190 Popular chassis battery issue

[BBURG190]

The chassis battery in our 190 Popular will charge up to 12.5 to 12.6 volts when driving. After 1 to 2 days the voltage will drop to approx. 12.0 volts. A GM dealer has said the alternator is OK, and they did not find a parasitic current drain. An Autozone dealer tested the battery after it had been fully charged, and said it was a good battery. Any suggestions at this point would be most welcome.

[phantomjock]

These are the questions I would try and answer:

1. Age of the battery?
2. Vehicle stored outside - what is the temperature drop?
3. Are the voltage measurements at the battery - or on the dash?

Then, I'd get a full charge - (external charger), on the battery disconneted from the chassis. Check it after a few days and see what you have. Is this what Autozone did? Or, did they put a quick charge on it and then do a load test to declare it "good"?

How long did the dealership have it to declare no parasitic current drain? Testing it out of the vehicle (or disconnected) will be a sure test of the battery.

I'm no EE, but those are the things I'd check.

Electrical systems can be confussing, best of luck. Oh yeah, Happy New Year!

Cheers - Jim

[TomF]

First, a few questions. What type of battery? Voltage reading from multimeter, or voltmeter on vehicle? 12.0 V reading at rest with no load?
Personally, I don't trust the quick test they do at the store. I had a known bad battery that checked ok with one of those devices. Sounds like a bad battery to me.

[BBURG190]

Battery is a one year old lead-acid Diehard Gold. Voltage was measured with multimeter across battery terminals with battery still in vehicle. Voltage was read after DC clamp on ammeter read essentially zero amps, indicating vehicle had "gone to sleep." Battery tester appeared to be the electronic kind, which does not actually "load" the battery; voltage was still at 12.6 volts after the test.

[tarp]

Make sure someone looks at how the bolts on the battery are seating.

[booster]

It is always very helpful for questions like this to give the year and model of the RV, how many amp hours of batteries, what type of batteries, what charger is used in the coach, if alternator is also charging, etc.


Everything has changed so much over the years, plus many older vans have been upgraded, it is nearly impossible to give much useful information about what an issue might be.

[BBURG190]

We have a 2008 Roadtrek 190 Popular. We have an 800 Ah lead-acid chassis battery. The charging system is the stock Roadtrek system from 2008.

[phantomjock]

I'll restart/restate; you have problems with the Chassis Battery (the one under the hood) - correct?
Also, you say it is 800aH lead acid battery- but I suspect that might be 800CCA (Cold Cranking Amps). An 800aH Lead Acid would be quite large. I believe this is what you are referring to:

DieHard Gold Battery: 78 Group Size, 800 CCA.

Were it my RT, I'd charge the battery, disconnect it, the measure the voltage after disconnecting, then after a few days of being disconnected. That could tell you something about;

the state of the battery,
the charging system (alternator), and
any leaks.

[My preference would be take it out of the van and charge and test on the bench, determine its health. Then re-install and repeat the tests.]

I like the suggestion tarp made about how the bolts are seating on the battery. Side posts can be a problem, especially if someone has over tightened a long bolt and broken the internal connection - so I understand. A bad internal connection would lead to a number of problems. As can Bad Grounds. But I wouldn't go to that just yet.

You have suggested the "...charging system is stock Roadtrek system from 2008." Any extra leads coming off the battery? Radio, Underhood light, GPS, etc? Charging is one half of battery use, and discharging (the other) seems to be your problem right now.

Good luck!

Cheers - Jim

[BBURG190]

Thanks for your comments, Jim. You are correct; it is 800 CCA, not 800 Ah. There are no additional leads coming off the battery. I believe your idea of monitoring the disconnected battery is the best way to distinguish between a bad battery vs. a parasitic drain. I have just re-installed the battery after having been trickle charged to a full 12.6 volts. I am going to monitor it for several days and see what happens.

[topwop]

I have a 2006C210P and have heard many folks complain about the Chevy radio that stays on after you turn the vehicle off and if you don't exit out the drivers door it can still draw on the battery. Could this be what's happening to yours? Fortunately for me I had the original radio replaced and told the guy who did it to disconnect that option when he installed it alleviating the problem all together.

[Lanex005]

Our 2002 Rt popular 190 did that. We even replaced the battery and another connection part( I’m blanking on the name) BUT it turned out that the ground from the battery was corroded. We got a new ground wire cleaned up the area it connected to the chassis and our battery stayed charged!!!

[BBURG190]

Our 190 Popular does not have the original radio. I have tried to make sure everything is turned off when exiting from the driver's door, but have not observed any beneficial change in battery state of charge.

[BBURG190]

The mechanic I trust used a conductance tester and verified the alternator is properly charging the battery. This would lead me to believe the ground connection is good, but I will verify this with a multimeter.

[peteco]

A battery can show ~12.6v after charging yet still be bad. A load test is necessary to prove the health of the battery. Most auto stores will do a free load test.

On my 2006 Chevy Roadtrek the radio occasionally does not switch off when I open the door. I make it a habit to check the radio when I exit the vehicle. If the radio doesn’t turn off, I close the door, wait a few seconds, then open the door again. It usually shuts off then. If not I wait several seconds longer and repeat.