I love it when that happens LOL. Sure, honey, it's fixed! Yup, I did it.
I just changed my aux battery after having the stop start error. After the battery change I’m still getting the error. When you reset the ibs do you need to fully disconnect it like in shadowpaps picture? Or is just disconnecting the whole harness from the battery sufficient?IBS reset is very simple, especially if you are charging the batteries anyway.
Normally you should never charge by connecting below the IBS - that way it "senses" the charge going in.
But if you are going to do the whole thing, meaning charging both batteries and resetting the IBS, it won't matter.
Charge each battery independently so you can track how each acts while charging.
That means pull the ground cables off the top of the IBS - intelligent battery sensor.
Remove the IBS from the main battery negative terminal and set it aside - leaving it off disconnected for 10-15 minutes causes it to reset - to default.
Separate the two ground cables. The "thinner" black cable is the aux battery ground. You can connect to it and the main battery + to charge the aux battery since the two are tied together at the + terminal as well.
Charge the main battery as well.
Note the voltage of each right after charging, then wait a few hours and check the voltage of each again. Being disconnected, there should be no drain on them so they should maintain a full charge of around 12.7 volts (maybe better)
Then you can put it all back together again, install IBS, install ground cables.
I have more details and pics if needed.
This is the IBS -
This is a 2020 where the top black cable, the smaller one, is the aux battery ground cable.
The other one, on the right in this pic, is the main battery ground.
Take both off the IBS, take one cable off the other cable, and connect battery charger negative to the smaller of the two and the positive battery charger clamp on the main battery positive - that can be used to charge the aux battery as well as the main battery.
For 2021 and later, the two black cables are reversed - Jeep made the top cable the larger one - the ground for the batteries, and the lower cable with the larger end that has the stud is the aux battery ground on 2021 and later.
That's rather low for just shy of a couple of days.........
Part of the issue with batteries in general is that it takes more, longer, to charge the last few percent.
With lithium batteries as used in vehicles and other stuff the first 80% or so is pretty quick, the last 10% or so takes longer.
These follow similarly - getting up to 90% or so isn't bad, that last few percent makes me impatient as heck!
So it would just make sense that it takes longer to get them up to that top level by driving.
Unless it's a premature failure of one, both batteries should be replaced at the same time. Removing the IBS from the negative post should be sufficient, but some recommend complete disconnect for at least ten minutes. Fully charge both batteries before putting it all back together.
Ok good to know. Both my batteries came with the jeep when I got it new 3.5 years ago- so I figured the aux was failing first. I’ll replace the main now and see if that fixes things.
Yeah, there's a lot of talk out there.......... but really either one can fail first.
Oil temp? cat converter temp? One of the other 2 dozen things that have to line up with Venus during a blue moon?
I thought about that. Not so much Cat temp or oil temp though. I think it was at a stable operating temp. Does it check battery temp through IBS? When my 2020 would shut off at a railroad crossing or a long red light, "battery charging" message would briefly come on before switching back to ready. The rental JL would briefly display "not ready". That is why I question if there was a change for the later models.
Battery temperature is tracked as well - if it's too hot, it cuts the charging rate (voltage).
