Batteries not holding a charge

[Blueswede]

We have a 2021 Cougar 368MBI....bought it new and have had no problems since day 1. We're at a campsite with no hook ups. I have a generator for AC, etc. Since we got here I'm seeing that the batteries are not holding a charge. I do have solar which has performed perfectly since we got it. When I have the generator running the little solar box/screen in the compartment shows 13 volts and that it is charging. Not long after shutting off the generator the voltage will drop to 9-10 and I'll get a low battery warning screen. What might be the issue? Any assistance is greatly appreciated.

[Carl n Susan]

The battery disconnect is the most likely cause.

[Blueswede]

So what would be the fix for that?

[Carl n Susan]

Assuming you have a battery disconnect switch (perhaps in the convenience center?) ensure it isn't in the position where the batteries are disconnected.

A Volt Ohm Meter (VOM) will help find where the 12V charging issue resides. Obviously the battery is badly discharged. You need to find where the 13.5V volts from the converter and/or solar are stopped from reaching the battery.

[Hblick48]

Once a lead acid battery has gone lower than 12 volts, it's slightly better than a paper weight. No longer able to hold a charge.

[Blueswede]

These are AGM batteries...

[RollaMo]

Originally Posted by Blueswede

These are AGM batteries...

AGM batteries are still "Lead Acid".

Only difference is instead of "wet", they are constructed with "Absorbed Glass Mat".

[Carl n Susan]

The status of the batteries really isn't the issue here. The OP has 13+V while plugged in and 9-10 when not. The 13+Vs are not making it to the battery. Use a VOM to find how far the 13+Vs goes. I bet it doesn't get to the battery cable ends.

Once that issue is figured out, start figuring out why the solar isn't charging the batteries.

[Blueswede]

So it ended up being a pretty simple problem...my batteries just weren't holding a charge. I took a drive to a nearby town and picked up 2 new Die Hard batteries, switched them out and everything is back to normal. Thanks to all who offered some advice. I'm very grateful that it was a simple solution.
I have no idea how old the original ones were....the little date stickers were never removed. Just wondering how many years you all are getting from your batteries....thanks in advance.

[flybouy]

Battery life will depend on battery type (in group size, deep cycle vs combo or starting battery, Amp hour rating, etc.). Also, how the battery is used and how it's maintained. For example, if you have grp 24 "deepcycle/starting " batteries that most dealers supply and the batteries have been drained to 12v or less they will not last very long. A pair of gc 6v batteries wired in series, not discharged below 6v and the acid level maintained could easily last 4 years or much longer.

Unfortunately there's just too many variables to offer any definitive answer.

[Hblick48]

Originally Posted by Blueswede

Just wondering how many years you all are getting from your batteries....thanks in advance.

I had four 6 volt golf cart batteries. 2 were dated 2017 and 2 were 2018. I purchased all new and they never went under 6 volts and never ran low on water. I live in Northern California, so no cold winters, but hot summers.

About 2 months ago, they finally didn't hold a charge well, drained much faster than new. They lasted way longer than I would have thought.

I replaced with 280 amp LiFePO4, new charge controller and added 200 watts of solar (total now 500). Going on our first boondock trip in a few weeks. Can't wait to test new setup.

[JRTJH]

Originally Posted by Blueswede

.... Just wondering how many years you all are getting from your batteries....thanks in advance.

Our first battery in the Springdale was a Exxide GP24 RV/Marine hybrid (deep cycle/starting battery). It was discharged to 40% several times the first year, left on the trailer over the winter (6 months in northern Michigan) and would not hold a charge the second season when we pulled the trailer out of storage.

Our first battery set (2 GC2 deep cycle 6 volt golf cart batteries) were installed in the Cougar in 2013 before the trailer was delivered to us. They were removed before storage and stored in the garage (about 50F most of the time) and recharged monthly during storage. They were never discharged below about 50% when camping. They lasted from 2013 until 2021 when Sam's Club had a 35% off sale on golf cart batteries. I replaced them early, even though they were still functioning well. The plan had been to replace them in 2022 or 2023 anyway. I kept the batteries and turned in two old "car batteries instead". My BIL is still using my original GC2's in his trailer and he says they're still working good.

So, battery type, battery size, use (how they are maintained and discharged before recharging) are so variable that it's "nearly impossible" to determine how long a battery will last.

Properly cared for, never discharged below recommendations and stored properly during the off season have as much or more influence on how long a battery will last. I'd guess just as much influence as which brand or where you buy them....

[Phil Saran]

On our 2019 Keystone Cougar 30RLS (purchased 10/18) I replaced the one Group 24 battery with two Group 27 batteries from Costco in mid 2019.

June 2024 I found one had a dead cell so I replaced both again with Group 27 batteries from Costco.

So I got 5 years use of them.

We sold the RV about 3 weeks ago.

[lcarver02]

Originally Posted by Blueswede

We have a 2021 Cougar 368MBI....bought it new and have had no problems since day 1. We're at a campsite with no hook ups. I have a generator for AC, etc. Since we got here I'm seeing that the batteries are not holding a charge. I do have solar which has performed perfectly since we got it. When I have the generator running the little solar box/screen in the compartment shows 13 volts and that it is charging. Not long after shutting off the generator the voltage will drop to 9-10 and I'll get a low battery warning screen. What might be the issue? Any assistance is greatly appreciated.

Your batteries are likely sulfated and need to be replaced. Be sure to get the right type of battery for the job, improved capabilities are always good to get. You could use a good battery charger to disulfate the batteries, I have never had success with those. I do put my batteries in for the winter and disulfate them for a few hours and put a trickle charge on them all winter.. Most batteries used by Keystone last 3 years and they are done. Not sure if you use 6v or 12v wiring, assume 12v by your charge statement of 13v. You can also charge batteries full and do a load test. Should hold above 9.6v

[NH_Bulldog]

Originally Posted by lcarver02

Most batteries used by Keystone last 3 years and they are done.

Just to clarify, Keystone doesn't provide batteries, it is the dealer that adds them. So what comes with a trailer is whatever the dealer puts in there unless you specify a certain one. (The brief exception was last year when Keystone shipped a number of units direct from the factory with Dragonfly Heated LiFePO4 batteries installed, but they didn't do it very long for whatever reason.)

When I bought my Passport in 2019 the dealer installed two Interstate Group 27 RV/Marine batteries (I didn't even have to ask). I would pull them out in the fall and keep them on a tender inside the shop all winter, then reinstall them in the spring. We sold the Passport this spring when we bought our Cougar and I had the batteries load tested for the buyer and they were still as strong as ever after five full camping seasons.

Anyway, a quality battery that is taken care of and not abused or overly discharged will provide many years of trouble free service.

[rhayden66]

My neighbor had a similar problem. We are in a full-service park, then there was a power outage. We were sitting outside, and my lights flickered when the power went out, but the intensity of the lights never changed, while their lights faded and then went out. I check the battery and find the cell were out of water and the plates were exposed. Swapped out the battery for a full charged all was good. I serviced the old battery and gave it a hard charge for a couple of hours, then a slow charge overnight. We are still using this battery as a backup. I suggest you have your battery checked for correct level of acid and water, by a technician.