Battery goes to “low” while operating slides

Rabbit

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I have a newish 12V AGM battery. I keep the battery on a maintenance charger in the garage between all trips (dismounted from the trailer). On recent trips the battery readout on the control panel goes to “low” when operating the slides. It starts showing fully charged, then drops slowly, and the trailer is connected to shore power at the time. I took it to Advanced Auto and had them put it on their tester, which showed the battery if okay.
Comments (constructive, please) appreciated.
 
What group size is the battery, also amp hrs ?
Slides take a lot of juice, it sounds like the battery doesn't have enough capacity.
 
I have 23 gd imagine 2600rb. When doing slide battery drops on panel (not on shore or to truck). Once in or out, battery goes back to full charge. Solar charger does great.

Considering going to lithium. Starting planning that out for spring.
 
I have a newish 12V AGM battery. I keep the battery on a maintenance charger in the garage between all trips (dismounted from the trailer). On recent trips the battery readout on the control panel goes to “low” when operating the slides. It starts showing fully charged, then drops slowly, and the trailer is connected to shore power at the time. I took it to Advanced Auto and had them put it on their tester, which showed the battery if okay.
Comments (constructive, please) appreciated.
Using the slides pulls a lot of current from the battery. So no surprise that it dips when running the slides.

When you dismount if from the trailer are you keeping a battery charger/maintainer on it? You should.

As for fully charging and then dropping slowly - that sounds odd. Especially if the rig is connected to shore power. On shore power the converter should provide a health 12 volts to the rig as well as charge the battery; more like 13.5 volts. Then once bulk charged the voltage should drop some. You should monitor the battery when connected to shore power with a volt meter to see that it is getting a bulk charge to start with and then a float charge that says pretty steady. If not then check all connections and consider that the battery may be marginal.

Is this something new or has it always been like this?
 
I have 23 gd imagine 2600rb. When doing slide battery drops on panel (not on shore or to truck). Once in or out, battery goes back to full charge. Solar charger does great.

Considering going to lithium. Starting planning that out for spring.
Sounds like my situation, except I don’t have solar. Just seems odd to me to have the panel show battery at lowest indication after starting out at max and only bringing in two slides.
 
Using the slides pulls a lot of current from the battery. So no surprise that it dips when running the slides.

When you dismount if from the trailer are you keeping a battery charger/maintainer on it? You should.

As for fully charging and then dropping slowly - that sounds odd. Especially if the rig is connected to shore power. On shore power the converter should provide a health 12 volts to the rig as well as charge the battery; more like 13.5 volts. Then once bulk charged the voltage should drop some. You should monitor the battery when connected to shore power with a volt meter to see that it is getting a bulk charge to start with and then a float charge that says pretty steady. If not then check all connections and consider that the battery may be marginal.

Is this something new or has it always been like this?
Appreciate the suggestion to monitor the battery while installed on the trailer. I’ll do that next trip.

I do remove the battery when the trailer is idle and in storage. It’s kept on a quality charger with a maintenance stage at all time the battery is dismounted. It has always dropped some, but not to the lowest indicator on the panel. That’s why I took it to be checked on a load tester. But I confess I don’t trust their verdict. That’s why I’m asking here.
 
Appreciate the suggestion to monitor the battery while installed on the trailer. I’ll do that next trip.

I do remove the battery when the trailer is idle and in storage. It’s kept on a quality charger with a maintenance stage at all time the battery is dismounted. It has always dropped some, but not to the lowest indicator on the panel. That’s why I took it to be checked on a load tester. But I confess I don’t trust their verdict. That’s why I’m asking here.
If you replace it consider a larger ah battery. Or maybe 2 6 volt AGMs in series if you can.

Still sounds like a bad cell in the battery. Maybe take it to another place for another test.
 
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If the battery's are removed take them to some one (NAPA) and get them load tested. That will tell you the condition of them. Have them fully charged before. Make sure someone that does it understands the process.
 
If you repl e it consider a larger ah battery. Or maybe 2 6 volt AGMs in series if you can.

Still sounds like a bad cell in the battery. Maybe take it to another place for another test.
I agree. It’s still under warranty so am inclined to exchange it.
 
Are you sure that the battery cutoff switch is turned on? With it on shore power, the converter is powering the 12v system, and can even do so without any battery at all. BUT, it is not a heavy duty supplier of amps, so without an assist from the battery, that may be what is causing the power sag when running the slides.
Unplug from shore power, so it is only the battery running the system, and see how it behaves - not at all, the same, better, or worse? If the same or worse, then yes it is the battery at fault.
 
Perform a voltage drop test.

Assuming that the battery is good, the only way for the battery voltage to drop that much is the slide motors are worn/shorted, the slides are dragging, or the wiring is compromised. Being that it's an RV, I would start with the wiring.
 
When charging the battery outside the trailer, make sure the battery is on a block of wood. If on concrete it will drain from the battery.
 
When charging the battery outside the trailer, make sure the battery is on a block of wood. If on concrete it will drain from the battery.
This is why you can't trust everything you read on the internet.

 
Not really, those of us that remember when batteries were made with wood, but I suspect that is nobody here.

But it is funny that I heard this 45 years ago and it was as real as it is now.
 
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