Has my battery gone Toes Up?

Ken & Peggy

Ken & Peggy

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We just spent several days in New River Gorge NP (an awesome place btw) and the battery performed badly. We have the CF35 Dometic that will usually do just fine for a few days. Not this time. We wound up buying ice for our last day. I tried running the TV for about 30 minutes to give it a bit of charge which helped a bit.

After driving the 500+ miles home yesterday the voltage read 11.1

On a landline it's still taking 13.5v, so I'll let it go.

It's not that old, I will have to check my records. Unfortunately I do think it's a goner...

Thoughts?
 
It would be roughly from August/September 2017. That was when I upgraded to the bigger battery. So it's not quite 6 years old.
 
Ken & Peggy said:
We just spent several days in New River Gorge NP (an awesome place btw) and the battery performed badly. We have the CF35 Dometic that will usually do just fine for a few days. Not this time. We wound up buying ice for our last day. I tried running the TV for about 30 minutes to give it a bit of charge which helped a bit.

After driving the 500+ miles home yesterday the voltage read 11.1

On a landline it's still taking 13.5v, so I'll let it go.

It's not that old, I will have to check my records. Unfortunately I do think it's a goner...

Thoughts?
Click to expand...


You could try defulfating it --- The onboard charger doesnt' seem to do a great job, but the CTEK seemed to do better. My battery (I _Flat_ emptied it 2 or 3 times now) is damaged. This spring, I was testing a 220 watt solar panel I purchased, and I found the CTEK actually improved the batteries life by a noticeable mount...

Hopefully you're 5 days inside the warranty period and get a free replacement --- I don't know if Walmart is pro-rated or not...
 
It's been on the charger since yesterday about 6:30p, and is holding at 13.1 volts when unplugged.
I talked with Craig, and his thought was that maybe the charging contact wasn't making up at the 7 pin plug on the ride home. I tried connecting the TV to the trailer and got good lights on the CTEK, with the voltmeter going to 14.7. So my TV to trailer wiring is good.

I'm going to grab a load tester next to see if that gives me a definitive answer to this vexing issue.
 
Sweeney said:
You could try defulfating it --- The onboard charger doesnt' seem to do a great job, but the CTEK seemed to do better. My battery (I _Flat_ emptied it 2 or 3 times now) is damaged. This spring, I was testing a 220 watt solar panel I purchased, and I found the CTEK actually improved the batteries life by a noticeable mount...

Hopefully you're 5 days inside the warranty period and get a free replacement --- I don't know if Walmart is pro-rated or not...
Click to expand...
If the load test is iffy, I will probably try to desulfate. Great idea, thanks.
 
Ken,

6 years is a lot to get out of the AGM when using the fridge. I am guessing the battery is coming to end of life. The fridge is the big factor here, it increases the depth of charge/use cycle which adds a more substantial count to the cycle life of the battery. I see lots of fridge users get only 3.5-4.5 years out their batteries.

Load test for sure is the next logical step.

Cary
 
Cary Winch said:
Ken,

6 years is a lot to get out of the AGM when using the fridge. I am guessing the battery is coming to end of life. The fridge is the big factor here, it increases the depth of charge/use cycle which adds a more substantial count to the cycle life of the battery. I see lots of fridge users get only 3.5-4.5 years out their batteries.

Load test for sure is the next logical step.

Cary
Click to expand...
Thanks Cary. I should be able to get that done today.
Assuming it's time to replace, what's the current battery universe look like?
 
OK, I just load tested the battery (one 10 second draw) that immediately took the voltage from 13.0 to 12.5. After the test the voltage came to 12.7 almost immediately and then to 12.9 within another minute or so.
I'd say the battery is OK, yes?

Anything else to do/check before I close?
 
Ken & Peggy said:
OK, I just load tested the battery (one 10 second draw) that immediately took the voltage from 13.0 to 12.5. After the test the voltage came to 12.7 almost immediately and then to 12.9 within another minute or so.
I'd say the battery is OK, yes?

Anything else to do/check before I close?
Click to expand...

You'll get absolute and concrete results using a battery test meter. Something like this - a volt meter alone isn't beneficial here. You can still get 12 volts on a battery which is 'unhealthy'. If you don't have a test meter (and don't want to buy one) most car parts and battery shops will test the batteries for free hoping to sell you a new battery if you need it.

If you want to geek out a little on battery health, this video gives an excellent 6-minute lesson on the true culprit...internal resistance.
 
Sweeney said:
You'll get absolute and concrete results using a battery test meter. Something like this - a volt meter alone isn't beneficial here. You can still get 12 volts on a battery which is 'unhealthy'. If you don't have a test meter (and don't want to buy one) most car parts and battery shops will test the batteries for free hoping to sell you a new battery if you need it.

If you want to geek out a little on battery health, this video gives an excellent 6-minute lesson on the true culprit...internal resistance.
Click to expand...
That's what I did. I used a load tester - a Schumacher BT-100 Battery Load Tester.

I'm still at a loss as to why, after driving 500+ miles the trailer battery showed at 11.1 volts. Craig's thought was that maybe my charge pin wasn't making up correctly. Possible, but that seems unlikely since the rest of my lights worked. The Dometic was running, but that shouldn't be a problem for a good battery. Which this battery should be since I load tested it to find out!

I'll know for sure on our next trip. I'll be sure to get a sunny campsite of possible to be able to use the solar panel.
 
Ken & Peggy said:
That's what I did. I used a load tester - a Schumacher BT-100 Battery Load Tester.

I'm still at a loss as to why, after driving 500+ miles the trailer battery showed at 11.1 volts. Craig's thought was that maybe my charge pin wasn't making up correctly. Possible, but that seems unlikely since the rest of my lights worked. The Dometic was running, but that shouldn't be a problem for a good battery. Which this battery should be since I load tested it to find out!

I'll know for sure on our next trip. I'll be sure to get a sunny campsite of possible to be able to use the solar panel.
Click to expand...

EDIT: I identified the wrong pinout originally --- Updated to hide my shame :)

If the battery tests OK, then the charge pin is your next logical only choice. If you start the car, you should see 13.8+ volts coming off the alternator....what battery isolated are you using? Mine is the ctek 205...it takes a few minutes to realize the voltage is high enough to charge before it starts...but you should see charge voltage (13.8+) on the battery shortly after the car starts...if you aren't seeing an charging voltage then the charge pin is the logical choice.

You can check this with a volt meter; just look for 12 volt+ on the on the tow vehicle side of harness on the charging pin. (EDIT: See @SethB update below for details on which pin that is). If you have to charge voltage there, check for voltage at the battery isolator...in my case the CTEK 205....which isolator do you have in yours?
 
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Sweeney said:
If the battery tests OK, then the charge pin is your next logical only choice. If you start the car, you should see 13.8+ volts coming off the alternator....what battery isolated are you using? Mine is the ctek 205...it takes a few minutes to realize the voltage is high enough to charge before it starts...but you should see charge voltage (13.8+) on the battery shortly after the car starts...if you aren't seeing an charging voltage then the charge pin is the logical choice.

You can check this with a volt meter, just look fro 12 volt+ on the center pin on the tow vehicle. If you have charging voltage there, check for voltage at the battery isolator...in my case the CTEK 205....which isolator do you have in yours?
Click to expand...
Great test procedure Sweeney, but I think that’s the wrong diagram in the attached image. The 6 pins are a dead giveaway! I think that on the TV side one finds +12v upper right on Pin 4, and ground lower left on Pin 1.
View attachment upload_2023-5-25_7-52-9.png
 
Lipster said:
How old is it?
Click to expand...
I can't speak to yours but I don't think I ever got even 5 years on a battery using the fridge. Got tired of replacing them every few years and got a Renogy Li battery that I'm delighted with. Now I run the fridge directly from that and never plug it into the trailer. I also added their 40 amp DC-DC charger to my vehicle and use that to keep the Li battery charged as necessary if solar is insufficient, which is not often. It gives me much longer life for the fridge than the AGM and I don't have the problem of the fridge cycling off when the fridge load cycles on, momentarily dropping the voltage after the battery has been depleted some over a weekend.
 
I've got the CTEK D250SA. All lights indicate everything is wired properly and working as it should. I think I may have expected the battery to perform better than it could under the circumstances we put it in.
We'll see how it does next trip.
I may wind up looking at a separate battery for the Dometic in the TV at some point if needed...
 
Ken & Peggy said:
I've got the CTEK D250SA. All lights indicate everything is wired properly and working as it should. I think I may have expected the battery to perform better than it could under the circumstances we put it in.
We'll see how it does next trip.
I may wind up looking at a separate battery for the Dometic in the TV at some point if needed...
Click to expand...

Not going to lie, I think having a separate LiFe battery with a display showing state of charge that you can discharge to 0% makes using the Dometic way less stressful.
 
Ken & Peggy said:
I've got the CTEK D250SA. All lights indicate everything is wired properly and working as it should. I think I may have expected the battery to perform better than it could under the circumstances we put it in.
We'll see how it does next trip.
I may wind up looking at a separate battery for the Dometic in the TV at some point if needed...
Click to expand...

The CTEK has a great setup. Using the 220watt solar (18volt @ 220 amps) I get a really fast charge and after letting it charge a couple days, my battery health improved. According to the manual, desulphation is the first 4 hours of the charge cycle. So you are probably just fine in that department.

Good luck -- I've always stuck with the cheap lead acid batteries. $95 at walamrt. Friday night through Sunday been fine as long as I am careful about not charge too many laptops ;)

The CF35 and the new CFF35 both seem to be similar in that department. Keeping it out of the sun helps.
 
This thread got me curious. I have flatlined my batter three times now. I'm talking so low a light wouldn't even glow.

I decided to test my battery. Thanks to amazon points, I bought a tester and emptied the storage bin. The 1 1/2 year old battery that has been abused tested out perfectly healthy. Perhaps the deep-cycle batteries are more resistant than I have assumed.
 
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