How long does it actually take for the BMS relearn?

[guarnibl]

Hi folks,

Left on vacation for about a month and came home to a dead Gladiator. It was on a Noco 10 the entire time, and it had an X (error) indicator lit on the screen. The last time this happened was on my two door JL, and it was due to the AUX battery going bad. Wouldn't charge fully/hold a charge. It would go 'green' quickly on the tender, but then die again a few days later. And it also was starting to show the 'X' error light on the tender on occasion.

Anyway, I have the ecodiesel, so swapping the AUX battery is insanely easy. So I took out both OEM batteries and replaced them with two from O'reilly (Super Starts; AUX14J and 94R H7 850). Around ~$400 or so. 4 year non-prorated warranty. Figured that was better than going OEM. I don't play to delete the ESS/AUX given it's easy to replace. I did delete it on my previous JL.

Replacing went smooth -- disconnected main battery negative terminal first, wrapped cable it in a microfiber cloth, disconnected positive terminal, wrapped cable in microfiber cloth. Removed the battery placement holder bracket, then removed battery. Then took out the two screws below the tray, removed that top piece, and repeated the procedure for the AUX battery. Reversed those steps (after swapping the posts on the AUX). Started up right away.

The only thing I noticed was that my ESS doesn't work -- and my voltage is stuck at a constant ~13.9-14.1. I drove it for 45 minutes. No change.

After searching here, it seems I'm in a BMS relearn that might take several days? I think my N1/N2/N3 etc fuses might be difference since it's the ecodiesel, but could be wrong... as mine seem to end at N6 rather than N7. Anyways, I didn't volt check the new batteries, so maybe they weren't all the way up after sitting. The AUX battery had a date code of 9/25 and the MAIN battery had a date code of 11/25. But I figured driving for nearly an hour it would eventually drop down to low 13's high 12's -- indicating the alternator no longer was charging the battery since it was full. But here we are. I also volt checked N1/N2 etc and they're 13.95/14.12 respectively when running. N3/N4/N5 etc also seemed to read similar. So I assume I didn't do anything wrong/didn't blow any high current fuses when swapping these batteries.

With key cycle set to 'RUN' -- Jeep not running, it was sitting at like ~12.5-12.7. But obviously I know you can't read them independently of each other.

Thoughts? I read the other IBS Clear/Reset thread, so my gut feeling is everything is normal and it's just a relearn thing, but I did put a multimeter on those high powered fuses (or whatever they're called), and it was reading ~13.95/14.12 which makes me question if that's actually the case, or if something else is going on. I would have assumed it would have fully charged in that 45 minute drive, and like I said key off says 12.5-12.7 when in RUN mode.

Only aftermarket electronics would be winch and steps (rock slide engineering).

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[WILDHOBO]

Hi folks,

Left on vacation for about a month and came home to a dead Gladiator. It was on a Noco 10 the entire time, and it had an X (error) indicator lit on the screen. The last time this happened was on my two door JL, and it was due to the AUX battery going bad. Wouldn't charge fully/hold a charge. It would go 'green' quickly on the tender, but then die again a few days later. And it also was starting to show the 'X' error light on the tender on occasion.

Anyway, I have the ecodiesel, so swapping the AUX battery is insanely easy. So I took out both OEM batteries and replaced them with two from O'reilly (Super Starts; AUX14J and 94R H7 850). Around ~$400 or so. 4 year non-prorated warranty. Figured that was better than going OEM. I don't play to delete the ESS/AUX given it's easy to replace. I did delete it on my previous JL.

Replacing went smooth -- disconnected main battery negative terminal first, wrapped cable it in a microfiber cloth, disconnected positive terminal, wrapped cable in microfiber cloth. Removed the battery placement holder bracket, then removed battery. Then took out the two screws below the tray, removed that top piece, and repeated the procedure for the AUX battery. Reversed those steps (after swapping the posts on the AUX). Started up right away.

The only thing I noticed was that my ESS doesn't work -- and my voltage is stuck at a constant ~13.9-14.1. I drove it for 45 minutes. No change.

After searching here, it seems I'm in a BMS relearn that might take several days? I think my N1/N2/N3 etc fuses might be difference since it's the ecodiesel, but could be wrong... as mine seem to end at N6 rather than N7. Anyways, I didn't volt check the new batteries, so maybe they weren't all the way up after sitting. The AUX battery had a date code of 9/25 and the MAIN battery had a date code of 11/25. But I figured driving for nearly an hour it would eventually drop down to low 13's high 12's -- indicating the alternator no longer was charging the battery since it was full. But here we are. I also volt checked N1/N2 etc and they're 13.95/14.12 respectively when running. N3/N4/N5 etc also seemed to read similar. So I assume I didn't do anything wrong/didn't blow any high current fuses when swapping these batteries.

With key cycle set to 'RUN' -- Jeep not running, it was sitting at like ~12.5-12.7. But obviously I know you can't read them independently of each other.

Thoughts? I read the other IBS Clear/Reset thread, so my gut feeling is everything is normal and it's just a relearn thing, but I did put a multimeter on those high powered fuses (or whatever they're called), and it was reading ~13.95/14.12 which makes me question if that's actually the case, or if something else is going on. I would have assumed it would have fully charged in that 45 minute drive, and like I said key off says 12.5-12.7 when in RUN mode.

Only aftermarket electronics would be winch and steps (rock slide engineering).

I’m guessing it’ll start working in a couple days. I’d leave it for a bit before digging deeper. But that’s me.

 

[guarnibl]

I’m guessing it’ll start working in a couple days. I’d leave it for a bit before digging deeper. But that’s me.

Yeah, that's kinda what I'm thinking (or HOPING anyway). I've only ever replaced the main battery -- somehow my AUX battery I think made it 5 years. I really need to get the whole concoction that lets me see independent battery voltage that someone else posted in another thread.

If it doesn't start working, the only other thing I could think is BMS sensor, or high amp fuse. I don't think parasitic draw would cause it from steps/winch.

 

[guarnibl]

So I went out for another drive and after 10 minutes it’s down to 12.8-12.9 on the voltage while driving according to the EVIC and off road pages. Interestingly enough though it still says stop start not ready battery charging. I thought 12.8-12.9 was range where the alternator isn’t really charging the battery anymore though. But perhaps this is once again part of the learn cycle.

 

[ShadowsPapa]

Hi folks,

Left on vacation for about a month and came home to a dead Gladiator. It was on a Noco 10 the entire time, and it had an X (error) indicator lit on the screen. The last time this happened was on my two door JL, and it was due to the AUX battery going bad. Wouldn't charge fully/hold a charge. It would go 'green' quickly on the tender, but then die again a few days later. And it also was starting to show the 'X' error light on the tender on occasion.

Anyway, I have the ecodiesel, so swapping the AUX battery is insanely easy. So I took out both OEM batteries and replaced them with two from O'reilly (Super Starts; AUX14J and 94R H7 850). Around ~$400 or so. 4 year non-prorated warranty. Figured that was better than going OEM. I don't play to delete the ESS/AUX given it's easy to replace. I did delete it on my previous JL.

Replacing went smooth -- disconnected main battery negative terminal first, wrapped cable it in a microfiber cloth, disconnected positive terminal, wrapped cable in microfiber cloth. Removed the battery placement holder bracket, then removed battery. Then took out the two screws below the tray, removed that top piece, and repeated the procedure for the AUX battery. Reversed those steps (after swapping the posts on the AUX). Started up right away.

The only thing I noticed was that my ESS doesn't work -- and my voltage is stuck at a constant ~13.9-14.1. I drove it for 45 minutes. No change.

After searching here, it seems I'm in a BMS relearn that might take several days? I think my N1/N2/N3 etc fuses might be difference since it's the ecodiesel, but could be wrong... as mine seem to end at N6 rather than N7. Anyways, I didn't volt check the new batteries, so maybe they weren't all the way up after sitting. The AUX battery had a date code of 9/25 and the MAIN battery had a date code of 11/25. But I figured driving for nearly an hour it would eventually drop down to low 13's high 12's -- indicating the alternator no longer was charging the battery since it was full. But here we are. I also volt checked N1/N2 etc and they're 13.95/14.12 respectively when running. N3/N4/N5 etc also seemed to read similar. So I assume I didn't do anything wrong/didn't blow any high current fuses when swapping these batteries.

With key cycle set to 'RUN' -- Jeep not running, it was sitting at like ~12.5-12.7. But obviously I know you can't read them independently of each other.

Thoughts? I read the other IBS Clear/Reset thread, so my gut feeling is everything is normal and it's just a relearn thing, but I did put a multimeter on those high powered fuses (or whatever they're called), and it was reading ~13.95/14.12 which makes me question if that's actually the case, or if something else is going on. I would have assumed it would have fully charged in that 45 minute drive, and like I said key off says 12.5-12.7 when in RUN mode.

Only aftermarket electronics would be winch and steps (rock slide engineering).

You had it on a NOCO the entire time - depends on what charger it is, the batteries may not have been "fully charged". Most don't do a great job of floating a battery once charged, and not all have the push to fully charge. They are "get by" chargers.

Best bet would have been to use a charger of at least 5 to 10 amp and start a fresh charge. IF yours charged then went into a float mode - might not have been enough to keep them up.

It generally "relearns" in a few hours.

I have a winch - but of course, for safety, with a disconnect so it can't possibly drain a battery, and the steps - meh, no problem with the RSE power steps.

But make sure you wire ALL accessories to the top of the IBS (Intelligent Battery Sensor)

Did you ever use a real volt meter on the battery to see what the real voltage is with the truck OFF?
Don't go by the truck telling you.

 

[WILDHOBO]

Yeah, that's kinda what I'm thinking (or HOPING anyway). I've only ever replaced the main battery -- somehow my AUX battery I think made it 5 years. I really need to get the whole concoction that lets me see independent battery voltage that someone else posted in another thread.

If it doesn't start working, the only other thing I could think is BMS sensor, or high amp fuse. I don't think parasitic draw would cause it from steps/winch.

Winch should draw nothing if not in use. The steps do, but not a ton. I have the same steps.

 

[WILDHOBO]

So I went out for another drive and after 10 minutes it’s down to 12.8-12.9 on the voltage while driving according to the EVIC and off road pages. Interestingly enough though it still says stop start not ready battery charging. I thought 12.8-12.9 was range where the alternator isn’t really charging the battery anymore though. But perhaps this is once again part of the learn cycle.

Don’t get caught up in the voltage while it’s running. Smart alternator. It’ll vary wildly with nothing wrong.

 

[guarnibl]

You had it on a NOCO the entire time - depends on what charger it is, the batteries may not have been "fully charged". Most don't do a great job of floating a battery once charged, and not all have the push to fully charge. They are "get by" chargers.

Best bet would have been to use a charger of at least 5 to 10 amp and start a fresh charge. IF yours charged then went into a float mode - might not have been enough to keep them up.

It generally "relearns" in a few hours.

I have a winch - but of course, for safety, with a disconnect so it can't possibly drain a battery, and the steps - meh, no problem with the RSE power steps.

But make sure you wire ALL accessories to the top of the IBS (Intelligent Battery Sensor)

Did you ever use a real volt meter on the battery to see what the real voltage is with the truck OFF?
Don't go by the truck telling you.

Noco Genius 10 is what I'm using to tender. So that's a 10 amp smart charger that has been very very good to me over the past several years. Should be enough to keep it more than topped off as per spec sheet. The 'error' light (X light on the Noco) is what indicated to me that there's likely a bad cell in one of the batteries. That's what it was on my 2 door when it was dead dead.

But yeah, I just went straight to Oreilly's after that and bought a new aux and main, since I know the OEM batteries not the best. I'm going to throw the old ones on the Noco Genius 10 tomorrow and see if they'll hold a charge. If the main battery holds, I may just return the new main, as it was ~$259 and well, the main is only about 18 months old. Now it's at ~6.5 volts, so it may not come back from the dead once it's that low. But my gut says the AUX battery being at 4.4 volts is the one with the bad cell.

And yep, did use an actual multimeter, with everything disconnected. Thankfully, it's easy on the diesel to take both batteries out... they're literally on top of each other. 2 door was annoying.

Overall, I've driven it about ~2 hours total now and it's sitting at 12.8~12.9 while running. Still says ESS is disabled due to battery charging though. Guess we'll see in a few days.

 

[Chasm]

Don’t get caught up in the voltage while it’s running. Smart alternator. It’ll vary wildly with nothing wrong.

Yep, varying wildly is the norm. Mine on the other hand is locked above 14v all the time because the batteries are already failing. Had it in the dealer a couple weeks ago and they said they aren't bad enough to replace. They charged them and said they should be fine. For a few day I got the normal variance. Now it's back to constant high charge.

 

[WILDHOBO]

Noco Genius 10 is what I'm using to tender. So that's a 10 amp smart charger that has been very very good to me over the past several years. Should be enough to keep it more than topped off as per spec sheet. The 'error' light (X light on the Noco) is what indicated to me that there's likely a bad cell in one of the batteries. That's what it was on my 2 door when it was dead dead.

But yeah, I just went straight to Oreilly's after that and bought a new aux and main, since I know the OEM batteries not the best. I'm going to throw the old ones on the Noco Genius 10 tomorrow and see if they'll hold a charge. If the main battery holds, I may just return the new main, as it was ~$259 and well, the main is only about 18 months old. Now it's at ~6.5 volts, so it may not come back from the dead once it's that low. But my gut says the AUX battery being at 4.4 volts is the one with the bad cell.

And yep, did use an actual multimeter, with everything disconnected. Thankfully, it's easy on the diesel to take both batteries out... they're literally on top of each other. 2 door was annoying.

Overall, I've driven it about ~2 hours total now and it's sitting at 12.8~12.9 while running. Still says ESS is disabled due to battery charging though. Guess we'll see in a few days.

Yeah. 4.4 isn’t coming back.

 

[WILDHOBO]

Yep, varying wildly is the norm. Mine on the other hand is locked above 14v all the time because the batteries are already failing. Had it in the dealer a couple weeks ago and they said they aren't bad enough to replace. They charged them and said they should be fine. For a few day I got the normal variance. Now it's back to constant high charge.

Dealers annoy the crap out of me. I get that they have internal policies to follow, but I hate bureaucracy so much. Because you just wasted your time, and they will certainly fail.

 

[guarnibl]

Yeah. 4.4 isn’t coming back.

Exactly. It likely has two dead cells. I'm 50/50 on the main battery that's at 6v coming back.

I wish during the learning process the EVIC would just tell you. I'm sure it was just considered too verbose for users and thus hidden.

 

[ShadowsPapa]

ALWAYS fully charge new batteries before installation.
Voltages that low - meh, not a great sign for either battery.

Frankly, I'd put two NEW batteries in instead of one that's been that low and has any age on it with a new battery. Not a good mix

The relearning isn't a big deal. It will have learned so fast it's not worth telling people - hey, we're in learning mode and who the heck is even going to know or care anyway?

Two new batteries and be done with it.
Charge both first, then install.
Allow a few hours (not days, hours) for it to relearn.
Get a batteryminder type of device that is made for maintaining batteries - too many chargers charge fine, but for maintaining while sitting - not very good.

I don't know what VOLTAGE the NOCO "maintains" at but some say it's crazy high. They only say they "use a low amperage pulse to maintain" - that's weird to me.

https://bobistheoilguy.com/forums/threads/noco-genius-10-burning-out-batteries.390559/

I'll stick with my CTEK and BatteryMinders. I know that will start a flame war! LOL - oh, well - they do great for me and I've taken batteries out over 10 years.

 

[WILDHOBO]

Exactly. It likely has two dead cells. I'm 50/50 on the main battery that's at 6v coming back.

I wish during the learning process the EVIC would just tell you. I'm sure it was just considered too verbose for users and thus hidden.

I don’t think 6v has a shot unfortunately

 

[guarnibl]

I don’t think 6v has a shot unfortunately

It's 50/50. I've had them come back from 6v before, but never 4v. My previous 392 had a battery get down to like 6.6 or something and it came back and lasted another 2 years. However, that didn't have an AUX battery connected to the system, and it never got an 'X' on the charger. So I'm a bit more skeptical on this time around.

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