Major battery service blunder!

[Rustymayes]

2022 Dutch Star 4081 on FL chassis.
I posted a few months ago, that my camping neighbor had cooked his house batteries on a 25 foot trailer and stunk up the camp ground. I was worried for a minute that my batteries had cooked as I had never opened them up to check the electrolyte levels. I unstrapped the batteries and removed the 1/4 turn caps and SOB! the cells were bone dry. I sourced some distilled water and proceeded to top off the cells to within and inch of the service port. Well... fast forward to today and I decided that since my coach is plugged in 24/7/365 I better keep an eye on them. I opened the battery bay and found a mess of battery acid residue and the ensuing corrosion in the bottom of the battery rack. I surmised that I had over serviced a cell or two and the excess boiled over during normal use and charging.
I removed all of the batteries and neutralized the acid spill and will repaint the affected area. As I was removing the batteries and checking the rest of the cells I noticed that these batteries are in fact AGM batteries! I thought AGM batteries were service free and hence were sealed and of course marked as such. NOT!! These batteries have a label with AGM in the model number and another placard with several small print notices none of which say Maintenance Free or DO NOT ADD Water. They say do not disassemble and contains corrosive substances blah blah blah.
I did some digging on the web and found several articles that say that AGM batteries are Maintenance free and do not add water.
They (in Pairs) are holding 12.8 volts so I am drafting off what water that I can and will fully charge and test them before I reinstall them and try to get what life I can as other than them expelling the excess water, they are not showing symptoms of failure.
I thought I would post this in case anyone here might be tempted to add water if they checked the cell levels since the tops look like they are designed to be removed for service.
Also interested in any constructive commentary you guys in the battery world might have.
As an aside, I removed the entire battery drawer assembly to clean up under it and repaint the bay floor and was astounded to find that the mounting frame was only held in place with two bolts on the inside corners of the frame. This allows the whole drawer rack to bounce up and down as you rattle down the road. There were never any holes drilled in the bay floor to accept bolts! Might want to check yours out.

 

[Chuggs]

Interesting...AGM, as you mentioned...in my mind are maintenance free. My Lifeline AGM's have no place to add water. To me...you can have a Maintenance Free batteries...like our chassis starting batteries are. But, AGM. Absorbent Glass Mat. There isn't supposed to be exposed lead plates and a hole for water. Looks like screwy marketing ploy to me.

Flooded lead acid batteries do require a ton of maintenance. I you're charge parameters are set to avoid much evaporation and misting... and you perhaps add a bit of battery delisted, or mineral oil to the surface to prevent splatter...coat all the terminals religiously with anti corrosion spray...they are manageable. But, true AGM's are such a blessing. The only thing I miss, is being able to sample the electrolyte to measure its specific gravity....or maybe not that much.,

 

[Richpatty]

And I agree about the bolts. When I removed my tray to replace with lithiums, I was surprised to see only two bolts holding it in…but to be honest, I think gravity is doing a lot of the work too.

I have an extra tray if you ever want one.

 

[Rustycoach]

Interesting...AGM, as you mentioned...in my mind are maintenance free. My Lifeline AGM's have no place to add water. To me...you can have a Maintenance Free batteries...like our chassis starting batteries are. But, AGM. Absorbent Glass Mat. There isn't supposed to be exposed lead plates and a hole for water. Looks like screwy marketing ploy to me.

Flooded lead acid batteries do require a ton of maintenance. I you're charge parameters are set to avoid much evaporation and misting... and you perhaps add a bit of battery delisted, or mineral oil to the surface to prevent splatter...coat all the terminals religiously with anti corrosion spray...they are manageable. But, true AGM's are such a blessing. The only thing I miss, is being able to sample the electrolyte to measure its specific gravity....or maybe not that much.,

I assume Harris Battery is saving money by using a standard battery frame and case and just installing the AGM cells in them instead of investing in the tooling to build a sealed case. I just think they should invest in better labeling. I can’t be the only idiot that made this mistake. I may be the only one willing to tell about it though

 

[B52Bombardier1]

I'd be asking myself why this battery charge controller boiled my electrolyte. And you have likely shortened the life and the amp-hour capacity of these batteries in a big way. Seeing 12.8 volts on a voltmeter is only part of the health check of your batteries. I suspect that your batteries can no longer deliver their listed number of amps and are in fact, soon to be nearly useless.

A battery "load test" at any well equipped auto parts store will tell if they can still do the job for you.

Rick

 

[Richpatty]

I have never had AGM batteries...but is it normal to open them (if you do) and see them dry? I figure they should something there...no?

 

[Chuggs]

It defies logic. Absorbed Glass Mat, means the electrolyte is impregnated in a glass mat…so having lead plates submerged in liquid electrolyte is by definition a flooded lead acid battery. If you can sample the solution in a hydrometer…it’s flooded.

The manufacturer has somehow misled people by using those three letters in the graphics somewhere.

I would love to Google the manufactures specification sheet for these batteries to see how blatant they were in their deception.

Looks like others are confused as well…

Harris Battery Model Confusion, Specifications?

Since the factory forgot to install my Victron battery monitor, I thought I would tackle it myself.

tab-rv.vanillacommunity.com

I hat to say it…maybe someone got a bunch of battery’s and labels and magically made AGM’s out of Flooded Lead Acid and sold them at a premium. IDK…very confusing.

The batteries on their site, do not appear to be accessible to see inside the cells or add water.

 

[AbdRahim]

Yes the agm’s have caps. Newmar tech said do not touch them.

 

[Rich W.]

I have never had AGM batteries...but is it normal to open them (if you do) and see them dry? I figure they should something there...no?

apparently some do. Mine dont and I’ve never seen that before so it was a surprise to me.

 

[Chuggs]

New to me…

YouTube has a bunch of videos showing how to add water to AGM batteries. New to me…