Charging batteries while in storage

Mdanly · 12-19-2021, 05:15 PM

I have a 2021 Winnebago Forza 34 and going to out it in storage this week. How do I keep the batteries charged? Can I plug in the shore power? If yes, do I leave battery switches off or on? Both chassis and house?

Do I need to buy a maintenance charger? If so, any recommendations on brand and model?

BTW, I live in the Chicago area so cold winter coming.

Thanks so much for your advice

DavidM · 12-19-2021, 05:33 PM

Plug into shore power and leave the use/store or battery disconnect switch on. That will let the shore powered converter charge the coach batteries. And if you have a BIM which i suspect you do, it will connect the coach to the chassis batteries and charge them as well.

Your BIM will typically be a Precision Circuits BIM 160.

David

David

Mdanly · 12-19-2021, 06:24 PM

Thanks I’ll give that a try

BobC · 12-20-2021, 06:26 AM

There are numerous threads on this on many RV sites. One of the most common recommendations, especially in very cold locations is to remove the batteries and store them at home, and using a battery maintainer or trickle charger to re-charge them periodically. You might want to do some reading and make up your mind:

https://www.google.com/search?q=rv+d...client=gws-wiz

I'm concerned that David's method might result in over-charging.

DavidM · 12-20-2021, 06:50 AM

Quote:

Originally Posted by BobC

I'm concerned that David's method might result in over-charging.

The Precision Circuits BIM which connects the coach batteries to the chassis batteries has an algorithm that only connects when the chassis batteries are down to 12.5 volts. That prevents overcharging of the chassis battery.

Then there is the question about overcharging the coach batteries on shore power long term. I will admit to being somewhat concerned about the ubiquitous WFCO 8955 converter overcharging the coach batteries. I don't think its charging algorithm is all that good. Check the coach battery's voltage after a day on shore power. If it is 13.5 V or less you are ok. If higher, maybe I have to agree with Bob.

I use the factory installed 100 watt panel to keep both batteries charged since I don't have shore power at my storage site. It keeps the coach batteries at 13.5 V and the chassis batteries at 12.5+V. I routinely check the batteries' voltages and that is what I see.

It is fairly easy to rig a 50-100 watt solar panel temporarily mounted on the rear or front bumper, whichever faces south so you don't have to rely on shore power.

David

David

David

**creativepart** · 12-20-2021, 06:50 AM

Can you give us more details about your storage setup? Storing at home or in a storage facility? 15 amp shore power or higher? Storing in the open, covered or inside a garage?

Mdanly · 12-20-2021, 06:57 AM

In door not heated, just 15amp service in a storage facility

BobC · 12-20-2021, 07:12 AM

Quote:

Originally Posted by DavidM

It is fairly easy to rig a 50-100 watt solar panel temporarily mounted on the rear or front bumper, whichever faces south so you don't have to rely on shore power.

David

That's exactly what I've done, 50W on the rear ladder and a small solar controller. I have an Amp-L-Start so my starting battery is charged as well.
Unless you already have a bi-directional battery isolator (BIRD), an Amp-L-Start or Trik-L-Start is essential no matter what method you use. I have two 160W panels for the roof but they're not installed yet.

**creativepart** · 12-20-2021, 07:14 AM

Quote:

Originally Posted by Mdanly

In door not heated, just 15amp service in a storage facility

Thanks. Consider this… in my experience the power source in this kind of setup is unreliable and unless you can check on it very frequently I wouldn’t trust it being there with house/chassis power cutoffs left on. If the power there fails you will not know it and the batteries will quickly be discharged. I’d turn everything off and put separate battery maintained on both battery banks. OR I’d bring the batteries to the house and store them on maintainers there.

The power at the storage yard can fail for any number of reasons, including storms that don’t effect you at your home.

I’ve had good luck with BatteryMinder and Battery Tender brand maintainers. But the are many good ones. I doubt there is much to charge if you go into storage with fully charged batteries.

RTrider · 12-27-2021, 07:45 AM

You should confirm, but it is hard to believe your 2021 would have anything but a multi-state charger, so staying plugged in should not be an issue. Yes, you do need to leave the battery connect turned on. In my 2014, we sit in one location for the entire summer plugged in. I don't see any difference from your doing this in storage. We have not seen any premature battery degradation. If the unit is not close to where you live and you want to avoid the weekly trip out to check it, buy one of the remote monitors that will let you know if the power goes off. They have a cellular connection and you can get alerts on your cell phone. Just a thought.

Mdanly · 12-29-2021, 07:42 AM

Thank you for the information

gurroz · 12-29-2021, 07:54 AM

Quote:

Originally Posted by BobC

There are numerous threads on this on many RV sites. One of the most common recommendations, especially in very cold locations is to remove the batteries and store them at home, and using a battery maintainer or trickle charger to re-charge them periodically.

Bob, my concern would be generator maintenance. I go to storage once a month to start the gen and put it under load for 30 to 60 minutes. The gen charges the batteries more than enough to replace any discharge. I much rather deal with a low battery than have generator problems.