Your battery voltage - truck off and at rest

[ShadowsPapa]

I wonder if it would be the same or different if both batteries were the same size and capacity….

My wondering exactly because if two batteries are at the same level, but different capacities, they'd need to reach the different stages of charging at different times. One would be read for the steady voltage state at a lower level and the other would not.
Charging at the same 10 amp setting one battery took hours longer to charge than the other one.

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[Rusty PW]

My wondering exactly because if two batteries are at the same level, but different capacities, they'd need to reach the different stages of charging at different times. One would be read for the steady voltage state at a lower level and the other would not.
Charging at the same 10 amp setting one battery took hours longer to charge than the other one.

Hey ShodowsPapa. Have you desulfated your batteries? Just a thought.

 

[ShadowsPapa]

Hey ShodowsPapa. Have you desulfated your batteries? Just a thought.

Yes.
And the new charger automatically detects and did the "repair mode" for a while before switching to regular charge on the aux battery.
I ran my small BatteryTender on both a week ago and it has a constant desulfate mode.
After using the small "charger" and then charging both twice with the larger charger, the batteries actually see - so far - to be doing better and the truck actually cut voltage on our trip today. It's working more like it did a year or so ago.

Maybe a combination of exercising the batteries, using a charger that took them through all modes - constant current, constant voltage (absorption) and then the completion phase where voltage drops to a steady lower level of about 13.2 volts and slowly tapers off amperage, helped. TIME will tell, I guess.
But the truck actually sort of echoed how the charger worked while driving it today while in the past it was like the batteries never left the mode that required the higher voltage.

 

[DobaMark]

My stop/start still works after the three times of external charging. i don't know if my battery charger did any repair functions - it may as it's a newer charger with an AGM setting.
Anyway, I guess the dealer won't be replacing the batteries since it's working. I'll probably be on my own and out of warranty when they finally fail. At least I can probably get better batteries than Jeep used.

 

[ShadowsPapa]

Voltage down to 12.35 after 22 hours.
I have found that we have the IBS version at least 3.0
And I now know why mine didn't require all of those 8 hours of rest between 5 start cycles and days of learning.

These can learn in one or two starts and only a few hours in between.
I also found the ESS threshold for battery SoC - 65% - so they can be pretty low before ESS stops working which tells me the IBS said my battery SoC was under 65%!
That means my batteries were less than 2/3 full charge. Definitely concerning.

IBS V3.0 learning cycle -
IBS learning needs 1-2 key cycles and 2-4 hours of quiescent/sleep time (no charge in
or no charge out of the battery).
And the no charge in, no charge out is defined as ->
less than 250mA + or - 50mA
*so less than 200mA to 300mA

Once the IBS is reset any battery charging or any discharge needs to go through the IBS.
Fine to do what I did - charge batteries fully, IBS removed from system to reset it, and then put it all back together but any other charging after that needs to go in through the IBS and not directly to the battery post.

Take all power (+) use out as normal as far as positive but ground only through the IBS - meaning connect all additional load grounds to the top of the IBS or body ground.
Don't ground lights and other loads under the IBS or directly to the battery negative post or IBS clamp bolt.
This is straight from Jeep.

 

[Erievon]

Also - take all power use out through the IBS - don't connect lighting and so on directly to the battery, connect all additional loads to the top of the IBS.
This is straight from Jeep.

Ok Papa...splain. If the IBS is on the negative terminal, where should I pick up power for aux lights if not the positive terminal of the battery? From stud 3 on the fuse box? (I don't have the aux switches).

 

[ShadowsPapa]

Ok Papa...splain. If the IBS is on the negative terminal, where should I pick up power for aux lights if not the positive terminal of the battery? From stud 3 on the fuse box? (I don't have the aux switches).

Yeah, I should have clarified. Take the ground from the body or the top of the IBS, don't go direct with a ground to the negative post or the screw that clamps the IBS to the battery post.
Positive as usual, my bad. Didn't explain that is for ground. There's been talk of where to ground things and some say body, others say go direct to battery -
Jeep says body or top of the IBS for ground.
Good catch, I didn't do well at all wording that.

 

[ShadowsPapa]

Ok Papa...splain. If the IBS is on the negative terminal, where should I pick up power for aux lights if not the positive terminal of the battery? From stud 3 on the fuse box? (I don't have the aux switches).

There, I fixed it (I hope) -thanks.

 

[Erievon]

Ok whew, I use the stud on the fender for negative. It makes sense then, IBS wants to track every amp in and out, and they don't want their IBS fried.

 

[chorky]

Interesting thing I noticed today. Truck has been sitting since saturday. Its been cold’ish. Not anywhere near what it usually is in mid winter. 28 this morning. Jeep had warmed up but seat and steering wheel heaters were in. The instrument cluster said charge was 15.0 volts! Most I have seen prior was 14.7v. 15 seems high. I will try and check battery voltage when I get home but it likely will have a surface charge.

 

[ShadowsPapa]

Mine is back to voltage always being 14.4 to 14.7 when I'm driving it. Odd that it was down in the 13s like it was on back a year ago and beyond. It was like - yeah, this is how it should be, and now it's back again. But - ESS is working exactly like designed at this point so a little more checking, testing, monitoring, but it is better than it was. Apparently full charging of both batteries twice and resetting the IBS at least made it better.

 

[chorky]

Mine is back to voltage always being 14.4 to 14.7 when I'm driving it. Odd that it was down in the 13s like it was on back a year ago and beyond. It was like - yeah, this is how it should be, and now it's back again. But - ESS is working exactly like designed at this point so a little more checking, testing, monitoring, but it is better than it was. Apparently full charging of both batteries twice and resetting the IBS at least made it better.

That's good to hear. I hope it stays that way! But, good to know that a BMS reset might have resolved the issue, I doubt the dealer would have been able to do that much. I just checked mine when I got home. 12.57.

 

[ScottLars]

My truck was parked for 4 days without running at all. Checked voltage at main battery terminals with handheld multimeter and read 12.2 volts. Went ahead and put it on automatic (AGM compatible) charger/tender. Hooked up positive to main battery terminal and negative to top of IBS sensor. It charged for about 4-5 hours before reporting 100% and went into float mode. Did not drive or turn on truck until the next morning.

Next morning drove to work approx. 10 minute. Stayed parked at work all day approx. 10 hours. Decided to hook up ODB and JSCAN app. Set to monitor IBS state of charge. It was reporting 87%. After 10 minute drive home it went up to 88%. Truck was parked and not ran all night (14 hours).

This morning hooked back up with JSCAN before driving to work. Reading was now 83%. Climbed to 84% after the 10 minute commute.

Would like to know why the state of charge dropped 5% overnight. Seems like some very high parasitic draw. Nothing obvious is plugged in or left on.

Batteries are only 4 months old. DieHard brand.

 

[Mr._Bill]

My truck was parked for 4 days without running at all. Checked voltage at main battery terminals with handheld multimeter and read 12.2 volts. Went ahead and put it on automatic (AGM compatible) charger/tender. Hooked up positive to main battery terminal and negative to top of IBS sensor. It charged for about 4-5 hours before reporting 100% and went into float mode. Did not drive or turn on truck until the next morning.

Next morning drove to work approx. 10 minute. Stayed parked at work all day approx. 10 hours. Decided to hook up ODB and JSCAN app. Set to monitor IBS state of charge. It was reporting 87%. After 10 minute drive home it went up to 88%. Truck was parked and not ran all night (14 hours).

This morning hooked back up with JSCAN before driving to work. Reading was now 83%. Climbed to 84% after the 10 minute commute.

Would like to know why the state of charge dropped 5% overnight. Seems like some very high parasitic draw. Nothing obvious is plugged in or left on.

Batteries are only 4 months old. DieHard brand.

There will always be some draw with these. The computers do not turn off, only the user interface is shutdown. The alarm system is also on. The USB ports continue to supply power if an active device is connected. The remote start feature keeps things on as it has to listen for a start command. The receiver is always on listening for an unlock command from the FOB. The Proximity Locks keep the door handles active waiting for instructions to unlock the doors.

 

[ScottLars]

There will always be some draw with these. The computers do not turn off, only the user interface is shutdown. The alarm system is also on. The USB ports continue to supply power if an active device is connected. The remote start feature keeps things on as it has to listen for a start command. The receiver is always on listening for an unlock command from the FOB. The Proximity Locks keep the door handles active waiting for instructions to unlock the doors.

I understand there will always be a current draw on the vehicle, but to draw down the battery by 5% overnight seems excessive.

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