Battery Charger

[Ed Brownfield]

Nothing seems to be simple these days. I am a new AS owner (2015 FC) I understand from reading the post that if I store the AS for long periods like I am getting ready to do (six months) that I should remove the batteries and keep them charged. OK, here are my questions what battery charge should I purchase. I called Battery Tender and the person on the phone said that she needed to know whether the two batteries were wired in parallel or in series. She said that she also needed to know the size and AMP hours of each battery before she could recommend which battery tender (charger) to purchase. I do not know the answer to either of these wiring questions or the battery size question. I have a 2015 Flying Cloud 28 ft. with two batteries. I want to purchase a tender that I can keep plugged in my trailer is stored away from my home. I do not intend to keep the trailer plugged in to shore power I plan to keep the battery tender plugged in and hooked to the batteries. Is there a charger that I can keep attached to both batteries or do I need to purchase two chargers? Your knowledge and help are greatly appreciated!!!!

[lsbrodsky]

Your wishes are a bit confusing because you stated that you do not intend to stay plugged in to shorepower. Your battery tender needs AC power so it will have to be plugged in to some shorepower, but maybe I missed your point.
Frankly any tender sold by Battery Tender will work for you if your batteries are fully charged before you connect the tender. They have higher amperage chargers that will also charge a battery but if you want to just maintain an already fully charged battery, any of their smaller ones will work. Having said that, I dislike Battery Tender because one shorted out on me just sitting there doing its maintainer thing. After that I moved to CTEK and have been happy.
If your trailer is outside, you can just use a small solar panel. I do that with my truck stored outside.
One small catch is that your batteries are in parallel so any charger or tender is not going to perfectly charge both batteries. But if both are the same age and have seen the same service, this is not a big deal.
Larry

[Burnside Bob]

You should have two 12V group 24 Interstate SRM 24 deep cycle Marine/RV batteries. They will be wired parallel and each is rated at 84 Amp/hours for 168 Amp/hours total.

You might check to make sure this is what you have, but I believe these are the standard factory issue.

Here's the specs for the Interstate SRM 24 from a battery retailer:

Interstate SRM-24 Deep Cycle Marine & RV Battery 550 CCA

[Trailbob]

When my trailer is charged up, I use the Battery Tender 1.25 amp model to maintain it during storage. The batteries stay on the trailer (all winter), with the Battery Tender pigtail hard wired to them. I have the original factory Interstate group 24 batteries, wired in parallel. I have used the smaller Battery Tenders on boats and motorcycles for years. That said, there is probably better technology out there now, like CTEK that was mentioned in an earlier post, which I would try if I bought another one.

[Wayne&Sam]

I use a BatteryMinder model 12248. I leave the batteries in the trailer, put in storage mode. I leave it that way all the time it's in storage. I put a pigtail connector on the batteries so I can just plug the charger in as needed.

[sgschwend]

Ditto with Wayne&Sam, Battery Minder 12248, in my case full time use, no other power supply, perfectly quiet.

[Chrisy]

So if they are in parallel you only hook up one battery?

[LyleRussell]

If there is power where the trailer is stored why can't he just leave it plugged in and use the built in AS charger to maintain the batteries. No hassle at all.

[n2916s]

Because the converter Airstream uses is a dinosaur. A single stage unit that will overcharge the batteries, ruining them in short order.

Mike

[Ed Brownfield]

Originally Posted by Trailbob

When my trailer is charged up, I use the Battery Tender 1.25 amp model to maintain it during storage. The batteries stay on the trailer (all winter), with the Battery Tender pigtail hard wired to them. I have the original factory Interstate group 24 batteries, wired in parallel. I have used the smaller Battery Tenders on boats and motorcycles for years. That said, there is probably better technology out there now, like CTEK that was mentioned in an earlier post, which I would try if I bought another one.

Trailbob, thanks for your good information! I bought the Battery Tender Plus 12 V - 1.25 amp today! I can't leave the batteries in my tailer because my trailer is stored in a commercial storage facility without access to electricity. I plan to bring both batteries home for the winter and keep them attached to one or two battery tenders. When i bought the Battery Tender the sales person at O"Reilly's who sold it to me thought that I probably needed two Battery Tenders one for each battery. Is that correct or is there a way to connect both batteries together and use one Battery Tender? Is there a problem leaving the battery attached to the Battery Tender for extended period of time; say three or four months? The package says that it "automatically switches from full charge to float automatically". Many thanks for sharing your wisdom

[n2916s]

Just swap the battery tender between the two every couple of weeks and you will be fine.

Mike