winter storage with shore power available

[PEJensen]

Hi everyone. We have a 2019 FC 23 FB that is currently winterized with the negative side of the batteries disconnected. We will soon be able to move it to an enclosed shed that has 20 amp shore power. Question is whether to just leave the batteries disconnected and not plug in to the shore power or to plug in and reconnect the batteries. And whether to leave the switch at the door in the "store" position. Thanks.

[Daquenzer]

Two trains of thought.
1). I kept mine in my pole barn all winter plugged into 20 AMP power. Just make sure the switch is turned to “in use.” It was fine. I just checked the batteries from time to time. Some think this isn’t a good thing since they believe it will cause the batteries to get overheated. But mine did just fine.
2). This year I am keeping my batteries on a trickle charger for each battery from the 20 AMP source. In fact whenever I store the AS I put it on a trickle charger since Interstate batteries last longer when fully charged. So far so good. NOTE it has to get really really cold (-77) to freeze a battery. Since you live in Missouri you wil be totally fine!!! Unless we enter a new ice age. This way you don’t have to keep the switch on “in use” instead you put in “store” mode. The RV will draw some charge, but very very small. The trickle charger works just fine. Note I use 2 trickle chargers, one for each battery. Not sure you need to, but trickle chargers are cheap, and have multiple uses.

I am assuming you have interstate batteries. Lithium batteries store better at about 80% charged. Not sure about AGM batteries. I think a trickle charger would be fine for them as well.

[uncle_bob]

Hi

Trickle charging for months is as likely to kill a battery as leaving it is. Either way, they die eventually. With it hooked to power there is always the chance of a random electrical fault creating an issue ( = fire .....).

Bob

[Daquenzer]

Originally Posted by uncle_bob

Hi

Trickle charging for months is as likely to kill a battery as leaving it is. Either way, they die eventually. With it hooked to power there is always the chance of a random electrical fault creating an issue ( = fire .....).

Bob

Not so. https://www.goldeagle.com/tips-tools...er-maintainer/

That kind of logic also means that running your car constantly destroys the battery or keeping your trailer plugged in while camping without disconnecting the batteries will kill them.

A trickle charger (battery maintainer) doesn’t run when it senses the battery is charged.

[uncle_bob]

Originally Posted by Daquenzer

Not so. https://www.goldeagle.com/tips-tools...er-maintainer/

That kind of logic also means that running your car constantly destroys the battery or keeping your trailer plugged in while camping without disconnecting the batteries will kill them.

A trickle charger (battery maintainer) doesn’t run when it senses the battery is charged.

Hi

If I was selling trickle chargers, I'd write a lot of advertising recommending their use all the time on every battery in every condition. If I could work out a way to get you to buy two or three for every battery you owned, I'd put that in the ad copy as well.

A battery in anywhere near proper condition will not self discharge over the winter to any major extent. Freezing is the only risk you have. Unless the battery is heavily discharged or you are on the dark side of the moon, it's not going to freeze.

Bob

[drbrick]

Use a battery tender - I connect one to both vehicles during the winter because we don't drive enought to keep them charged. Our AS is connected to solar which runs like a battery tender to maintain charge. Alternative is to remove them and store in a warm dry place and check monthly - make sure they don't discharge below 12.6 if they do connect to a battery tender to bring the change up. If left in freezing temp the battery will discharge faster. The above is the voice of 20 year of 6 months of winter dealing with lead acid batteries. Let the disagreement begin

[Ken G]

A battery tender by Deltran is NOT the same as the old timey trickle chargers. I use them on everything - snow plow truck that sits 9 mos. a yr - a Harley whose battery lasted 12 yrs - UTV - misc motorcycles. I highly recommend they even have weatherproof models.

[bibbs]

I like the idea of having things off. I pull the cable off my car when I park for 3 months at a time,

[Life is a Highway]

Ok teams

A trickle charger will destroy a battery a quality battery tender/ maintainer will not hurt a battery.

Originally Posted by Daquenzer

Not so. https://www.goldeagle.com/tips-tools...er-maintainer/

That kind of logic also means that running your car constantly destroys the battery or keeping your trailer plugged in while camping without disconnecting the batteries will kill them.

A trickle charger (battery maintainer) doesn’t run when it senses the battery is charged.

[cazual6]

Here is what I do. Everyone, as you can see already, has their way of doing things. Mine hasn't given me problems.

I plug this Deltran directly to the battery terminals. I leave the switch position to STORE.

Whether this kills the battery or shorten it's life, so what, I'll just go buy another. If you can afford an AS, what's another for buying batteries is my thought. I'm no millionaire, but too much to think about. I have a generator if all fails anyways.

[nipperguy]

As long as you have a multi-stage converter/charger, which I believe the 2019 Airstreams have, you should be able to leave unit plugged in. But, whether you leave plugged in or on a trickle charge, if you have wet batteries, remember to check levels monthly!

[brundom]

I let the solar panels keep it charged. However, when the panels are covered in snow the SunExplorer indicates "charge". Then I plug in until I can clear the panels. Works fine.

[Daquenzer]

Originally Posted by uncle_bob

Hi

If I was selling trickle chargers, I'd write a lot of advertising recommending their use all the time on every battery in every condition. If I could work out a way to get you to buy two or three for every battery you owned, I'd put that in the ad copy as well.

A battery in anywhere near proper condition will not self discharge over the winter to any major extent. Freezing is the only risk you have. Unless the battery is heavily discharged or you are on the dark side of the moon, it's not going to freeze.

Bob

All batteries, regardless of their chemistry, will self-discharge. The rate of self-discharge for lead acid batteries depends on the storage or operating temperature. At a temperature of 80 degrees F. a lead acid battery will self-discharge at a rate of approximately 4% a week.
Battery Basics - Progressive Dynamics

So at 4% a week at 80 degrees if over 16 weeks that battery has discharged 64%.

[uncle_bob]

Originally Posted by Daquenzer

All batteries, regardless of their chemistry, will self-discharge. The rate of self-discharge for lead acid batteries depends on the storage or operating temperature. At a temperature of 80 degrees F. a lead acid battery will self-discharge at a rate of approximately 4% a week.
Battery Basics - Progressive Dynamics

So at 4% a week at 80 degrees if over 16 weeks that battery has discharged 64%.

Hi

The topic at hand is winter storage. Like any other chemical process the rate of self discharge drops as the temperature goes down. A battery that discharges 4% a *week* at 80F is ready for the scrap pile by any manufacturer spec I've ever seen. 4% a month is a more believable number.

Rate drops 2X for every 20 degrees. By the time you get to zero, you are at 2^4 = 16X lower. If you started at 4% a month, 4/16 = 0.25% a month. That's very much in the "forget about it" range.

Bob

[majorairhead]

I have a '19 International and plug in to 50 amp in a garage, no problems so far. Did it all last winter, no problem.

In the '16 Flying Cloud I'd pull the batteries, put 'em in the garage, checked 'em on a regular basis over winter, and put 'em on a battery tender if needed.

[Daquenzer]

Originally Posted by uncle_bob

Hi

The topic at hand is winter storage. Like any other chemical process the rate of self discharge drops as the temperature goes down. A battery that discharges 4% a *week* at 80F is ready for the scrap pile by any manufacturer spec I've ever seen. 4% a month is a more believable number.

Rate drops 2X for every 20 degrees. By the time you get to zero, you are at 2^4 = 16X lower. If you started at 4% a month, 4/16 = 0.25% a month. That's very much in the "forget about it" range.

Bob

A cold battery or a hot battery discharge more quickly. The ideal temp for storing is 59 degrees.

https://www.thoughtco.com/why-batter...weather-607889

Plus a lead acid battery should never discharge below 80% or it will hurt the battery. This is why batteries in an AS that is bought off the lot are notorious for not lasting very long. Mine lasted one year.

The OP should just keep a battery maintainer on it and forget it. It will stay charged and never get over charged.

[uncle_bob]

Originally Posted by Daquenzer

A cold battery or a hot battery discharge more quickly. The ideal temp for storing is 59 degrees.

https://www.thoughtco.com/why-batter...weather-607889

Plus a lead acid battery should never discharge below 80% or it will hurt the battery. This is why batteries in an AS that is bought off the lot are notorious for not lasting very long. Mine lasted one year.

The OP should just keep a battery maintainer on it and forget it. It will stay charged and never get over charged.

Hi

If you read the article carefully, it's not talking about self discharge. It actually notes that self discharge is less when it's cold. Thus it supports the claim that you don't need the trickle charger.

Bob

[Daquenzer]

Let's go right to the horse's mouth; Airstream itself.

"Batteries last longer if they are kept charged, and if you keep your battery stored in your garage or workshop it will encourage you to check on them periodically. Removing the battery also gives you the opportunity to have it tested at a battery supplier and inspected for any damage to the case. You can also check fluid levels in lead acid batteries and fill with distilled water if necessary to cover the tops of the plates.

If you choose to leave your batteries in your Airstream during storage, you must keep them charged. This will require plugging the unit in or hooking up to a charge at least monthly. Batteries should be fully charged when placed in storage and maintained to keep batteries from freezing. Airstream does not recommend leaving your unit plugged in full time during storage. If the battery fails, the converter will try to charge it back up and you’ll end up boiling down the liquid in both batteries."

This is from the last Rivet emailed out yesterday from Airstream.

https://www.airstream.com/blog/how-t..._hsmi=80434232

Conclusion:

1) If you are going to leave them in the Airstream a battery maintainer is a plus. It will keep the batteries fully charged and protect against freezing. Remember if you don't put a disconnect switch in the Airstream will draw current.

2) If you don't put a maintainer on them then you must charge them once a month. And even if you take them out of the Airstream they must be maintained to keep from freezing if left in the cold weather.

Finally, I went to college in South Dakota for 4 years with a car in the parking lot those 4 years. I can tell you those batteries would drain significantly in just a few weeks sitting out in the cold of winter. Since we didn't have battery maintainers to plug in (plus no place to plug in), the only way to keep those batteries from tanking was to periodically drive the car at least every few weeks and charge the batteries. Those that didn't do this; well that's why we all carried jumper cables.

https://www.batterysystems.net/why-b...-cold-weather/

What is the solution?

"Make sure that a battery is kept warm. For example, vehicles residing in a place with snow will do better if they are kept in the garage due to insulation and warmer temperatures. Keep in mind – a general rule of the thumb suggested by US Battery is that for every 15-20 degrees below 80°F, the battery loses 10% of its capacity.

Keep the battery on a trickle charger, especially if the battery is not frequently used. One of the most common mistakes today is leaving batteries stored in a discharged state. When this is done, especially in cold temperatures, a battery can freeze. However, if the battery is kept charged during cold weather, the electrolyte can avoid being frozen and causing unexpected failures."

And my final statement on this thread: even if you put a maintainer on them you need to check them to make sure the water levels are up and that the batteries have the proper voltage. One article I read said it is even good to let them discharge some and then charge them up. When charging the go over 14 volts which helps keeps deposits from building up.