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Topic: My AGM's are not holding a charge (Read 466 times) previous topic - next topic
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My AGM's are not holding a charge
Fully charged then to shade camping and within 24 hours the AGM batteries are at 10.3 to 10.7 volts.

This is a new rig.  I don't have a battery monitor yet. I'm on the southern Oregon coast at Bandon.

The refrigerator won't stay lit due to the low voltage. I'm idling the LD right now trying to add juice.

Not a happy camper.

Suggestions?

UPDATE
I ran the coach and got them charged a bit. Hopefully enough for the fridge until the morning.

This is actually the second incidence. The first should have drawn red flags with me. On this trip about a week ago at Panther Flats I noticed the water pump was lagging. We were not plugged in and in the shade as now.  I barely got the generator started but did as the volts read in the mid 10's. After an hour and a half of generator they were back up.

I hope it is a bad battery situation rather than some draw going on.
I also hope that maybe Coos Bay has batteries... and that my cost nil as we just purchased this motorhome.
2021 Mid Bath
Re: My AGM's are not holding a charge
Reply #1 –
Loose battery cable?
Linda B
Green 2021 RB
2022 Ford Maverick toad
Re: My AGM's are not holding a charge
Reply #2 –
Did you run the heater?
2013 31' Silver Twin Bed
Semi-retired 6/21....
Re: My AGM's are not holding a charge
Reply #3 –
1) You are under warranty.  Call the factory or bring in a road technician if LD pays for it.  Why beat your brain? 

2) If #1 not possible, and you have a multimeter, place it on battery + & -, disconnect input power, solar and generator and see if voltage goes down.  Make sure battery terminals are tight per previous comment from Linda B.  If voltage goes down over 10-15 minutes something may be draining it or battery is bad.  If no drain found call battery manufacturer and describe problem.  They may be able to verify bad battery.

Ron
Ron and Linda
Ada Michigan
Re: My AGM's are not holding a charge
Reply #6 –
Quote from: tedeboy  - 
Yes but not a lot.

I'm guessing we need a bit more information.  For example, have you been in the same spot (shaded) for a few days using power including the heater (which everyone will tell runs the batteries down quite a bit).  If you're not getting a full charge from the solar panel(s) then you're going to need to fire up the generator to get them charged.  Of course if you're mobile and heading to a new spot then driving will charge as well.  Try to find a spot with that will allow your solar panel(s) to work to their full capacity. 

Bill
2013 31' Silver Twin Bed
Semi-retired 6/21....
 
Re: My AGM's are not holding a charge
Reply #7 –
Quote from: pdl2win  - 
I'm guessing we need a bit more information.  For example, have you been in the same spot (shaded) for a few days using power including the heater (which everyone will tell runs the batteries down quite a bit).  If you're not getting a full charge from the solar panel(s) then you're going to need to fire up the generator to get them charged.  Of course if you're mobile and heading to a new spot then driving will charge as well.  Try to find a spot with that will allow your solar panel(s) to work to their full capacity. 

Bill

With my previous LD I didn't have solar.  I could use the heater and other items for at least 3 days with my Trojan  T-105+ batteries before needing a charge.

I pulled into the shaded campsite fully charged. Within 24 hours the fridge was shutting off. I checked the volts and it was alarmingly 10.5. I took a meter outside across the terminals to confirm and it was 10.5 as shown on my solar controller.
2021 Mid Bath
Re: My AGM's are not holding a charge
Reply #8 –
Quote from: tedeboy  - 
With my previous LD I didn't have solar.  I could use the heater and other items for at least 3 days with my Trojan  T-105+ batteries before needing a charge.

I pulled into the shaded campsite fully charged. Within 24 hours the fridge was shutting off. I checked the volts and it was alarmingly 10.5. I took a meter outside across the terminals to confirm and it was 10.5 as shown on my solar controller.

Yikes...as mentioned above I'd call both the Mothership and the Battery Customer Service line

Good luck.....what a PIA!!!

Bill
2013 31' Silver Twin Bed
Semi-retired 6/21....
Re: My AGM's are not holding a charge
Reply #9 –
Ted, my *uneducated* guess is that your batteries are bad. Your rig may be new, but I think this was the factory demo, wasn't it? Who knows how often those batteries were depleted or left in an extended state of discharge? The folks at LD should give you a new pair of batteries if they delivered it with batteries that were marginal at best.

Steve K
Steve K

2003 Mid-bath
Re: My AGM's are not holding a charge
Reply #10 –
Quote from: Steve K.  - 
Ted, my *uneducated* guess is that your batteries are bad. Your rig may be new, but I think this was the factory demo, wasn't it? Who knows how often those batteries were depleted or left in an extended state of discharge? The folks at LD should give you a new pair of batteries if they delivered it with batteries that were marginal at best.

Steve K
Oh, if that's the case then that seems to be the culprit...
2013 31' Silver Twin Bed
Semi-retired 6/21....
Re: My AGM's are not holding a charge
Reply #11 –
Hi Ted;  Your batteries may be almost ok.  Through experience with my wet lead acid batteries, they stratify and develop a surface sulphate barrier layer due to being fully charged and just sitting there. I'd go to Morro Bay, and watch the battery voltage drop through use. Minimal charge throughout the day. At night I would use the heater.  My old TK has a small fan, about 3 amps to run it, about 1 1/2 incandescent light fixtures worth, and (not on continually).  [how do you heat a bigger motorhome with the same size space to put the heater? Bigger burner and bigger fan!]  I would watch the voltage and during the night the resting voltage would increase! After a few days of this the batteries would break through the sulphate layer and start working as designed, with not as much voltage droop, and better peak current response, water pump speed with lights on, etc.
    Your converter and solar both can do equalization, which is designed to destratify the electrolyte, and prevent sulphation, but the AGM batteries would be damaged. I think that letting them 'droop', then charging with the engine alternator will help restore them. The engine alternator is more 'brute force'. Just a 3 phase sine wave with full wave rectification, the pulsating DC will be good for the somnolent batteries.
    A side note: I had an Interstate starting battery that should have lasted longer, in the trunk of my car as I went to Costco to have a tire sender replaced (12 years old), and they couldn't start the car. Called AAA and they determined the Interstate battery was bad, less than a year old, bought at Costco. They replaced that one, no charge, and the one in the trunk for a minimal fee. The store person said that they had a lot of batteries failing lately.  I researched Interstate, and they market and advertise, but have contracts  with other makers Exide, Johnson and others. So they don't actually make batteries.
    Like Larry I'm waiting to see what shakes out in the LiFePO4 arena.        RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: My AGM's are not holding a charge
Reply #12 –
I agree if the unit was a demo batteries seem to be bad.  Also, if you have two batteries one may be bad.  One may be good.

Here is a statement from Trojan users manual:
* If any recorded voltage differs from another one by more than 0.3V, compared to any
other battery in the set, you may have a failed battery.

So you would have to isolate both batteries from everything by disconnecting the cables.  If batteries are charged then measure the voltage after every say 15 minutes.  See if one or both batteries voltage differs by 0.3V between readings. If you find one is bad you can just connect the good one (if they are 12 volt!) and have use of things until you can get them replaced.

Link to manual.
https://www.trojanbattery.com/pdf/TrojanBattery_UsersGuide.pdf

Ron

Snap a picture of cables BEFORE disconnecting them.  Makes it easier later.
Ron and Linda
Ada Michigan
Re: My AGM's are not holding a charge
Reply #14 –
Quote from: tedeboy  - 
With my previous LD I didn't have solar.  I could use the heater and other items for at least 3 days with my Trojan  T-105+ batteries before needing a charge.

I pulled into the shaded campsite fully charged. Within 24 hours the fridge was shutting off. I checked the volts and it was alarmingly 10.5. I took a meter outside across the terminals to confirm and it was 10.5 as shown on my solar controller.

Ted, as your no rookie here, your old MH was much like ours. My thought comes to, do you have some kind of inverter that might be drawing the battery's down in the new motor home that you didn't have in the old one. Or pull the center positive to negative lead off the battery and read your voltage on each battery and see if they each read 6 volts when charged. The one that doesn't read 6v may have a dead cell.

Jon
1994 MB
Re: My AGM's are not holding a charge
Reply #15 –
Quote from: Sarz272000  - 
If you find one is bad you can just connect the good one (if they are 12 volt!) and have use of things until you can get them replaced.
The batteries are 6 volt wired in series.

Charles
Harvest Hosts + Boondockers Welcome #23975
Escapees SKP #138195
2007 23.5' Twin King
Re: My AGM's are not holding a charge
Reply #16 –
Had the same problem... batteries not holding charge.

Turned out to be loose connection at chassis ground on the frame. Once it was tightened, no more problem!   ::)
Steve S.
Lazy Bones & Cedar
2004 30'IB (Island Bed)
Yesterday is History, Tomorrow is a Mystery
Live for the day!
Re: My AGM's are not holding a charge
Reply #17 –
UPDATE

Lifeline is sending 2 new batteries to a Coos Bay battery place where I'll have them installed.
Good customer service.
2021 Mid Bath
Re: My AGM's are not holding a charge
Reply #18 –
Quote from: JonS  - 
Ted, as your no rookie here, your old MH was much like ours. My thought comes to, do you have some kind of inverter that might be drawing the battery's down in the new motor home that you didn't have in the old one. Or pull the center positive to negative lead off the battery and read your voltage on each battery and see if they each read 6 volts when charged. The one that doesn't read 6v may have a dead cell.

Jon

No inverter.  All stock.
2021 Mid Bath
Re: My AGM's are not holding a charge
Reply #19 –
Quote from: Lazy Bones  - 
Had the same problem... batteries not holding charge.

Turned out to be loose connection at chassis ground on the frame. Once it was tightened, no more problem!   ::)

The chassis battery ground on the MB is located where? I'd like to check it.

 Anyone know?
I'll crawl around and take a look.
Thanks
2021 Mid Bath
Re: My AGM's are not holding a charge
Reply #20 –
Hi Ted,

The chassis ground on our RB was near the battery box. Followed the conduit to the frame.

Kent
2015 27' RB "MissB.Haven"
Re: My AGM's are not holding a charge
Reply #23 –
Without doing a lot of checking, tightening and testing, while using a multimeter, you can't know for sure if the batteries are bad, new ones may not cure the situation. Since the AGMs are being replaced under warranty, that's great but you may find the problem still exists.
I do agree that if this was an LD floor model, the batteries could have been fried while at the Mothership, AGMs are very sensitive creatures and are not a robust as the older Trojan lead-acid batteries.

In the meantime, I would check and tighten every accessable connection, check the circuit breakers, including the "hidden" breaker, now I believe it's located in the battery compartment on the back wall.
Once you have installed a battery monitor, you will be able to watch the charging and discharging currents to get a better idea of what is occuring in the charging system andif there are loads you are not aware of. They are handy devices.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: My AGM's are not holding a charge
Reply #24 –
Quote from: Larry W  - 
....
I do agree that if this was an LD floor model, the batteries could have been fried while at the Mothership, AGMs are very sensitive creatures and are not a robust as the older Trojan lead-acid batteries.

....

Larry

I'm going to assume a few things.

This is a demo showroom model built in January 2020.
The covid shutdown closed the showroom.
If this coach wasn't plugged in or in direct sun then these AGM's might be toast. We'll know soon.  I'm getting knew ones installed next week and I'll have the old ones tested.

I've checked the connections and circuit breakers. All good.
2021 Mid Bath