3.6L Battery Availability

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Tommywear

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I bypassed the aux battery in my 2018 and used Tazer to keep ESS turned off ALWAYS. I was 100% happy with this for 44k miles. Side note, ESS still works fine on ONE battery if you like using it.

I just got a 2021 and have not bypassed the aux battery yet, but will when I install my audio system.
....I'd be worried, maybe overly so, that an ESS event might wear done the one cranking battery....
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rlong69

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....I'd be worried, maybe overly so, that an ESS event might wear done the one cranking battery....
The system will still monitor the health of the single battery and restart the vehicle prior to discharging the battery. Nothing to sweat there if you want to use your ESS. I personally LOATH it, but am admittedly OLD and set in my ways.
 
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Tommywear

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The system will still monitor the health of the single battery and restart the vehicle prior to discharging the battery. Nothing to sweat there if you want to use your ESS. I personally LOATH it, but am admittedly OLD and set in my ways.
While many vehicles run ESS with one battery Richard, as you know, Stellantis designed their JL models, with dual different sized batteries, to run ESS on two batteries.

Was this design choice only because JL owners tend to run more appliances than other vehicle operators or did Stellantis also push the limits of the ESS battery beyond what designers of one battery ESS systems might, knowing that as part of their design, a resting cranking battery lied “waiting in the wings” to get the engine cranked while its stopped driver, say, makes a quick left turn in an intersection after an ESS event?

I don't know. I haven't done the testing.

I agree Richard. Whatever is serving as your ESS battery is monitored at among other times, ESS events. It's the unknown-to-me threshold of when this monitoring might end an ESS event before the driver takes their foot off the brake that concerns me.

People who mod are fine with me, including those who disengage ESS with one battery setups.

But until I know more about these threshold metrics I can't get behind one battery ESS, on JLs with dual different sized battery designs, for fear of, for example, the driver getting T-boned in an accident as a result of a failed or delayed post ESS event crank that may arise in an aged/discharged dual purpose ESS/cranking battery.

It's entirely possible that testing would reveal me to be overly cautious here.
 

rlong69

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I totally understand your caution, but we will have to agree to disagree.

Based on living with my 2018 for 3.5 years both with and without the dual battery I am 100% sure you are more likely to be stranded retaining the dual battery than deleting. That crappy lawn mower battery is not reliable in the least and takes the main with it when it as it fails. (ask me how I know)

This particular ESS system leaves a lot to be desired from an engineering standpoint. I admit I hate them in general, but this is a bit beyond that. If you have not witnessed the absolutely bonkers behavior of a JL being started with a failed battery I can tell you it is astoundingly terrible. Electronics going absolutely wacko as it death spasms to a stall. This is the only vehicle I have ever had that would not continue to run once started due to a bad battery. The alternator is not allowed to keep it running.

You can trust the engineers vision if you want to, but it was a swing and a miss on this one.

I am no automotive engineer by any stretch, but I have worked as an automation engineer for 15 years or so now. I have some understanding of how this all works.
 

Rhinebeck01

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I totally understand your caution, but we will have to agree to disagree.

Based on living with my 2018 for 3.5 years both with and without the dual battery I am 100% sure you are more likely to be stranded retaining the dual battery than deleting. That crappy lawn mower battery is not reliable in the least and takes the main with it when it as it fails. (ask me how I know)

This particular ESS system leaves a lot to be desired from an engineering standpoint. I admit I hate them in general, but this is a bit beyond that. If you have not witnessed the absolutely bonkers behavior of a JL being started with a failed battery I can tell you it is astoundingly terrible. Electronics going absolutely wacko as it death spasms to a stall. This is the only vehicle I have ever had that would not continue to run once started due to a bad battery. The alternator is not allowed to keep it running.

You can trust the engineers vision if you want to, but it was a swing and a miss on this one.

I am no automotive engineer by any stretch, but I have worked as an automation engineer for 15 years or so now. I have some understanding of how this all works.

@rlong69

I do believe.... I was one of the first here or actually the first to install a fused N1 - N2 bypass jumper, disconnect the Aux Negative on the Main's, neg terminal and to do this full time.

@Jebiruph provided me with the jumper (Thanks to Jerry for that) and my journey running with just the Main, started there so to speak..... 8-)

I have been doing so for 3 yrs. and have accumulated about 50,000 mi. since I started doing same...

I have found no shortcomings doing this... Never an EVIC message, no depleted battery(s), ....no nothing so to speak... You would not know my JL is/has been running on just the Main...

With that said, I agree with you for the most part.... I agree with your comments.... but....

....BUT.. but I cannot at all agree, that if you are running with just the Main battery that it is wise / prudent or smart to use the vehicle's ESS feature....

Sure, use it on occasion/rarely use the ESS feature ......but no way, would I say as you say .... "Nothing to sweat there if you want to use your ESS ".

In closing... I'll say no more on this... but tell all to do your homework so to speak, before running with just the Main and continuing to use the ESS feature.... Sure, run with just the Main, but limit your ESS use and even better, just don't use it.. Use the button to turn off or buy an adjunct to do that deed for you automatically.

.
 
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Tommywear

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Based on living with my 2018 for 3.5 years both with and without the dual battery I am 100% sure you are more likely to be stranded retaining the dual battery than deleting.
Agreed Richard. But I think the term "stranded" needs to be clarified here. All sorts of "stranded" sucks, but the kind that happens when your JL can't crank in the middle of an intersection is worse IMHO than the type more likely I think to happen in your scenario, which is being safely parked, but unable to cold crank.

As a 2018 owner did you opt for the TSB that allows you to crank with either battery?

I also agree with you that the way the ESS was design left room for improvement. Tandem equally sized batteries, perhaps that switch off playing the role of main and ESS, for starters, might have been better.

It's poor design is one of the reasons I trickle charge.
 
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