Y.A. ESS Question

[AndySpill]

Y.A. stands for yet another.

And I'm sorry for that but the issue I'm about to report isn't one I've read about or can find with searching: which isn't to say it isn't in some post.

And sure, turning ESS off, disconnecting the Aux battery, yanking Fuse 42 and/or jumpering N1 and N2 in the PDC: probably what I should do but I live in a fool's paradise that assuages my guilt for driving this "gas guzzling anything but aerodynamic box on wheels" by doing my part to save gasoline at red traffic lights. I trickle charge with solar so at least the savings in gasoline isn't offset by that in the electric to run the trickle charger.

It's illogical, I know. I'm in Jeep therapy.

So I'm on a parkway that has lights. I've been doing a fair speed for a fair time with my trickle charged batteries and get to a known long red light. No climate control fan's running that might early terminate the ESS event I'm about to enter.

At some point during this long light the ESS event ends early, I guess the ESS battery voltage got too low, the two batteries are brought back into parallel and the engine cranks, but the EVIC turns ESS off, like there's a problem with it.

This typically goes away at the next cold crank. It only happens rarely.

Has anyone had this? Low ESS battery voltage during an ESS event is suppose to simply force an early engine crank without complaint, not generate a problem.

Thanks in advance.

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[mwilk012]

What actual message comes up?
How old is your aux battery and why isn't it new?

 

[AndySpill]

What actual message comes up?
How old is your aux battery and why isn't it new?

I think I get some message about servicing the ESS system at the same time the EVIC flashes the "ESS off" icon of a letter "A" with a circle around it followed by an exclamation point.

I'm not sure why you seem to be requiring my ESS battery to be new, although I could certain see your point if it was old. I replaced it and the main in January of 2022.

 

[mwilk012]

I think I get some message about servicing the ESS system at the same time the EVIC flashes the "ESS off" icon of a letter "A" with a circle around it followed by an exclamation point.

I'm not sure why you seem to be requiring my ESS battery to be new, although I could certain see your point if it was old. I replaced it and the main in January of 2022.

How quickly does voltage fall off when stopped during an ESS event and how low does it get? You should be able to sit for several minutes without it starting. I think you should pull the battery and test it.

What brand did you install?

 

[AndySpill]

How quickly does voltage fall off when stopped during an ESS event and how low does it get? You should be able to sit for several minutes without it starting. I think you should pull the battery and test it.

What brand did you install?

I have a load tester and will definitely take your advice and independently test the ESS battery. Thanks. I guess I really have no point of complaining about this if my ESS battery has seen better days. Fortunately the battery's cables, if not the battery itself, is easy to get to.

I honestly forget which one off of Rhinebeck's list of "ESS batteries that don't seem to really suck"--as opposed to ordinarily suck, I went with.

It's a really long light at a complex intersection that has to, while red, green light 2 or 3 other lights that cross railroad tracks, and ESS was on for over a minute, but only the radio was on above all other appliances beyond my control that tax the vehicle's electrical system.

 

[mwilk012]

If the batteries pass a load test, try to find the actual fault code that it’s setting. Honestly I’m not even sure which module would record the payout but I assume PCM or BCM.

 

[Rogersocal]

So, for those that know... On the E-torq the start is performed by the 48V battery right? I'm just making sure i understand the system correctly. The 12v Battery is just a "Keep alive"?

 

[Bandit59]

I think I get some message about servicing the ESS system at the same time the EVIC flashes the "ESS off" icon of a letter "A" with a circle around it followed by an exclamation point.

I'm not sure why you seem to be requiring my ESS battery to be new, although I could certain see your point if it was old. I replaced it and the main in January of 2022.

Well it is two years old. Falls in the window of an aged battery sadly I will bet on a weak battery sadly. And everything said should replace both at same time. As the bad battery will kill the other. You could replace the small battery and see what happens

 

[AndySpill]

Well it is two years old. Falls in the window of an aged battery sadly I will bet on a weak battery sadly. And everything said should replace both at same time. As the bad battery will kill the other. You could replace the small battery and see what happens

I very infrequently use this vehicle Mike but I invariably trickle charge both batteries when it's parked on my driveway, which is 98% of the time.

I'm curious as to how long people think the dual batteries should last. I thought 3 years at minimum.

 

[Bandit59]

I very infrequently use this vehicle Mike but I invariably trickle charge both batteries when it's parked on my driveway, which is 98% of the time.

I'm curious as to how long people think the dual batteries should last. I thought 3 years at minimum.

They should. But the little battery is known to go early. If you got Mopar batteries that’s what I think it is. My Mopar AGM battery in my Ram lasted 26 months. Warranty was 24 months. But I also have a 2020 Ram 50000 miles oringal Mopar battery. But many Jeeps have to replace every two years. And replace in pairs

 

[JLfromCA]

I very infrequently use this vehicle Mike but I invariably trickle charge both batteries when it's parked on my driveway, which is 98% of the time.

I'm curious as to how long people think the dual batteries should last. I thought 3 years at minimum.

My 19 Jeep was built late 2018. Still running both original battery‘s. However I did disable ESS the day I bought it. your results may vary.

 

[The Last Cowboy]

I live in a fool's paradise that assuages my guilt for driving this "gas guzzling anything but aerodynamic box on wheels" by doing my part to save gasoline at red traffic lights. I trickle charge with solar so at least the savings in gasoline isn't offset by that in the electric to run the trickle charger.

It's illogical, I know. I'm in Jeep therapy.

With so much self inflicted eco-guilt, why would you even drive a Jeep?

It's better to have a vehicle that you can rely on day in and day out, than to try to save a few ounces of fuel. What's worse is that the ESS dual battery system eats batteries at twice the rate of a system with one battery. So if the environment is your concern, take that in account.

Your best bet is to eliminate the auxiliary battery and replace the main with an H7/94R. The larger main battery will likely enable you to keep using the ESS function if you wish.

 

[The Last Cowboy]

So, for those that know... On the E-torq the start is performed by the 48V battery right? I'm just making sure i understand the system correctly. The 12v Battery is just a "Keep alive"?

Yes, all the restarts are done by the 48v BSG (Belt driven Starter Generator), which is also a light hybrid electric drive motor. Cold starts are done with the traditional starter.

 

[AndySpill]

With so much self inflicted eco-guilt, why would you even drive a Jeep?

..because I was being half comical but probably didn't make that clear, sorry.

It's better to have a vehicle that you can rely on day in and day out, than to try to save a few ounces of fuel. What's worse is that the ESS dual battery system eats batteriees at twice the rate of a system with one battery. So if the environment is your concerns, take that in account.

Excellent point. Disposing of batteries comes with its own green cost. And yeah, the dissimilar size batteries just aren't good.

Your best bet is to eliminate the auxiliary battery and replace the main with an H7/94R. The larger main battery will likely enable you to keep using the ESS function if you wish.

I don't like running ESS on one battery in a JL. Yes, most vehicles do, and it could be a top of the line workhorse of a battery. The problem is even top of the line workhorses get old and in the perfect storm of a cold night, and old once great battery, a long traffic light, appliances running, and a system designed for two batteries that may not be as responsive to battery voltage drops during ESS events as an ESS system designed with one battery, I'm concerned that by the time the dual AGM battery JL recognizes that its time to end the ESS event early due to voltage drop, that there's enough power in the battery to crank.

I think I would like a modified Genesis Offroad kit that simply replaces both stock batteries and randomly alternates which battery plays the role of the main and which the role of the ESS. I doubt Shane has the demand to construct that. Maybe when it's time to replace my batteries I'll buy Shane's tray and batteries to fit it, but not his full blown kit, and construct my own manual switches to periodically switch the roles of the two batteries.

 

[mwilk012]

The factory setup is perfectly fine imo. I'm sure I drive my Jeep even less than you do, it stays parked outside and never has been on a charger. ESS works perfectly 4 years after replacing the battery.

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