A Few Questions about Batteries Please

[Stews]

I've bought my Classic new three years ago. AGM batteries with solar. The first two years stored on a lot in Fort Meade, MD. The second winter it got so cold that they went to zero, so I took them out and home on a trickle charger. Retired to WA State and last winter on a trickle charger. I have a barn now to store the trailer in full time, but I only have regular household outlets 110 volts so far. I have tried to charge using doglegs from the 110 outlet before, and it went up to 100 percent after a couple of days. My plan was to just give it a 110 feeding during the summer when we weren't out camping. Now it seems the 110 will only get them up to 60 percent or so.
Questions:
1. What is the average expected life of AGM batteries? These are 3 years old and they have gone to 0% a couple of times.
2. Can you charge batteries using 110 via doglegs?
3. I have a battery charger. Can I charge one battery at a time while they are hooked up in the trailer? Would that be a good idea? Would it do damage?
You're sage advice would be very appreciated by this Newby.

[lsbrodsky]

Once you have taken the battery to 0 you have shortened its life, twice, even more so. I used to get 5-6 years on AGM's that had heavy cycling but I suspect at 3 you are done.
I do not know what a dogleg is? You can plug your trailer into a 15-20 amp outlet with an adaptor and that is plenty for the onboard charger.
Or, you can connect the batteries to a battery maintainer over the winter. Lots of choice on Amazon or Walmart or Autozone. If you take care of your batteries, you should not need a regular external charger.
Many threads on the Forum about battery disconnects, winter storage, etc.
Larry

[pteck]

Originally Posted by Stews

Questions:
1. What is the average expected life of AGM batteries? These are 3 years old and they have gone to 0% a couple of times.
2. Can you charge batteries using 110 via doglegs?
3. I have a battery charger. Can I charge one battery at a time while they are hooked up in the trailer? Would that be a good idea? Would it do damage?
You're sage advice would be very appreciated by this Newby.

1) Battery life is always subject to use and treatment. Running any battery down to 0% for any duration significantly compromises them and if not immediately corrected is a nail in the coffin. Based on your description, they are done. Even if you can charge them, they will not hold any meaningful capacity.

2) I'm not exactly sure what you mean, but if you're talking about putting 110V AC wires directly to the battery poles (batteries are DC), absolutely not. Always requires a charger to properly tender a battery.

3) Yup, batteries can be charged concurrently while they are being used. You likely have a converter onboard the trailer which makes a good charger. Some are not as good at conditioning batteries for long term storage. This is where a common and cheap automotive/RV battery float charger/battery tender can help. Or you can upgrade your converter to a multi-stage unit that is better at charging batteries (AGM profile included) long term. Some older converters are known to hold the batteries at too high a voltage long term causing them to prematurely loose all their electrolyte and die.

[Bill M.]

You need new batteries. With that trailer you should be able to just leave the trailer plugged into a 110 outlet. Battery should maintain. I assume that is what you mean by dogleg?

[OTRA15]

You may find helpful information in the various threads in the Batteries etc. sub-forum:

http://www.airforums.com/forums/f449/

Also, this Battery School site is a good background read on RV batteries:

http://www.batteriesnorthwest.com/batteryschool.cfm

It is probably time for new batteries, if you want them to be dependable IMO.

Good luck,

Peter

[Stews]

I'm pretty sure a dogleg is the electrical adapter you use that looks like a dog leg to power down from 50 amp to 30 amp or even down to 110 volt.

[Alumaholic]

I am pretty sure you mean "Dogbone" as in "Dogbone Adapter"
I am also very sure your batteries are toast.
Never ever let batteries discharge all winter, Stews. I bring mine home and keep them hooked to a battery charging station all winter.
In the summer I leave them in the Airstream with the battery isolation switch off. Every three weeks I bring them to full charge.
Properly maintained you can run a pair of batteries for 4-6 years. Other variables make it impossible to predict precisely exactly how much service you will get.

[uncle_bob]

Hi

How to properly care for lead acid batteries (this includes AGM's):

1) Don't let them get below 50% charge level ever. One way to look at this is 12.0V.

2) Never store the trailer off line without fully disconnecting the batteries. That involves pulling the batteries / installing a custom switch / pulling wires off the batteries.

3) If you *do* store the trailer connected to shore power, a timer switch is a really good idea. There are other alternatives, they also get a bit complex.

Properly cared for AGM's will last for a lot of years (like 5 to 10 years). Abuse can easily kill them in under a year.

Totally off topic: Not winterizing your trailer in a cold climate also is a bad idea .... Running batteries flat all winter is pretty much the same sort of thing.

Bob

[drbrick]

Does anyone have information/usage/experience with Silicon Dioxide ULL Batteries (SiO2)?

http://azimuthsolar.ca/product/ultra-long-life-battery/

[jeffmc306]

Originally Posted by Stews

I've bought my Classic new three years ago. AGM batteries with solar. The first two years stored on a lot in Fort Meade, MD. The second winter it got so cold that they went to zero, so I took them out and home on a trickle charger. Retired to WA State and last winter on a trickle charger. I have a barn now to store the trailer in full time, but I only have regular household outlets 110 volts so far.
Questions:
1. What is the average expected life of AGM batteries? These are 3 years old and they have gone to 0% a couple of times.
2. Can you charge batteries using 110 via doglegs?
3. I have a battery charger. Can I charge one battery at a time while they are hooked up in the trailer? Would that be a good idea? Would it do damage?
You're sage advice would be very appreciated by this Newby.

Stews, as others have said, battery life depends on many factors. Since they’re AGM’s you don’t have to worry about low water level which kills standard lead acid batteries. Other factors are if the voltage is allowed to go too low for an extended time and possibly froze if the temp got below freezing.

It’s possible your batteries suffered an extended time of under voltage and are damaged. You might be able to save them with a PulseTech charger-maintainer that can de-sulfate batteries with their patented technology. They’re used by military and commercial applications as well as consumers. They are not inexpensive but neither are AGM batteries.

The XTreme X2 will charge / pulse two batteries at a time which is why I bought it. Photo is from our FC23FB Interstate batteries but it works with AGM’s as well. https://www.pulsetech.net/
Good luck with yours!