Winterizing batteries

gwekins · 01-08-2023, 10:19 AM

Should we be removing our batteries from our coach when we store for the winter and moving them to a location where they will not freeze?

We are in the process of responding to completely dead batteries (coach and chasis) after about six weeks of winter storage. Our dealer winterized the coach, and she is stored in an enclosed, unheated garage about 10 miles from our home. We did have a couple of weeks of severely cold weather in December (as low as -9).

We have read that some "newer" motorhomes can be left plugged in when in storage. Our manual says not to leave the coach plugged in, so we did not. We did turn the batteries off at the toggles over the doorsteps.

We have a 2017 Winnebago Sightseer 36Z.

**Eagle5** · 01-08-2023, 10:45 AM

Hi gwekins,
If you have lead-acid regular type of batteries, then as long as they are connected to a battery maintainer, then they do not need to be removed, no matter how cold it gets to be.
By the time I received my 2019 Minnie Winnie in January of that year, Winnebago chargers were designed to keep a maintenance current on the house batteries.
With your motorhome plugged into shore power, check the voltage on your house batteries. You should see this:

13.x to 15.x volts = Just plugged into shore power, and the higher the voltage, the more the batteries were depleted
13.05 volts, give or take = batteries fully charged and on maintenance voltage.

If these are the voltages you measure, then you do have an automatic battery maintainer in your 2017.
My Minnie Winnie engine-start battery is not connected to shore power to be recharged, so I purchased these two items:

and plug it into one of the motorhome's interior 120 VAC outlets and a 12 VDC cigarette lighter. That way, all three of my batteries are at the ready!
Thanks, Eagle5

**Eagle5** · 01-08-2023, 10:58 AM

... additional ...
You also need a good Multimeter & test equipment; here is a suggestion for that:
Klein Tools 69149P Electrical Test Kit
Thanks, Eagle5

dkoldman · 01-08-2023, 12:03 PM

If I knew temperatures where dropping that low, I would not only plug in, but add a small ceramic 1500 watt heater inside the RV.

I would love to know why WBGO says to not leave it plugged in? I can only assume some legal liability concern, but maybe someone else knows. i.e you don't want to leave AGS on if stored inside

My theory is this, I have very special converter charger made by Progressive dynamics and I will always use it to charge my batteries if needed. I have two AGMs that I added after dumping the FLA NAPAs. My batteries have never been below 12.5vdc. I don't have Solar top off nor external chargers.

If you do what I do, make sure the House Switch is in USE mode and everything else is off.

FWIW, I play around with stuff like this and I have gone 6 weeks with House Battery Switch OFF and not plugged in, and my batteries were sitting at 12.6 vdc 6 weeks later. So I don't have appreciable parasitic drain. Sounds like you do, you may wish to find it and correct, because if the battery switch is OFF it should not be parasitic drain even though we know it happens.

**Eagle5** · 01-08-2023, 03:51 PM

I just reviewed my 2019 Minnie Winnie Owner's Manual and I found the exact same statement which is also in the 2017 Sightseer Manual:

NOTE: Do not leave the shoreline plugged in during storage. Follow regular battery inspection and maintenance.

When I took delivery of the Eagle5 in January of 2019, I specifically asked about battery maintenance voltage being provided by the Power Center, and Art (the Mechanic at Roy Robinson) told me that it was just fine to leave it plugged-in indefinitely. I have done so for four years now.
In retrospect, I believe Winnebago has that statement in there as a Liability Protection to themselves. Of course, you must still verify that (once the batteries have had time to fully-charge) you are running at about 13.05 VDC ±0.10.
Thanks, Eagle5

Oneilkeys · 01-08-2023, 05:22 PM

When I bought my 2020 Travato, the starting battery was not charged by the solar panels. So that I did not have to constantly recharge the starting battery, I installed a BIM and the solar panels easily keep all three batteries at full charge. This winter, I moved further north in Florida so I had my first instance of temps below freezing in 32 years. While I was not worried about batteries freezing, I was very worried about the water in my Truma freezing and destroying the unit. With only three days of below freezing temps, I decided to turn the Truma furnace on to 50 degrees for these three days and empty all the tanks. . At the end of the three days, all batteries were still fully charged and I used a minimal amount of propane. Now I can take the Travato to the Tampa RV show without having to de-winterize it.

**creativepart** · 01-08-2023, 09:38 PM

I like Eagle5’s 2nd post - disconnect the batteries and put a battery maintainer on them. Then the worst that can happen is the power goes out and the maintainer stops working for a while. Leaving the coach plugged in when you can’t check on it frequently sounds super risky to me. RV Converters are not really “battery maintainers.”

The reality is that even with the disconnects off your RV’s batteries will go dead in short order if you do not have some sort of trickle charger unless you physically disconnect the batteries OR unless you visit your RV regularly and use those visits to recharge your batteries.

It can be a hard and expensive lesson to learn. That is for certain.

Marine359 · 01-09-2023, 01:31 AM

NOCO Genius 10 works great with any battery type. $100 on Amazon. It does condition a battery as well as maintain.

dkoldman · 01-09-2023, 06:48 AM

The Progressive Dynamics InteliWizard does not only maintain, it determines when you need to be at a Maintain voltage, or any of the other stages for that matter.

With that said; surely if you disconnect everything you have the least risk, but the operative word may be "Storage" how it is defined by each user or use case.

I store my RV every time I park it. I never know when I may use it again; but 6 weeks is about the max. 3 to 4 weeks may be average? But it is ALWAYS in USE Mode; Plugged in 75% of the time (exceptions being lighting storms, when I am testing how long it can go without a charge, or not parked at it's regular storage location.

By WBGO's liability induced policy; if I had a RV and I needed to store say in Detroit MI and I would not be able to make it to Detroit for 6 - 8 months, I would not only unplug shorepower, remove batteries, but also perform all of the long term storage procedures for my generator.

IMO, the RV legalese can sometimes make RV ownership more difficult than it needs to be. My money says the #1 cause of a defective RV batteries are because misguided RV owner unplugged SP and inadvertently drained the batteries to defective conditions. The cure can be an external charger assuming no solar, but it could also be to find out why did it drain if in storage mode?, or as in my case keep it simple let the IntelliWizard care for your batteries. Some high end AGM mfg will not directly sell you their batteries unless you can confirm you have a proper computer programmed charger like the the Inteliwizard.

For OP; was the intent of WBGO's definition of Storage needed in the User's case? I have Disconnect Switches (if necessary) and removing my batteries will never be a practical option unless I had Lithium ( I don't).

Going on 4 years with new RV and I have never had a low battery issue but it seems to be a topic that surfaces over and over again. Never heard or read the post where OP was complaining where he was running converter and he came back to his coach with completely dead batteries.

Jim_HiTek · 01-10-2023, 03:47 PM

For flooded cell batteries...

Having spent 3 winters in Fairbanks Alaska, I can tell you that if you have healthy batteries, because of the acid, they are good to -74F. Mine did just fine for months at -40 to -55 and occasionally to -65. So, yes, to answer your question, you can leave them sitting out in the RV over the winter BUT, you need to remove the vampire loads that would discharge them to quickly, by removing the GROUND WIRES. And for the 6 Volt batts, remove the jumper(s) between sets (or the main ground wire...whichever is easier).

They have a self discharge rate but I'd service them, make sure they were fully charged, then disconnect the grounds on mine in late October and reconnect in mid May and they'd usually be at around 11.5 Volts. I had new batts and old batts and they all survived. Charged them up in the spring by reconnecting the grounds, jumping the chassis battery set with my car for around 10 minutes, and then starting the RV. Let the alternator do the rest.

No need for expensive solutions when you can just disconnect the grounds. I always keep a wrench and a pair of gloves in the batt compartment...takes all of 2-3 minutes to disconnect all the batts from ground or each other.

Ray,IN · 01-10-2023, 07:11 PM

Quote:

Originally Posted by Jim_HiTek

For flooded cell batteries...

Having spent 3 winters in Fairbanks Alaska, I can tell you that if you have healthy batteries, because of the acid, they are good to -74F. Mine did just fine for months at -40 to -55 and occasionally to -65. So, yes, to answer your question, you can leave them sitting out in the RV over the winter BUT, you need to remove the vampire loads that would discharge them to quickly, by removing the GROUND WIRES. And for the 6 Volt batts, remove the jumper(s) between sets (or the main ground wire...whichever is easier).

They have a self discharge rate but I'd service them, make sure they were fully charged, then disconnect the grounds on mine in late October and reconnect in mid May and they'd usually be at around 11.5 Volts. I had new batts and old batts and they all survived. Charged them up in the spring by reconnecting the grounds, jumping the chassis battery set with my car for around 10 minutes, and then starting the RV. Let the alternator do the rest.

No need for expensive solutions when you can just disconnect the grounds. I always keep a wrench and a pair of gloves in the batt compartment...takes all of 2-3 minutes to disconnect all the batts from ground or each other.