3.6L ESS IBS Information

[cbrenthus]

@cbrenthus,

Maybe you already know this, but batteries are way more efficient at higher temperatures. Chemical interactions at the molecular level naturally have higher kinetic energies at higher ambient temperature. This translates into higher voltage as temperature increases. Also lower voltage as temperature decreases.

If your battery has a low charge already, colder temperatures will naturally make things worse.

Jay

Yes, that is what I figured was happening, I was just amazed that such a small temp difference would do it. However, that was just for a month or 2, now it isn't doing it at all.

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[Jebiruph]

Hi all,

Really great thread. So many dynamic variables to grapple with but everyone here is making this over-the-top complicated contraption way more understandable. Especially to Jerry, really appreciate all your knowledge and willingness to share it with the rest of us. Kudos and thanks to all.

I'd like to provide another data point for your consideration.

I too have been struggling with constant high alternator output (typically >14.5v) regardless of whether at idle or not. It basically seemed like I had a bad battery. Several trips to the dealer always resulted in no trouble found (NTF). Both batteries load tested OK.

I have a 2019 Sport S 3.6L Auto (20K miles) completely stock ESS circuit. Very tempted to do Jerry's bypass but have held off because I'm the oddball who actually doesn't mind the Auto Stop/Start functionality. Truthfully, I enjoy it in most circumstances, but I digress.

My ESS routinely would be disabled due to "Battery Protection Mode". The only way it seemed I could keep the ESS working was to put a battery tender on my rig every other day or so. The tender always went into float mode quickly, within an hour or two. So this convinced me the batteries (in parallel) where fine.

Finally I got fed up, went and asked to see the Service Manager at the dealership. After a long discussion (based on all the great input from this thread) and to his credit, he agreed to take a small road trip with me. He also knew I had been in several times already, all resulting with NTF.

Sure enough, after the fourth or fifth red light (ESS event), the ESS stopped working with it's usual "Battery Protection Mode" complaint. The EVIC was consistently at or above 14.5v during the entire drive.

I was finally able to convince these people that a) my batteries are not adequately being charged or b) the IBS monitoring system isn't working as intended.

He 'reluctantly' had a tech replace the IBS with both of them saying that they never seen one go bad before.

Immediately after however, the alternator output dropped into the mid 13v range and I have yet to see ESS disabled due to any battery protection issue.

So I have a data point that strongly enforces your ideas of IBS functionality being key to running with higher than expected alternator output voltages.

On even short (<10 mile) trips, I now routinely see my EVIC display indicate high 12v readings.

Hope this helps enlighten some of your IBS discussion points.

Jay

I've been monitoring my battery voltage for about 2.5 years and it's almost always around 14.5v (except maybe my 16 day 6k mile trip) and I don't remember ever having any battery/ESS related warnings or issues. I do try to disable it every time, but it frequently takes a one stop reminder and it always works when I forget to turn it of.

Somewhere I read that the IBS gets reset when you unplug the connector and then it will relearn the battery. I need to try that and that should probably be done whenever the main battery is replaced. Disconnecting both batteries should do the same thing.

From my research in 2018 (when my wife got a new Cherokee) I found some consensus on a Cherokee forum (where they had a few years of experience) that you should replace the IBS when the battery is replaced. Maybe we need to start replacing more of them.

 

[cbrenthus]

Well, I did a full charge with a Noco Genius 3500 set on AGM, and still ESS won't work due to the battery charging. Which is fine by me, I don't have to press the button. As for the battery health, I'm going to run it until it won't start the jeep anymore, while occasionally charging the AUX, and if the main ever dies, I can just hook up the AUX to get it started then get a new battery!

Actually, I also have the AUX disconnected on my pacifica, and I think I'm going to get battery disconnect switches for both, then if one won't start I won't even need a tool to jump it!

 

[TroyBoy]

I now have a single battery system and ran the trickle charger on it overnight. Evic says it is charging 14.6 still. Does that mean the battery is going? Or the IBS is going? The jeep starts fine and the battery charge is at 12.47v using a volt meter.

 

[OldGuyNewJeep]

the battery charge is at 12.47v

That’s not a full charge. What you’re seeing is the same that I saw when my main started to fail...

Even though I could have sought a warranty claim (I did have my AUX replaced for free), I decided to just invest in a good battery: https://www.jlwranglerforums.com/fo...t-question-for-the-experts.66343/post-1412816

 

[WranglerMan]

I now have a single battery system and ran the trickle charger on it overnight. Evic says it is charging 14.6 still. Does that mean the battery is going? Or the IBS is going? The jeep starts fine and the battery charge is at 12.47v using a volt meter.

12.47 seems a tad low, a good quality AGM resting voltage should be in the 12.9 range so you would have to disconnect and charge and then let the surface charge fall off then meter it, if you don’t want to disconnect then do your full charge and then let the surface charge fall off and it should be in the 12.6-12.8 range

What charger are you using, lots of these maintainers don’t bring an AGM up to the correct voltage for the bulk charge and some even float at a lesser charge than what is required so its best to look to the maker of the battery to see what they suggest.

Example I currently run Full River 750 AGM’s and they recommend the bulk charge be kept at 14.5-14.7 for several hours then a float charge be held at 13.3-13.5 and the maintainer I was using barely got to 13.7 for the bulk charge and they advised that would shorten the life of my batteries so I went with what they suggested after sending them the charging curves of the chargers I was considering.

The reason you are seeing the 14+ on the EVIC is because the IBS is not seeing the voltage it needs to see to direct the alternator to fall back and rest or do what I call a relaxed charge, if your JL is parked a lot and not on a charger 14+ is pretty common but if it’s a daily driver or you charge on a regular basis you should see a higher resting voltage and the EVIC should display a lot less.

I pulled my batteries off there weekly charge this a.m and they metered 12.85 after resting 60 mins and the EVIC display was 12.8-12.9 with the engine running and idled and when slowing down to brake the voltage would ramp up to over 14 then once stopped it would drop back to the 12.9 but after it’s parked for 10-12 hrs with the parasitic draw from my dual setup and other things normally associated with the JL my running idled EVIC display voltage is normally 14.2-14.4 but after driving 30 mins or so it slowly drops to the mid 13’s and after an hour or so its in the low 13’s and my metered voltage after sitting for 10-12 hrs is normally 12.6 on average for the crank battery and 12.8 on the full size aux as they are not connected as one once the main drops to 12.7.

So with all my rambling I would say your main crank battery is going out

 

[TroyBoy]

12.47 seems a tad low, a good quality AGM resting voltage should be in the 12.9 range so you would have to disconnect and charge and then let the surface charge fall off then meter it, if you don’t want to disconnect then do your full charge and then let the surface charge fall off and it should be in the 12.6-12.8 range

What charger are you using, lots of these maintainers don’t bring an AGM up to the correct voltage for the bulk charge and some even float at a lesser charge than what is required so its best to look to the maker of the battery to see what they suggest.

Example I currently run Full River 750 AGM’s and they recommend the bulk charge be kept at 14.5-14.7 for several hours then a float charge be held at 13.3-13.5 and the maintainer I was using barely got to 13.7 for the bulk charge and they advised that would shorten the life of my batteries so I went with what they suggested after sending them the charging curves of the chargers I was considering.

The reason you are seeing the 14+ on the EVIC is because the IBS is not seeing the voltage it needs to see to direct the alternator to fall back and rest or do what I call a relaxed charge, if your JL is parked a lot and not on a charger 14+ is pretty common but if it’s a daily driver or you charge on a regular basis you should see a higher resting voltage and the EVIC should display a lot less.

I pulled my batteries off there weekly charge this a.m and they metered 12.85 after resting 60 mins and the EVIC display was 12.8-12.9 with the engine running and idled and when slowing down to brake the voltage would ramp up to over 14 then once stopped it would drop back to the 12.9 but after it’s parked for 10-12 hrs with the parasitic draw from my dual setup and other things normally associated with the JL my running idled EVIC display voltage is normally 14.2-14.4 but after driving 30 mins or so it slowly drops to the mid 13’s and after an hour or so its in the low 13’s and my metered voltage after sitting for 10-12 hrs is normally 12.6 on average for the crank battery and 12.8 on the full size aux as they are not connected as one once the main drops to 12.7.

So with all my rambling I would say your main crank battery is going out

Thanks, I was thinking the same thing. I have an Odyssey 94R coming in a few days. The charger I used is a NOCO Genius5

 

[WranglerMan]

Thanks, I was thinking the same thing. I have an Odyssey 94R coming in a few days. The charger I used is a NOCO Genius5

Just remember the general rule of thumb for battery charging, most makers I conversed with recommended the bulk charge be done in the .20% - .35% of the amp hour rating so for me running a 128 ah dual battery I would need to be at 25-40 amp range and the Odyssey 20 gets me pretty close but on the low end but I conversed with the battery maker and they advised the 20 amp charger would be fine but it needs to hold 14.5-14.7 volts at that amp rating for 4-6 hrs then go to a conditional charge at a lower rating then a float charge.

As you can see getting the correct charge in not so simple and just because it says it’s a battery maintainer or charger does not guarantee it will work with all batteries and with the stock JL it uses different amp hour rated batteries so your possibly overcharging one and fine on the other.

This is why I went to two identical batteries so they both get maintained the same and at once.

 

[TroyBoy]

Just remember the general rule of thumb for battery charging, most makers I conversed with recommended the bulk charge be done in the .20% - .35% of the amp hour rating so for me running a 128 ah dual battery I would need to be at 128ah in these ranges and the Odyssey 20 gets me pretty close but on the low end but I conversed with the battery maker and they advised the 20 amp charger would be fine but it needs to hold 14.5-14.7 volts at that amp rating for 4-6 hrs then go to a conditional charge at a lower rating then a float charge.

As you can see getting the correct charge in not so simple and just because it says it’s a battery maintainer or charger does not guarantee it will work with all batteries and with the stock JL it uses different amp hour rated batteries so your possibly overcharging one and fine on the other.

This is why I went to two identical batteries so they both get maintained the same and at once.

Thanks. I only have one battery now but if I ever want two, I’ll go with the genesis dual battery kit.

 

[WranglerMan]

Thanks. I only have one battery now but if I ever want two, I’ll go with the genesis dual battery kit.

Genesis is what I call the Golden Goose, it’s very shiny and has alot of benefits I was looking for but does have some caveats, the biggest is for a lot is the cost and pricing can range from $800-$1200 depending on the batteries you pick and whether you have it installed or do it yourself and the second thing is the parasitic draw which is kinda what you would not expect from a dual battery system that’s supposed to be better but once you understand what it does yo accept the negatives so it’s a tradeoff and I was willing to do that for what I got in return which was more power for my JL in amp hours and having a backup but one can do that sort of with the stock configuration but I would no want all my accessories all tied to the battery that starts my JL.

In your case since you have one battery and it were say a 64 amp hour battery then a smart charger in the 10-15 amp range would be fine just look at who makes it and see what they recommend for the bulk charge in voltage as amps of charger are only one part of the puzzle, you have to look at things combined plus how long during each stage.

I don’t mean to ramble on but I was amazed when i started looking at chargers and it’s just not one size fits all especially when we are paying top $$ for these AGM batteries and we need to take care of them the best we can for the longest life possible but in the end all batteries start dying from day one of being made we just have to do the best we can in maintaining them.

 

[TroyBoy]

Well I got my Odyssey 94R today and installed it. Here is a charge comparison between my two batteries. I trickle charged my old battery 2 days ago.
Edit: The old battery is actually a 700CCA so that puts its SOH at 98% and SOC at 81%. I can't get it to charge up 100%

Strangely I am still seeing 14.6v on the evic so I am running a trickle charge on the new battery now.

 

[Attaboy55]

I thought I'd start this thread for discussing the operation of the IBS. First is a link to the technical description of the IBS from Bosch. The rest of the post is my interpretations and observations.

https://www.bosch-mobility-solution...s/body-electronics/electronic-battery-sensor/

The IBS (Intelligent Battery Sensor) provides battery status information used by the ESS system to determine if there is enough power to restart the engine from an auto stop. If there isn't, ESS will be disabled.

The Main battery is the starting battery. The IBS is attached to the ground terminal of the Main battery and monitors the battery current, voltage and temperature to calculate the following characteristics of the Main battery;
SOC (state of charge) = percentage of battery charge (deliverable charge)
SOH (state of health) = current ability of the battery to hold a charge (battery ageing)
SOF (state of function) = ability to power a start (prediction of voltage drop under load)

This information along with the current, voltage and temperature are available to the ESS system and can be used to determine the overall condition of the Main battery, I don't know if FCA uses it all or not.

The Aux battery voltage must be monitored during auto stop, low Aux voltage during auto stop should initiate a restart. I am not aware of any other Aux battery monitoring. I attribute a lack of Aux battery condition monitoring for the unexpected Aux battery failures.


The first diagram shows the IBS on the Main battery negative terminal.

This diagram shows how the Main battery current passes through the IBS for monitoring, but the Aux battery current bypasses it during normal operation. The exception being if one battery is charging the other.

(updated 04/13/2019)
Additional 3.6L ESS system information is available here.
3.6L ESS Dual Battery Consolidated Information
https://www.jlwranglerforums.com/forum/threads/3-6l-ess-dual-battery-consolidated-information.2

I wanted to add some observations detailing my experience. I have a 2019 Jeep Wrangler. Lately I have not been driving the vehicle due to surgery ( about 1 1/2 weeks). Got in it today and ESS said in center display NOT READY CHARGING. Ok great so I charged both batteries separately, ( the big battery was charges without any cables attached , just terminals , and the small battery was charged using the cables only . Charged AGM at a rate of 3 amps. Buttoned back up , still illuminating the same display. Took it to jeep dealer and the fix was to unplug the IBS, ( intelligent battery sensor) located at battery terminal on main battery. Tech simply unplugged while the vehicle WAS RUNNING and it reset the display and has not come on again. I also wanted to advise , Jeeps have a few items on them that draw power even when the engine is off. Particularly I was leaving my key fob in the vehicle while home and in the garage . Well, the jeep was using it's brain to look for the fob and as such drawing amperage in doing so . I now keep the fob at least 10" from the jeep.

 

[Rhinebeck01]

I wanted to add some observations detailing my experience. I have a 2019 Jeep Wrangler. Lately I have not been driving the vehicle due to surgery ( about 1 1/2 weeks). Got in it today and ESS said in center display NOT READY CHARGING. Ok great so I charged both batteries separately, ( the big battery was charges without any cables attached , just terminals , and the small battery was charged using the cables only . Charged AGM at a rate of 3 amps. Buttoned back up , still illuminating the same display. Took it to jeep dealer and the fix was to unplug the IBS, ( intelligent battery sensor) located at battery terminal on main battery. Tech simply unplugged while the vehicle WAS RUNNING and it reset the display and has not come on again. I also wanted to advise , Jeeps have a few items on them that draw power even when the engine is off. Particularly I was leaving my key fob in the vehicle while home and in the garage . Well, the jeep was using it's brain to look for the fob and as such drawing amperage in doing so . I now keep the fob at least 10" from the jeep.

@Attaboy55

Do read here about IBS and how, since it was Reset/Cleared, that it will take a period of time to relearn....

About IBS Reset/Clear:
https://www.jlwranglerforums.com/forum/threads/ibs-clear-reset.67955/

Yes, in regard to the negative impact of leaving the fob in the vehicle..

Also, many owner's do not realize that the JL is always in contact with the outside word so to speak... how else would UConnect be able to remote start a JL, pinpoint location of a JL, etc..

This ongoing contact with the sky so to speak, along with other parasitic draw, means the JL is constantly using 12v power.... even when the JL is turned off and parked for hours/days/weeks, etc..


.

 

[WranglerMan]

@Attaboy55 its pretty common that you don’t keep the fob in your Jeep, actually with all these newer vehicles it’s not recommended, you could however put the fob is a faraday bag but I just take mine in the house.

As far as parasitic draw you are correct but the JL honestly does not draw anymore power than any other new vehicle that has the same stock add ons but if you are going to leave your JL parked for days on end it’s best to just keep it on a charger that is sized correctly for both batteries.

The general rule of thumb for bulk charging is .20-.35% of the amp hour rating then after that a trickle charge is fine, these so called trickle chargers are only meant to be used after your batteries are 100% charged as they make up for the parasitic draw and natural drop in voltages but were never meant to “ charge” a battery just meant to “ maintain”

 

[Attaboy55]

I wanted to add some observations detailing my experience. I have a 2019 Jeep Wrangler. Lately I have not been driving the vehicle due to surgery ( about 1 1/2 weeks). Got in it today and ESS said in center display NOT READY CHARGING. Ok great so I charged both batteries separately, ( the big battery was charges without any cables attached , just terminals , and the small battery was charged using the cables only . Charged AGM at a rate of 3 amps. Buttoned back up , still illuminating the same display. Took it to jeep dealer and the fix was to unplug the IBS, ( intelligent battery sensor) located at battery terminal on main battery. Tech simply unplugged while the vehicle WAS RUNNING and it reset the display and has not come on again. I also wanted to advise , Jeeps have a few items on them that draw power even when the engine is off. Particularly I was leaving my key fob in the vehicle while home and in the garage . Well, the jeep was using it's brain to look for the fob and as such drawing amperage in doing so . I now keep the fob at least 10" from the jeep.

UPDATE : Problem persisted back to dealership....THIS TIME BOTH BATTERIES REPLACED...........no longer giving the "not ready battery charging display". HOWEVER i plan on putting 3 amp trickle in place and making sure FOB away from vehicle, and most importantly driving it more , which is why I bought the most iconic vehicle in history, albeit with a " few" bugs here and there......oh well

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