Shoreline or trickle charger to maintain batteries?

[ChrisatUNC]

Hi all,

One month ago I had 30a RV electrical service installed at home to allow us to use the AS as an office with air conditioning when we’re not on the road.

As for the batteries, would you recommend:
1) leaving the shoreline connected and turn batteries to ‘use’ mode to keep them charged, or

2) leaving shoreline disconnected except when needed for office use and instead use a battery maintainer (powered by an extension cord plugged in from garage) for the batteries?

I realize some people live full-time on shore power but wasn’t sure if the electrical panel and/or inverter would wear out faster if shoreline was always connected (even if I didn’t really need it to be connected except to keep batteries charged). I’m not concerned as much about energy usage but instead about not wearing out the equipment. Hope my question makes sense and apologies if I missed a thread where this was covered.

Sincerely
Chris

[Bill M.]

I think it depends upon your power converter and I do not know enough about the ones used to tell you. If it is a true 3 or 4 way power converter it should be okay to just leave it plugged in.

A third alternative is to put the airstream on a timer. Get a 30 amp to 110 conversion plug for the trailer and plug it into a garden timer. Set it to be on 2 hours a day to keep the batteries maintained.

[Halford1]

Either way works. Pressing Store or use button works either way while charging batteries.

You could press "use" button when you are inside the AS, and before you leave for the night, press "store" button.

[ChrisatUNC]

Originally Posted by Halford1

Either way works. Pressing Store or use button works either way while charging batteries.

You could press "use" button when you are inside the AS, and before you leave for the night, press "store" button.

Hm... my does NOT charge the two big batteries when plugged in to shoreline UNLESS I press ‘use’.

To others - am I experiencing expected behavior, or is my AS not operating as it should?

[ChrisatUNC]

Originally Posted by Bill M.

I think it depends upon your power converter and I do not know enough about the ones used to tell you. If it is a true 3 or 4 way power converter it should be okay to just leave it plugged in.

A third alternative is to put the airstream on a timer. Get a 30 amp to 110 conversion plug for the trailer and plug it into a garden timer. Set it to be on 2 hours a day to keep the batteries maintained.

I don’t know the specs of my converter but only that it is the factory -installed unit (from 2016).

Very unique solution with the timer! I’m currently running a dehumidifier using the outlet supplied by shore power (an outlet that works if batteries are in use or store mode) so until I understand why my dehu has to run so much - even though the AS just sits in my yard, unused - I want to leave the power on full-time for the dehu until I get a hold on the source of the moisture.

[azflycaster]

Airstream went to a multi stage converter in 2018 which means that you could cook your batteries if they are charging all the time. I had a Progressive Dynamics in my last 2 trailers and keep them plugged in 24x7 when not on the road with no ill effect on the batteries.

[lsbrodsky]

OP,

AS has done the Store-Use switch a couple of different ways, mostly it seems in trailers newer than yours. My trailer, and yours probably, is wired such that the batteries do not charge from shorepower in the Store position, although certain DC loads are still directly connected to the batteries. In Store, with Shorepower, all AC loads are connected and the converter feeds 12vdc loads. A common practice with the older charger was, when hooked up to Shorepower for extended times, to leave the switch in Store except periodically go to Use to recharge the batteries. It seems, at some point AS figured the new chargers would not cook the batteries and wired the batteries in the circuit all of the time. Posts on the forum indicate most trailers work the way yours does.
Larry

[BayouBiker]

I have a 4 mode charger, plus solar and I use option 1, shore power connected full time, though as others mentioned either way works if the converter has a good charge profile. If you have the WFCO 9800 series those have a decent profile. Airstream started using better converters in 2011 but it varied between then and 2017 so it's best to confirm. Edit: oh this was covered by a previous post....

If you have a poorer quality charger, that applies excessive current and voltage when charged, they will cause the battery to consume water which needs to be replaced frequently or worse damage may occur.

As far as what is best for the batteries, the charge and draw cycle is what ages them most. The deeper the draw, the greater the effect. So disconnecting the batteries altogether or keeping them constantly on a quality charger with excellent store and use modes (13.2-13.6 volts continuous) is best. Next best is to only allow them to draw down just a bit ( less than 2-3% (3 amp hr). Drawing them down by just 10 amp hr daily for a season will reduce the life of the batteries by over 1 year of the 12-15 max potential if you treat them with kid gloves. Then it just gets worse after that. Even going the 50% recommended route once a week say will cut the expected life from 15 years down to 6 years.

Not trying to scare anyone, just trying to explain the rationale so you can make an informed choice about how to maintain batteries.

[ChrisatUNC]

Thanks for the responses here. This makes sense given what I’ve experienced. There is one other wrinkle I’m experiencing: even when plugged in, batteries in store, my fantastic fans (for example) appear to operate by the battery. Because I didn’t know the batteries weren’t charging in store mode I apparently let my batteries get REALLY low. Before I realized the batieres were low I had noticed that my fantastic fans were acting screwy. Once I realized the battery issue and charged them up the fan issue disappeared. I’m currently doing the ‘flip to use every few days for a few hours’ route while I shop for maintainers. Amazon has too many options and I’m getting tired it being bombarded by the ones from no-name manufacturers. I’m hoping there’s one $20-$30 range that’ll do, in case anybody here has a recommendation. I am eager to leave the batteries in the AS since we’re using it every other weekend. Thanks again!

[Hans627]

Hi Chris. Welcome to the forum. It's a great place to learn and share.

As others have said there is no harm done by leaving the AS plugged into shore power.

Best regards!

[AnnaBelle33]

My ‘21 Classic has a multi-stage charger that has a float mode. Once my batteries are fully charged the charger will just maintain them. My storage has a cover so my solar doesn’t see any sun but luckily I have 50 amp in my spot.

[Daquenzer]

You can get cheap battery maintainers, but I bought NOCO GENIUS5, 5-Amp Fully-Automatic Smart Charger, 6V And 12V Battery Charger, Battery Maintainer, Trickle Charger, And Battery Desulfator With Temperature Compensation

Bought it on Amazon. Actually bought 2.

I’ve done it both ways. I just think this particular maintainer will do a better job. And I like the fact it has modes for different batteries.