Your battery voltage - truck off and at rest

[ShadowsPapa]

Interesting. So it's only charging above 15?

It seems strange because the battery says to not charge it over 14.4, but maybe the dash readout is not really the best way to verify that...

Was that the dealer you brought it to? When I brought mine in they told me the only way to get it warrentied was to have the computer test it and issue the work order and that the test took nearly 6 hours. If they didn't run it though the computer and just replaced it (even if obviously bad), FCA would not pay them.

Maybe different if you are not under warranty?

Where did you get the 15 volts?
It's obviously charging a bit, otherwise after a few days it would be dead or at least under 11 volts and not start the truck. It's not fully charging the batteries. These never run over about 14.7 - or shouldn't.

What battery says not to charge over 14.4? These? I've not seen that but then I've not pulled the batteries out - and - different AGM batteries specify different charging voltages for the various phases. Optima for example specs higher voltages than some of the others.

Not sure what you are talking about having a computer test it and taking 6 hours. Can't think of anything that would do that. They can certainly replace batteries without and hours long test. They absolutely can get reimbursed for replacing a battery that fails a load test. They do it all the time.
Can't figure out what you are talking about there.
Maybe the GR8 test? That requires a battery have a OCV of 12.4 before testing and charging it to that point may take time. In my case it took 38 minutes to get to 12.4 before the GR8 test could be done.

Sponsored

 

[ShadowsPapa]

Reading through all of this and it’s become clear i know less about my truck than I thought I did.

My own ignorance reminded me of a fantastic counseling bullet point i read years ago. “Soldier has found rock bottom and shows signs of starting to dig”

while pulling my camper home today to de winterize it i had my curt echo up. When the truck shut off the echo app would flash “low battery” ive never seen that before. With the truck off at the stop light the battery read 12.2-12.4 on the dash. It popped back up to 14.5-14.7 quickly once the truck started back up.

am I starting to see a issue or am I connecting dots that aren’t there?

the jt is nearly 3 years old and has 63,000 miles on it. So im sure im probably due for a new battery soon anyway.

The 14.x volts is the voltage from the alternator - I know it says "battery voltage" but that's not technically true. It's what I personally call "system voltage" as that's what it in the electrical system at that time. The 12.x is the actual battery voltage. 12.2 is low, to even test these they have to be 12.4 volts - and that meant they had to charge mine before they could even test it. I would think DUH would apply in my case, I mean geesh, I take a truck in with a battery voltage of well under 12.4 and they had to charge it before they could even test it - doesn't that suggest there's something not keeping up? I would not have taken it in if the battery voltage had been 12.6 for example. Maybe the batteries are ok - maybe that's true, but for some reason they aren't getting charged and staying up. The IBS senses the DRAIN on batteries as well.......... so......... next time that stops working and the battery state is down again, I'm taking it to the dealer across the county.

 

[Gren71]

The 14.x volts is the voltage from the alternator - I know it says "battery voltage" but that's not technically true. It's what I personally call "system voltage" as that's what it in the electrical system at that time. The 12.x is the actual battery voltage. 12.2 is low, to even test these they have to be 12.4 volts - and that meant they had to charge mine before they could even test it. I would think DUH would apply in my case, I mean geesh, I take a truck in with a battery voltage of well under 12.4 and they had to charge it before they could even test it - doesn't that suggest there's something not keeping up? I would not have taken it in if the battery voltage had been 12.6 for example. Maybe the batteries are ok - maybe that's true, but for some reason they aren't getting charged and staying up. The IBS senses the DRAIN on batteries as well.......... so......... next time that stops working and the battery state is down again, I'm taking it to the dealer across the county.

Heh, gotcha.

so is the reading when the truck is off at the red light my main battery then?Or aux?

 

[ShadowsPapa]

Heh, gotcha.

so is the reading when the truck is off at the red light my main battery then?Or aux?

That's what we're not sure of............ mine drops really quickly. I've seen it go down to about 11.8 when sitting in ESS engine off mode.

 

[jebiruph]

thought it would be beneficial to have a diagram for all to work with. Pin 1 goes direct to the aux battery, pin 3 goes through the PCM.

Pin 3 goes to the PCR, not the PCM. The PCR is what connects the batteries in parallel and separates them during an ESS stop and the brief cold start aux battery test.

 

[Gatorized]

Pin 3 goes to the PCR, not the PCM. The PCR is what connects the batteries in parallel and separates them during an ESS stop and the brief cold start aux battery test.

I was thinking Power Control Module rather than Relay - is there another item designated PCM?

 

[ShadowsPapa]

I was thinking Power Control Module rather than Relay - is there another item designated PCM?

PCM over the years, since the 90s anyway, has been "Powertrain Control Module" - handling the engine functions. In the 90s there was a TCM - Transmission Control Module and if I am correct, that has been merged into the PCM.
There was the ABS of course - always has been a module for its own purposes.
Then the BCM (Body Control Module) came along because they needed to split body and security functions out of the PCM. In the 90s the PCM handled the security system and some who transplanted a 4.0 from a Jeep into, say, an AMC Eagle, American, or Spirit or whatever had to deal with the thing not starting because the PCM was expecting certain things to be happening with the body/doors/key. So you had to trick the PCM into thinking the vehicle was unlocked and you had the proper key.

Experts here will have better or more accurate descriptions, I'm sure, but the PCM has also been referred to as the ECM (engine control module) - unless today it IS something different. Different makes call these different things at times, too. Confusing as heck.

So the answer is no, that's all you needed to say.

Other people come along and read this as well - it's for them. Some may wonder where I got that information, how I know the stuff, it's for them. These aren't private conversations. The number of people - non-members - that search the web and read these posts is in the thousands. (and maybe you forget - I've taught classes and am severe ADHD)

Wait a second. You are running your winch through the IBS? Is the IBS capable of handling the max amp draw of your winch? Sorry if this has been discussed before, but I did a quick search and didn't find anything.
.....................................
Thinking more about this ... if you put your winch neg. cable directly onto the neg. battery post, you will provide a ground that does not go through the IBS. I'm not sure you want to do that as a permanent installation.

The interesting thing here is that the winch is grounded to the plate/bumper which is grounded to the frame which is grounded to the body............. which is grounded via a cable from the IBS.
So, no matter where that ground cable is put, it's going to ground through the IBS unless you do go straight to the battery. If you do that, and the engine is running, you'd be pulling through the IBS anyway - alternator through IBS to negative terminal where the winch ground cable would be. So, it's 6 of one, half a dozen of the other.
The silly tech simply moved my winch ground cable from the top of the IBS over to the body ground, which is cabled directly to - gasp - the top of the IBS. He did nothing.



On the surface of it all, it would seem no matter where you put the winch ground cable, it's doing the same thing - some of that current will be going through the IBS. The winch is grounded through itself to the frame and thus body and either way, with the engine running, some power will go through the IBS unless the alternator could possibly handle the entire load (it cannot)

But the bottom line, MY bottom line and reason for posting what I did about them moving that cable is that - there is zero impact on anything. Nothing. The winch on my truck is not and cannot possibly be a parasitic draw. It just can't happen, it's impossible.
There are two reasons - there's a big red switch next to the battery that says OFF- killing power of any sort to the winch, and secondly, there's another switch on the winch itself that chooses either wireless remote OR wired remote. You always leave it in WIRED remote position meaning it's not sitting using power for some RF signal.

 

[ShadowsPapa]

Back to the original processes behind this very thread, got derailed on the winch BS, through IBS, not IBS and so on......m

Anyway, checked my battery voltage last night at 11pm
It was 12.29
I put my 800mA battery minder on it at about 11:05 last night
Today at 8:30am I checked voltage with the 800mA charger still attached but reading "fully charged" (LED was off).
Voltage was 12.81 at 8:30
I disconnected the charger and waited 10 minutes and checked the battery voltage (in system, connected, charger off and disconnected)
Battery voltage was 12.79
I will measure again in an hour or so. This is at least proof that at the measly, skimpy rate of 800mA (not even 1 amp) these will charge fully in roughly 9 hours.

 

[Maximus Gladius]

I for one appreciate your over (ADHD)explanation of details. Before reading this forum, I had no clue what AGM (absorbant glass mat) batteries were nor knew how to care for or even that I had to care for these things. When it matters to me or when I have no clue and it should matter to me, it’s all in the right details expressed even if it’s just one item out of 50 that jumps out and turns the “light” on.

 

[chorky]

Yes, if the aux battery isn’t charging, the truck will shut down. Don’t ask how I know. My aux battery was down to 10 volts while I was troubleshooting. My JT‘s digital display (speedometer) was showing low voltage, before the truck turned off in my driveway. That’s also how I realize that voltage displays the auxiliary battery voltage/charging on pin 3.

This is concerning. for a variety of reasons. You would think there would be some sort of 'safety net' in place where the aux battery gets disconnected from the main if it falls below X volts so as to not permanently damage the main battery. After all - even having a vehicle in limp mode is better than no vehicle when one is away from civilization.

Back to the original processes behind this very thread, got derailed on the winch BS, through IBS, not IBS and so on......m

Anyway, checked my battery voltage last night at 11pm
It was 12.29
I put my 800mA battery minder on it at about 11:05 last night
Today at 8:30am I checked voltage with the 800mA charger still attached but reading "fully charged" (LED was off).
Voltage was 12.81 at 8:30
I disconnected the charger and waited 10 minutes and checked the battery voltage (in system, connected, charger off and disconnected)
Battery voltage was 12.79
I will measure again in an hour or so. This is at least proof that at the measly, skimpy rate of 800mA (not even 1 amp) these will charge fully in roughly 9 hours.

Very interesting thread, and I appreciate the info shared. It makes me think that there might be more than one problem going on. I can for sure see how batteries from the factory are already bad. I mean from the point of their manufacturer, to the install of the Jeep, to when the Jeep gets to an owner can be a long time with many short engine run times that cause the battery to drain. So it's very likely, to me, in these high electrical use vehicles that the batteries are easily being damaged to a point of no return (below 80% SOC) before they even reach an owner.

However, based on some responses here I am under the thought currently that there absolutely MUST be another source for power drain. Of course there already is - for example the alarm system. But there must be another source that is causing some good amount of drain in addition to a bad aux battery.

Has anybody used a battery disconnect and tested the engine off A draw? Right after key off, and then maybe 10 minutes after engine off, and again an hour after? I am willing to bet it is quite substantial.

Another consideration - is most people dislike ESS. So maybe this is encouragement to just do a Genesis dual kit, remove the aux battery entirely, and never have to worry about it? Although, I would be interested in seeing if someone with a Genesis kit is experiencing some decent amount of battery drain of the main battery after a few days of the vehicle sitting....

Also, the gladiators come from the factory WITH an AGM correct? so it couldn't possibly be that the vehicle's charging system itself is not set up to charge properly AGM batteries.

I drove another Gladiator just yesterday - it only had 15 miles on it between factory build, and the dealers PDI process. So I was essentially the very first person to take it out for a test drive. Right from the get go the Aux battery was showing not charged. So My first thought above that these are bad from some part of the manufacture process must be valid.

 

[ShadowsPapa]

I for one appreciate your over (ADHD)explanation of details. Before reading this forum, I had no clue what AGM (absorbant glass mat) batteries were nor knew how to care for or even that I had to care for these things. When it matters to me or when I have no clue and it should matter to me, it’s all in the right details expressed even if it’s just one item out of 50 that jumps out and turns the “light” on.

It was in another forum where AMC guys were talking about replacing their batteries with new-fangled Optima batteries and other charging systems due to their installations of fuel injection systems and other things requiring a lot more CLEAN power and constant voltages that I learned about these batteries a couple years ago or so.
In college, we had to write, in detail, how thing like, for example, the then Ford direct-drive 4.5" starter worked, from the battery to the starter pinion and flywheel ring gear, every switch, every field winding. Same for charging systems. (and for me personally, I do apologize, but look up the facts on ADHD, the real ones, and take it times 10. I said F the meds 3 or 4 years ago)

 

[Maximus Gladius]

Hope you’re on CBD at least.

 

[ShadowsPapa]

Also, the gladiators come from the factory WITH an AGM correct? so it couldn't possibly be that the vehicle's charging system itself is not set up to charge properly AGM batteries.

Yes, and that is one reason there's the IBS (battery sensor) - because they need to monitor battery temperature and SoC (state of charge), what goes in and what comes out, and adjust voltages accordingly.
If you have been driving your truck a lot, maybe a couple of hours or more on the highway at 70+ mph and the temperatures aren't overly hot, you may see the voltage on the display (off road pages or in the cluster) drop to 12.6 or 12.7 volts. That is because the PCM, through info from the IBS, etc., has decided the batteries have gone through all phases of charging and are fully charged. The system is in maintenance mode and putting out only enough to keep the electric system going. It's not charging any more.
In the past, the charging was regulated at a set voltage, typically 13.8 to 14.2 (for AMC and GM vehicles, etc.). That's not enough to get AGM batteries through charging, and it's too much once they are charged. They are sealed so making them hot, too much charge voltage, etc. will kill 'em.
Plus, it wastes power because an alternator takes multiple horsepower when loaded up. I think I recall that when extra torque and HP is needed on these, the PCM will cut the alternator back. I can kill the 1.5 hp electric motor on my alternator test stand.

I note on the BMW forums some guy decided he wanted to get rid of that "I don't see any purpose for it" IBS and the others were slapping him down pretty good saying that's a good way to kill batteries........

I find info saying 13.4-13.6 to maintain a charged battery (float mode), max of about 15 when it's low and here's something interesting - Nissan says if testing a customer battery and the current battery voltage is 12.0 volts, toss it and replace it. Now that is interesting.

Hope you’re on CBD at least.

Now there's one I'll have to Google or Bing!
I was on 60mg or whatever they call it adderall. It's a controlled substance, the script process was a pain in the butt (has to be done in person, not phone, not email, etc.) so running around town after a script every 30 days (the max time they can do) and traveling with it - and trying to spread that dose out over a day, once I retired especially, my wife puts up with me. She's a saint.

 

[Maximus Gladius]

I’ll PM you.

 

[jac04]

Other people come along and read this as well - it's for them. Some may wonder where I got that information, how I know the stuff, it's for them. These aren't private conversations. The number of people - non-members - that search the web and read these posts is in the thousands. (and maybe you forget - I've taught classes and am severe ADHD)

Oh, I completely understand. But, IMO it is very important for everyone reading your replies to understand that just because you found some information on the internet and regurgitated it here does not mean that you actually know it.

Sponsored