Auto Start-Stop Question

[bthomp]

Hey Bill:

I'm not here pushing or condemning ESS as a concept for saving fuel, or bashing Stellantis' design for that system: much as it could have been done much better.

Rather, I'm here to assign blame where I think it belongs, and that's with the EPA rules for ESS systems and stupid law suits.

The way the EPA regulates ESS incentivizes Stellantis to simply pass its ESS test with a new vehicle and to insure that those running ESS don't get stranded at a traffic light, hence the tiny battery on dual AGM battery Wranglers. For Stellantis to make the system more robust (say with equally sized batteries that swapped roles now and then) would cost us more and not gain any greater favor with the EPA; who if they (the EPA) were truly interested in (IMHO) writing law to insure ESS systems were designed better, would test that ESS systems still engaged well into ownership, not just when the batteries and vehicles were new.

As it regards the ESS system starting the engine with gear changes, particularly in Park, I heard it was an EPA requirement. If it isn't it might be what I'll call an Anton Yelchin requirement: something put in to prevent the law suits when people leave their ICE vehicles thinking they're powered down when in park, when they are instead they are just in an ESS event that will eventually terminate while the owner is "in the supermarket."

I'm not minimizing Yelchin's loss or good safety features. But the kind--speaking literally and in metaphors--that force companies to put warnings on coffee cups that say "warning, coffee is hot," IMHO are the product of overly sympathetic jurors willing to give stupid people money because they feel sorry for them and forget that we pay for those rewards in higher prices and a more nanny imposed lifestyle.

My $0.02, off soapbox.

I agree with your assessment.

Sponsored

 

[JJMalone]

Nope, push the button if you like.



Harm? LOL - ok, been into the "I hate ESS" sites and threads.

They've been stopping and starting gas engines in cars since the very first hybrids. No harm.
Technology isn't what it used to be, people base baseless "opinions" on what they read or relate back to decades ago.

It does no harm.

ESS is there to help Stellantis and other companies (for example, BMW, Mercedes, GM, Ford, etc.) get past CAFE/EPA regs. Without it, those companies pay crazy fines - or in the end, go under.

Jeep did not invent this and only adopted it after others created it and make it work.

All mechanical things have what we call a "service life". That is the number of times a starter, solenoid, flywheel ring gear can be cycled before they are worn out enough to become unreliable. Doubling the usage of these mechanical items means the service life will be used up in half the mileage/time. Is it incorrect to view that as doing harm?

Not to mention added complexity of software, switches, relays, wiring and a small troublesome battery just to satisfy government regulations. What minuscule savings/lower emissions is easily offset by making all those small batteries and hardware it takes for this system. I'd like to be rid of all that crap for the weight savings alone.

 

[AndySpill]

All mechanical things have what we call a "service life". That is the number of times a starter, solenoid, flywheel ring gear can be cycled before they are worn out enough to become unreliable. Doubling the usage of these mechanical items means the service life will be used up in half the mileage/time. Is it incorrect to view that as doing harm?

Not to mention added complexity of software, switches, relays, wiring and a small troublesome battery just to satisfy government regulations. What minuscule savings/lower emissions is easily offset by making all those small batteries and hardware it takes for this system. I'd like to be rid of all that crap for the weight savings alone.

Only time will tell if the carbon footprint used to create these carbon sequestering devices, and their impact on the ground they're buried in once used up will prove the lessor of the two evils of putting more CO2 into the air.

The theory is--not that I necessarily buy it--that forcing the marketplace in a particular direction incentivizes the creation of more advanced product that lasts better and, if properly regulated, causes less harm when more of it is recycled when used up, less of it is disposed of, and that disposed causes least harm to land.

There's more truth in this than I care to admit:

 

[JJMalone]

Only time will tell if the carbon footprint used to create these carbon sequestering devices, and their impact on the ground they're buried in once used up will prove the lessor of the two evils of putting more CO2 into the air.

The theory is--not that I necessarily buy it--that forcing the marketplace in a particular direction incentivizes the creation of more advanced product that lasts better and, if properly regulated, causes less harm when more of it is recycled when used up, less of it is disposed of, and that disposed causes least harm to land.

There's more truth in this than I care to admit:

The trace gas carbon dioxide is about .04% of the atmosphere. If it drops below .02% plant life dies. Wake up to the scam.

 

[Chupacabra]

The way the EPA regulates ESS incentivizes Stellantis to simply pass its ESS test with a new vehicle and to insure that those running ESS don't get stranded at a traffic light, hence the tiny battery on dual AGM battery Wranglers. For Stellantis to make the system more robust (say with equally sized batteries that swapped roles now and then) would cost us more and not gain any greater favor with the EPA; who if they (the EPA) were truly interested in (IMHO) writing law to insure ESS systems were designed better, would test that ESS systems still engaged well into ownership, not just when the batteries and vehicles were new.

So why is that every other manufacturer can make ESS work fine with a single battery? I've owned 3-4 different vehicles that all have ESS and they all work fine with a single battery. And before anyone says "It's because Jeeps go off-road and have winches and stuff", I'll counter with the new Ford Bronco also having ESS and a single battery.

Have a co-worker with a new Bronco and his ESS works perfectly all the time, with a single battery. 2 years in and it still works as designed for him. ESS on my Wrangler only works if I top off the batteries with my NOCO, and then it might work for 3-4 weeks before quitting again. ESS on Jeep vehicles is just so stupidly designed with this dual battery system.

 

[brent185]

I was shocked to find that ESS is also present with a manual transmission. It kills the engine when in neutral when the jeep is stopped. As soon as you engage the clutch it fires back up. For some reason this is way more annoying with a manual than an auto.

wonder if that hack will work for me….

 

[DHW]

I actually like my ESS, but I have a 2018 2.0T eTorque. I drove a 6cyl with ESS a while back and the difference is night and day. My ESS is smooth and close to unnoticeable. Not so with the 6cyl.

 

[rcadden]

Just wondering what is the harm that ESS does? I have a new 24 Sahara and have been using the ESS but if it causes problems down the road, I will rethink using it.

Thanks.

It does no actual harm to your Jeep. If it doesn't bother you, then don't sweat it, my friend.

Many here hate it because they hate anything that has to do with technology. They would prefer if they could buy a Jeep with a Rubicon suspension and Sport cab - as bare bones as possible.

Others here hate it because they believe that it adds unnecessary wear-and-tear to the engine, constantly starting and stopping all the time. I've yet to see any of them produce actual data proving this, likely because it doesn't exist.

There's value in everyone's opinions and beliefs, though. Same reason I change my oil every 5K miles even though in all reality it's probably fine to go 7.5K or even 10K with the proper filter/oil.

I ran mine with ESS for 2 years with no problems whatsoever. Only recently disabled it with a dongle because my AUX battery died (the battery that runs the ESS system) and it was cheaper to disable it than it was to replace the battery.

 

[Dabrakeman]

My concern with the 2.0L GDI engine is that it may increase oil dilution propensity.

 

[Shark01]

Hate it so much that I bought a 392

 

[VKSheridan]

ESS exists to appease idle reduction legislation. To get people to pay for the addition of hardware, it has been promoted as beneficial to fuel consumption which is technically true but not quite noticeably true. The break even costs are too distant from the fuel savings to remotely use that as an excuse but it’s there so we have to deal with it.

Every time your engine fires up from a stationary position, it is rotating parts lacking oil pressure. If someone is dumb enough to say decreasing the number of low engine oil pressure starts is bad, don’t let them work on your Jeep.

TLDR: Disabling ESS doesn’t hurt the engine, the Jeep or the wallet.

 

[AndySpill]

So why is that every other manufacturer can make ESS work fine with a single battery? I've owned 3-4 different vehicles that all have ESS and they all work fine with a single battery. And before anyone says "It's because Jeeps go off-road and have winches and stuff", I'll counter with the new Ford Bronco also having ESS and a single battery.

Have a co-worker with a new Bronco and his ESS works perfectly all the time, with a single battery. 2 years in and it still works as designed for him. ESS on my Wrangler only works if I top off the batteries with my NOCO, and then it might work for 3-4 weeks before quitting again. ESS on Jeep vehicles is just so stupidly designed with this dual battery system.

That's an enormously fair question John, really, no joke.

And I'm going to do my best to answer it with my theories, some you point out.

The Wrangler, unlike so many other vehicles that have ESS systems, (but yes, not unlike the Bronco) is quite unique in its owner's greater likelihood to not only customize it, but often with electrical current hungry appliances from stereo systems, to lights, to overlanding gear to winches.

Based on the location and size of the Aux battery, I have to think that it was an afterthought by the JL's engineers. One or more of them smartly reasoned that unlike in so many other vehicles, ESS couldn't be run on a Wrangler with one battery because the perfect storm of a cold night, a long traffic light, an ESS event, some aftermarket electrical current hungry appliance like roof lights, and an "about to be shot" battery could rob that one battery of enough electrical current, and fast enough, that by the time the vehicle early terminated an ESS event to crank the engine due to this battery voltage dropping too low, that that battery might lack ample cranking power to turn over the engine.

JL owners getting stranded at traffic lights with ESS events...boy would that hurt sales. So with good intentions the ideal of sparing the main battery during such ESS events, and running appliances off a second battery during ESS events appeared promising. At the ESS event's conclusion those 2 batteries could be brought back into parallel, with both energizing the engine crank.

No doubt, some well intentioned electrical engineers pointed out the trappings of running two dissimilar size batteries in parallel like what we have, but I'll bet the bean counters pushed back, pointing out how this properly designed ESS system for the Wrangler would increase purchase price for a feature that few would want to pay for.

Somewhere in the halls of Stellantis some exec probably said, in so many words "design the system to pass the dam EPA ESS test and insure that when ESS runs for the 'first 3 months of ownership,' nobody gets stranded. Those that want better battery systems: with our market share somebody in the aftermarket (Genesis Offroad) will devise a better system that those people can pay for. Those who want the ESS off button to be latching (i.e, remember its state from one cold crank to the next), something the EPA won't let us do: the aftermarket will provide that too."

As far as the Bronco is concerned, I suspect they learned from Stellantis' mistake here and decided to go with one battery given the limited aftermarket for Bronco specific stuff that might be available not only given the new/reintroduction of the vehicle, but the smaller aftermarket given its commensurate smaller market share compared to the Wrangler.....just a guess.

Maybe Stellantis could have designed their base Wrangler with one bigger battery. But every feature comes at a cost to consumers that only some are willing to pay for.

All these explanations justify Stellantis decisions. It's also entirely possible Stellantis execs got some of this wrong.

 

[Chupacabra]

That's an enormously fair question John, really, no joke.

And I'm going to do my best to answer it with my theories, some you point out.

The Wrangler, unlike so many other vehicles that have ESS systems, (but yes, not unlike the Bronco) is quite unique in its owner's greater likelihood to not only customize it, but often with electrical current hungry appliances from stereo systems, to lights, to overlanding gear to winches.

Jeep also puts this same stupid 2-battery solution into non-Wrangler products though too, such as the Cherokee. It makes no sense whatsoever to put it in that vehicle if the entire purpose is solely to support vehicles with tons of aftermarket electrical gee-gaws on it.

My co-worker has a bunch of add-on gizmos on his Bronco, has never had a problem with the battery or ESS on it even with just a single battery. I think it's just piss-poor engineering on Jeep's part to build the system this way. The number of complaints alone that Jeep must get about this crappy system has to far outweigh any benefit, along with all the warranty visits to fix something that cannot be fixed.

In fact, my co-worker who now has a Bronco got rid of his Cherokee specifically because the ESS never worked right in that vehicle either. It pissed him off enough to go to the dark side rather than buy a Wrangler.

 

[Chris2183]

JL owners getting stranded at traffic lights with ESS events...boy would that hurt sales. So with good intentions the ideal of sparing the main battery during such ESS events, and running appliances off a second battery during ESS events appeared promising. At the ESS event's conclusion those 2 batteries could be brought back into parallel, with both energizing the engine crank.

As someone who got stranded at a traffic light on 2 different occasions, I was told that Jeep's software at the time did not take into account if the main battery had enough amps to restart the engine or not.

This was eventually addressed in a software update that my local dealer wanted to charge me a diagnostic fee and additional labor to install. I declined and opted to just press the button every time until I sold the Jeep

 

[Mguy]

Every once in a while thread contributors and readers can benefit from a review summary of basic concepts. Here goes for those interested.

A critical vehicle system is the battery/charging setup for reliable starting and operation. That system should work in virtually all climates even for vehicles sitting for long periods with modest "parasitic" loads--three months for healthy a AGM battery should be expected.

Buffering of electrical loads while the engine/alternator is running is a secondary function easily satisfied by virtually any battery of minimal size and performance, and so is not further discussed here. Also, the diagnostic/predictive benefit that ESS provides for the electrical system in general, a side effect of allowing ESS to "work" before engine/charge shut off, is not further discussed.

There are burdens a battery/charging system must overcome to be successful. Vehicle use without charging is typically the heaviest. Using the "accessory" ignition setting while operating loads is an obvious example. ESS operation is another.

To be clear, ESS operation which shuts down the engine--meaning charging--while electrical loads continue is a burden on the battery/charging system.

Jeep attempted to satisfy this burden, in way too many JL Wranglers, by adding a second, "aux" battery, along with additional hardware and software. However, the attempted fix generally doesn't work, and sometimes results in electrical issues, primarily because the additional stuff is bad science. The dual battery system tries to charge dissimilar batteries as if they are one, and thus fails the particular charging needs of AGM type batteries. The final result is premature battery failure.

Dual battery JL owners will have their own views and opinions, and respond as they think right. Environmental, political, and social considerations aside, there are different ways to go. There's external charging, the aux battery/F42 disconnect (not really a "bypass" or a "delete"), and other options. But some things are always true. Whether or not an owner allows ESS to shut off charging, the stock dual battery/single charge system will almost certainly result in premature battery failure. And ESS charging shut off will almost certainly accelerate that failure. Let each owner make their decisions, fully informed.

Sponsored