Battery Storage

[knbrown]

I apologize in advance if this has been covered before. We have a 2015 23' Flying Cloud. I replaced the factory converter with a Progressive Dynamics multi voltage stage converter. We have 20/30/50 amp RV shore power hookups at our house where we park our Airstream. We live in the southwest corner of New Mexico where the temperature will dip below freezing at night (into the 20's and occasionally the teens) but the average winter daytime highs are in the 50's. Is there any reason I can't leave the batteries in the trailer and just keep it hooked up to 30 amp shore power?

[GetawA-S]

Knbrown,
You aren’t delighted to live somewhere with weather like that? Lookin’ for issues?
The biggest risk for a battery is for it to be run down and then exposed to temperature below the freezing point of the depleted electrolyte. Not likely at all for you. If they are lithium without internal heaters, you can’t charge them below 32 F or so.
Do you take the battery out of your car at night? Course not! Relax and enjoy your trailer!
Happy camping!

[uncle_bob]

Hi

Simple / safe / easy answer:

Charge the batteries up.

Unhook the negative lead(s) to the battery(s)

Walk away

Hook back up next spring.

Unless it gets down to -80F, your lead acid batteries will not be damaged. For Lithiums the number is more like -50F.

Having the trailer plugged in all winter means taking all sorts of interesting risks. Much easier to simply not take them.

Bob

[ts8501]

Originally Posted by uncle_bob

Hi

Simple / safe / easy answer:

Charge the batteries up.

Unhook the negative lead(s) to the battery(s)

Walk away

Hook back up next spring.

Unless it gets down to -80F, your lead acid batteries will not be damaged. For Lithiums the number is more like -50F.

Having the trailer plugged in all winter means taking all sorts of interesting risks. Much easier to simply not take them.

Bob

Bob:

Is this also the case for AGMs? (Good to Negative 80). I like the idea of not pulling them, but I do live in Minnesota.

[uncle_bob]

Originally Posted by ts8501

Bob:

Is this also the case for AGMs? (Good to Negative 80). I like the idea of not pulling them, but I do live in Minnesota.

Hi

Yes, fully charged lead acids, AGM or flooded are good to insane temperatures. If you run them flat ( as in short one post to the other and leave it that way) they are good to just below freezing. Since a battery in good condition discharges *very* slowly in the cold, you aren't going to run into much trouble over a normal winter.

You will find all sorts of different numbers for freezing point of a fully charged cell. Some show a -92F freeze point. Those same papers also show a -67F freeze point at 85% charge. They then to to -16F at 62% charged.

https://www.trojanbattery.com/pdf/WP...orage_0512.pdf

It does get cold in Minnesota ( been there ....). I don't recall it ever getting below -40F for a full day. Batteries take a while to cool down ....

Bob

[ts8501]

Originally Posted by uncle_bob

Hi



Yes, fully charged lead acids, AGM or flooded are good to insane temperatures. If you run them flat ( as in short one post to the other and leave it that way) they are good to just below freezing. Since a battery in good condition discharges *very* slowly in the cold, you aren't going to run into much trouble over a normal winter.



You will find all sorts of different numbers for freezing point of a fully charged cell. Some show a -92F freeze point. Those same papers also show a -67F freeze point at 85% charge. They then to to -16F at 62% charged.



https://www.trojanbattery.com/pdf/WP...orage_0512.pdf



It does get cold in Minnesota ( been there ....). I don't recall it ever getting below -40F for a full day. Batteries take a while to cool down ....



Bob

Thank you; this saves me work. I will fully charge the AGMs, and then Pull the negative posts on both batteries. Very simple, very easy.

[richard5933]

Originally Posted by knbrown

I apologize in advance if this has been covered before. We have a 2015 23' Flying Cloud. I replaced the factory converter with a Progressive Dynamics multi voltage stage converter. We have 20/30/50 amp RV shore power hookups at our house where we park our Airstream. We live in the southwest corner of New Mexico where the temperature will dip below freezing at night (into the 20's and occasionally the teens) but the average winter daytime highs are in the 50's. Is there any reason I can't leave the batteries in the trailer and just keep it hooked up to 30 amp shore power?

If you have power available to the trailer through the winter there is absolutely no reason you can't continue to let the Progressive Dynamics unit do its job.

My coach batteries have been connected to a PD converter/charger for over 4 years. They stay that way through Wisconsin winters which are much harsher than what you describe. On the occasional warmer (40F or more) day in the winter, I'll run out and check the water level. Otherwise they get no attention from me at all and are good to go in the spring.

[uncle_bob]

Hi

Risks of keeping things hooked up:

1) Lighting. Might not be a big deal in January, but it could be in the spring. Even with a surge suppressor a nearby hit can create a mess in a plugged in trailer. Of course it hits the trailer, you have a mess hooked up or not.

2) Converter failure. I've had several converters fail and the trailer is only 5 years old. In one case the DC bus went high voltage and took this and that with it.

3) Mice and wires. Mouse decides to snack on a wire ... odd things happen. Some of those things could be really nasty.

4) Converter dries out the batteries.

5) This or that runs into / runs over the power cord. Sparks can fly when this happens. I have empirical data on that.

None of these are high probability items. However each of them *has* happened and there are threads here documenting it happening. Costs of this or that happening could be pretty crazy ( like if there's a fire ... yikes ... ). Better to be safe.

Bob

[ROBERT CROSS]

Our Lifeline AGM's lasted 11 Seasons fully charged/disconnected in the AS.
The BB Lithium's are under the same routine.

Actually there no reason to power the AS thru the Winter storage months, especially if not being used/checked daily.

Another TETO AS option....

Bob
🇺🇸

[ts8501]

Question; after I have fully charged my AGMs, and I have disconnected the negative posts on my batteries, do I need to do anything with the Victron Solar controller?

[richard5933]

Originally Posted by ts8501

Question; after I have fully charged my AGMs, and I have disconnected the negative posts on my batteries, do I need to do anything with the Victron Solar controller?

If you have disconnected the batteries, the solar charge controller is not doing anything. You can just turn off the disconnect/breaker on both the in & out of that if you want.

[uncle_bob]

Originally Posted by richard5933

If you have disconnected the batteries, the solar charge controller is not doing anything. You can just turn off the disconnect/breaker on both the in & out of that if you want.

Hi

..... assuming you *have* a disconnect on the "in" side of the controller. If not, this is a great excuse to install one.

Bob

[ts8501]

Factory installed Victron, so I do not know if the disconnect is on the “in” side or not.

[richard5933]

Originally Posted by uncle_bob

Hi

..... assuming you *have* a disconnect on the "in" side of the controller. If not, this is a great excuse to install one.

Bob

Agree.

There are times when you want to be able to turn off all incoming power, and having disconnects in the proper places make this possible.

On my Victron solar charge controller I followed the Victron wiring diagram. There is a manual battery disconnect between the panels and the controller, and between the controller and the bus bar there is a circuit breaker. With both in place, it's possible to totally isolate the controller from both ends should I ever need to make any tweaks.

[Capt Blue]

Just following along on disconnecting batteries during winterization. I also have AGM's with a solar panel on top. If I leave the AGM's in place, won't the solar panel keep them sufficiently charged? I keep my Bambi outside and it gets slightly filtered sunlight.

[robearl733]

It is simple, if you keep your unit connected to shore power, even 15A circuit, your converter will keep your batteries topped off. A smart converter will have a trickle charge and your batteries will be fine. No need to disconnect anything. During winter I keep my motorcycle connected to a Battery Tender and it keeps the battery safely topped off all winter. Your converter will do the same. If lightening hits near your home it can blow out circuits in your house and trailer connected or not.

[Rich W]

Originally Posted by Capt Blue

Just following along on disconnecting batteries during winterization. I also have AGM's with a solar panel on top. If I leave the AGM's in place, won't the solar panel keep them sufficiently charged? I keep my Bambi outside and it gets slightly filtered sunlight.

We have AGMs with a factory installed solar panel on top and use a storage lot. We've not had any problems and we don't disconnect anything and Use/Store is in Store position. The batteries stay topped off. Just check on them periodically to confirm the voltage

[ROBERT CROSS]

Well...45yrs of bucklenusting was taught me...the best way to 'store' a battery that's not being used.
Charge it fully and leave it alone with NO load.

Bob
🇺🇸

Today....

[Rich W]

As long as the battery remains at full charge, sulfation doesn't occur. The problem is that parasitic loads or even just aging in place will allow a battery to slowly discharge.

My Lifeline AGMs, and the previous set as well (which I still have), drop to 75% charge if I don't keep them topped off with either the solar panel or the charger in the garage.

In my boat I have regular lead-acid batteries. Marine batteries have a 1 year warranty, probably because the manufacturers got tired of replacing batteries that died in the second winter. To avoid that problem I keep mine on a timer to kick off a charger twice a day, to simulate a car that's started and run each day. That has really improved their lives.

So if your batteries will hold a 100% charge without any maintenance, you're in great shape. YMMV