.
Here's a link, scroll down to the chart for lead-acid time vs temp:

https://batteryuniversity.com/learn/article/elevating_self_discharge

If you live in a colder climate, just top off, fully charge, disconnect and forget until spring.

Fully charged, a battery does not freeze until below -74F, which none of us will ever see.....

Winter temperatures require higher float voltages, something no converter that I know of does.

My AGm specs float voltage of 13.6.

If I fully charge it, determined by amperage at absortpion voltage, then float it at 13.5v at 60F overnight. In the morning, when I bump up voltage back to 14.4v+ the amperage it accepts indicate that it somehow discharged slightly with the lower than ideal float voltage.

I'd want the batteries disconnected, periodically charged, not floated continuously at a set 13.2v.

Self disharge of batteries slows considerably in lower battery temperatures, but older batteries that were refilled with impure water might have a high enough self discharge to not make it through winter above 80%, presuming they were put away and disconnected at 100%.

Anyway unless the float/maintenance charger has temperature compensation, i would not leave it plugged in all winter long unless winter averaged within 15F of 77F.

And the Wfco is not to be trusted in any temperatures, imo.

I leave my battery in the rv all winter, i don't plug the rv in to charge the battery because i don't have a smart charger on board, but i do start the rv once a month for at least 30 mins during the winter, and the house battery and chassis battery are 3 years old

We don't have power at our storage site. I started using a portable 100W solar panel to keep the batteries charged up. I didn't have much faith in the cheap charge controller that came with the solar panels as being suitable for being continuously connected to the batteries. So I bought a Bogart Engineering PWM solar charger and wired it to the batteries. Choice was driven by the fact we already had the. Bogart Battery Monitor. The battery monitor tells me how much solar power is being generated and how much power had gone in and out of the batteries.

The portable worked very well over two winters. The SC-2030 is smart enough to not over charge the batteries and I think I've only needed to top up water once over then winter. Even then it was minimal.

This year I installed 200W of flexible panels on the coach roof so I don't have to haul out the portable and have something sitting outside that is subject to being walked off with. I do have a pig tail installed on the solar charger so I can hook the portable in parallel with the two roof top panels.

One unlooked for advantage of having the 100w panel (now 200w) is that if I forget to put the Use/Store switch on the coach into Store I still have enough power to not have coach parasitic loads discharge the batteries. I've seen some folks with small 10w or 20w panels, and am not sure how well they work over time.

Why not get a float maintainer, disconnect the battery ground and unplug from shore power?

Relying on WFCO is similar to relying on "The Check Is In The Mail"