AGM Battery Problem?

DAKC · 02-05-2022, 05:33 PM

2019 Coachmen Galleria 24T: As soon as I disconnect from shore power, the firefly panel begins to flicker and the battery indicator drops goes into the red and reads about 10.4v. Also the Co/propane monitor beeps. When turning on all of the lights (shore power not connected) they start flickering and the battery indicator immediately drops to 10.4v in the red. Perhaps a bad battery ground or dying battery though the battery is only about 21/2 years old. The coach has never been boon docked by us or the previous owner who I know very well so the battery has never been stressed.
After three days on shore power, I decided to try and start the generator again after other failures (disconnected from shore power) and it actually started right up! But alas the generator shut down after 2 minutes and the house battery indicator on the Firefly panel went into the red and the CO/propane monitor started to beep a low battery warning. I have started the generator every month to exercise it. This is the first time we had a problem starting it. I have yet to use it while camping as we always stay at parks. Any ideas?

booster · 02-05-2022, 06:15 PM

Quote:

Originally Posted by DAKC

2019 Coachmen Galleria 24T: As soon as I disconnect from shore power, the firefly panel begins to flicker and the battery indicator drops goes into the red and reads about 10.4v. Also the Co/propane monitor beeps. When turning on all of the lights (shore power not connected) they start flickering and the battery indicator immediately drops to 10.4v in the red. Perhaps a bad battery ground or dying battery though the battery is only about 21/2 years old. The coach has never been boon docked by us or the previous owner who I know very well so the battery has never been stressed.
After three days on shore power, I decided to try and start the generator again after other failures (disconnected from shore power) and it actually started right up! But alas the generator shut down after 2 minutes and the house battery indicator on the Firefly panel went into the red and the CO/propane monitor started to beep a low battery warning. I have started the generator every month to exercise it. This is the first time we had a problem starting it. I have yet to use it while camping as we always stay at parks. Any ideas?

Batteries can be shot in 2.5 years depending on many things so not out of the question.

Probably best to start with putting it on shore power and using a multimeter to check the voltage at the battery and see what it is. Then check it between the plus post on the battery and at a good chassis ground. That will give us you and us an idea of what you are looking at for a problem.

DAKC · 02-05-2022, 08:55 PM

On the Galleria, the battery is in under the chassis in a metal box. I am not sure how I could get to the terminal posts to check the voltage. I have done this before on car batteries, but that was easy access.

hbn7hj · 02-05-2022, 11:47 PM

Quote:

Originally Posted by DAKC

On the Galleria, the battery is in under the chassis in a metal box. I am not sure how I could get to the terminal posts to check the voltage. I have done this before on car batteries, but that was easy access.

That is just a step toward replacing the battery, which you will probably have to do, so you may as well get at it.

SteveJ · 02-06-2022, 12:28 AM

For some good battery info:

https://batteryuniversity.com/

themexicandoctor · 02-07-2022, 07:26 PM

Quote:

Originally Posted by SteveJ

For some good battery info:

https://batteryuniversity.com/

Great site.

And for good AGM Batteries, Lifeline all the way as not only are they superior to other manufacturers, in all areas but price, they will tolerate the Learning Curve of a new RV Owner much better.

Think 7 plus years.

GeorgeRa · 02-07-2022, 08:18 PM

If someone want to know about Fullriver battery inners here it is.

https://www.youtube.com/watch?v=huNSJFaqkC0

quincyry · 02-10-2022, 05:56 PM

I have a 2021 Coachman Galleria which had similar problems. I replaced the battery but the problems were not solved. In my case the problem, was the auto reset breaker installed under the van near the battery. On my van there were 2 breakers ...a 250 amp to the inverter and a 120 to the B+ to the load center. The generator start was connected directly to the battery which was an error. The Generator should be connected after the breaker. Both breakers were replaced with manual reset breakers. The auto reset can appear to have a connection but as current flows through the breaker, the breaker heats up and breaks contact. I have reviewed utube video of the auto rest breakers vibrating between contact and no contact.I replaced all the auto reset breakers.

hbn7hj · 02-10-2022, 09:23 PM

Quote:

Originally Posted by quincyry

The generator start was connected directly to the battery which was an error. The Generator should be connected after the breaker.

All generators I have dealt with are connected directly to the battery. If you have a breaker able to handle a generator start surge then it is the safer way.

quincyry · 02-10-2022, 10:07 PM

Thanks for the input on generator wiring. The breaker replacement solved the problems listed in prior emails.

booster · 02-10-2022, 10:40 PM

Quote:

Originally Posted by GeorgeRa

If someone want to know about Fullriver battery inners here it is.

https://www.youtube.com/watch?v=huNSJFaqkC0

Fullriver was on my list of final contenders, but when I went to check sources there weren't any around back then. Only through Canada in some way. TPPL so would have very low end of charge tail amp requirement. Possibly around .1%C.

GeorgeRa · 02-11-2022, 12:06 AM

Quote:

Originally Posted by booster

Fullriver was on my list of final contenders, but when I went to check sources there weren't any around back then. Only through Canada in some way. TPPL so would have very low end of charge tail amp requirement. Possibly around .1%C.

I will likely repeat same batteries when mine are done.
https://invertersrus.com/product/ful...IaAmqeEALw_wcB

DAKC · 02-23-2022, 10:02 PM

Well apparently my AGM battery is toast. It reads 9.6-10v after being on charge for many days. I am now looking at replacing the battery with perhaps three Battle Born's which would be located inside the Galleria. I have also recently found that a possible replacement could be a RELiON RB300 12V, 300Ah battery which would be a "drop-in" to the location of the current AGM battery. For lithium, I would need to replace my BIM and solar controller which does not have a lithium setting. Does anyone have any thoughts on either of theses options, or others?

Sensfan · 02-23-2022, 11:51 PM

Quote:

Originally Posted by booster

Fullriver was on my list of final contenders, but when I went to check sources there weren't any around back then. Only through Canada in some way. TPPL so would have very low end of charge tail amp requirement. Possibly around .1%C.

In June 2021 we replaced the two original US2000 6 volt AGMs on our 2012 RT Ranger with two Fullriver DC224-6 (224AH). We do not have a proper battery monitor, however after the first season of usage, it appears that the available off-grid time between charges is comparable to that of the original batteries when they were new, which was/is 2.5 to 3 days.

DAKC · 03-04-2022, 07:12 PM

Resolved & Update on 2019 Galleria AGM battery problem: I crawled under the coach for the fifth time (ouch) and thought I would check if the bolts on the terminal posts were tight. Being very careful, I tried to tighten the positive terminal bolt and sparks flew out from one of the cables where it lays against the steel battery bracket. After close examination, it appeared to me that there was a strong possibility that just where the cable lug is connected to the cable, it had been rubbing against the edge of the steel strap and the edge of the strap cut through the insulation due to normal vibration of the coach causing a short. There are three positive cables connected to the positive terminal. One of them laid tightly against the sharp edge of the metal strap. It is surprising to me that the manufacturer connected three cables directly to the battery terminal post rather than using a positive bus bar. In fact, the negative battery terminal has four cables connected directly to the negative terminal. Due to access challenges with the battery and tight quarters under the coach, I opted to not try and loosen the positive terminal bolt to realign the cable (as the negative was still connected and barely accessible). Instead I pried up the problem cable and lug and slid a piece of hard, non-conductive plastic between the cable and the battery bracket. I then waited two days for the battery to be fully charged. Afterwards, the battery reading showed 13.4v. I then disconnected from shore power and all seemed normal. The inverter was also running, a good sign. I was also able to start the generator and ran the A/C for the generator’s monthly exercise. Being unable to start the generator is what originally identified a battery problem. Please see the photo of the battery and cables. If anyone can identify the cables with a “??”, please let me know. Other Galleria owners with an AGM battery should check their cable connections for a possible similar problem.

avanti · 03-04-2022, 07:49 PM

You should seriously consider putting an MRBF fuse on each positive terminal.

F3.JPG

F1.JPG

folivier · 03-04-2022, 08:40 PM

Those 2 cables marked with ? possibly go to the isolator/separator under the hood.

GallenH · 03-04-2022, 09:29 PM

Quote:

Originally Posted by avanti

You should seriously consider putting an MRBF fuse on each positive terminal

Attachment 12568

What A rating would you suggest?

avanti · 03-04-2022, 10:21 PM

Quote:

Originally Posted by GallenH

What A rating would you suggest?

I used 300A, But it really depends on your wire size.

DAKC · 03-05-2022, 01:59 PM

Thanks for the input on the breakers. If I run into another problem, I know what to check next. As you know, access under the coach is very challenging. How did you even get to the breaker near the battery without putting the coach on a lift? Do you know where all of those cable go shown on my picture?

You may also like: