Battery overcharge signal

[tommyro]

2005 ram 2500 5.7L 4x4 started ******* out battery gauge on high side with 'check gauges' light. Only seems to happen when stopped at light for 20 sec or more. Gauge stays in middle with normal acceleration/ driving, but starts to creep up, then pegs out at long stops. Once pegged out, it stays there until shut down. I shut everything down and then re-start, and gauge is at normal, until next stop light. Truck seems to start and run normally. Dash and outside lights flicker at times. Cables and connections are clean and tight as far as I can tell.
I assumed bad alternator. New reman unit with same specs installed- no change. I always shut it off within a few seconds so as to avoid damage to battery or other elec components. I have read about the possibility of a bad instrument cluster sending a false signal, but would that cause the flickering lights?
Put multimeter on resting battery. 5 hrs since last running. It showed only 12.10v. Shouldn't it be 12.4-12.5V?
I want to check battery when in 'overcharge', but of course I can't get it to happen in the driveway...
Need Help!

 

[crash68]

They make car phone chargers that have battery voltmeter read outs on them fairly cheap. Charging voltage while the truck is running should be roughly 13.8-14.4 volts
It's possible your battery is in the early stages of one of the cells failing causing the sporadic over voltage issue?

 

[Johnsram]

As stated above at 12.1 v your battery is nearly dead and requires replacement...unless your alternator is not charging it. But then the low voltage would be constant.

 

[tommyro]

Checked battery this morning, (sat overnight)- 12.2v. Ran for 8-10 min in P, gauge stayed middle, batt tested 14.4v - 14.5v the whole time. Truck sat for about 4 hrs today- down to 12.2 again.
Talked to a reputable battery dealer who said that yes, my battery is going bad, but doesn't think it's causing the occasional overcharge problem. He suggested a bad alternator, (second one?) or poss a bad sensor or wire or connection somewhere else. He is sure that the problem would be consistent if it is the battery causing the overcharge. And no, he did not sell me the current battery.
It is strange that it only seems to happen while actually stopped during driving.
I'm ready to pull my hair out over this one. People are looking at me funny every time I turn engine off, then on at stops.
I'm tempted to get a new battery since everyone agrees that it will soon be needed, but I'm not too keen on the idea of getting a new battery knowing that some outside overcharge issue could cause an early death for the new battery...

 

[chopperman1]

Why guess? Go to your local autozone and have them test the system

 

[tommyro]

Because I haven’t been able to replicate the issue when needed, I doubt they would find anything more than I have already. The gremlin does not make itself known under test conditions, so far.

 

[Ramnewbie]

Go get a new battery, you'll have 2/3 year free replacement if something happens that messes it up.

Sent from my XT1650 using Tapatalk

 

[Ramnewbie]

You're battery is basically a shock absorber or catch all for anything extra the alternator puts out, minus what you need to run the truck plus accessories. As simple as a battery is it can screw up alot of things. You can get a load test on the battery and check alternator at same time at any advance auto store.

Sent from my XT1650 using Tapatalk

 

[tommyro]

Drove around town today for 1/2 hour, trying to get it to do what it did at every stop light a few days ago- didn't happen. No run-up on the gauge, no warning light, no flickering of dash or outer lights.
Stopped at advance auto to have them test. The battery tested slightly low, as expected, and the alternator was in normal limits.
Going to drive around with multimeter in truck, hoping to come across overcharge mode and check battery then and there.

 

[tommyro]

Drove across town yesterday with my trailer. Overcharge signal shown several times. On 2 of them, I pulled over, kept truck running and checked battery. With gauge buried on o-charge side, I got 14.6v and later 14.45v, which I believe are normal. So, what is the reason for the signal if I conclude that there is no actual o-charge occurring?