Jump starters: who’s got one and what’s good?

[_olllllllo_]

Hmmm... I get the ESS battery is for starting (cold start / traffic light) but not sure why the main battery would not come into play on a modern vehicle if the ESS batt was discharged. That could leave you stranded at a stop light etc. There are a couple of threads on this but here is one... https://www.jlwranglerforums.com/forum/threads/drained-battery-any-jumpstart-tips.12316/

Also, I love the videos on YTube by Project Farm. He really goes into detail on what works, won't does not and comparisons of cheap vs expensive tools, lubes, and electrical items. Specific to portable jump systems >

When we get back to the office after all this, I will have to take my JLU into our techs at the Toyota Campus to have them take a look and give some feedback...

Thanks for including that video. Now I have to send the Noco back to Amazon and get the Audew. I will go for the 2000Amp version. I really appreciate all the effort ProjectFarm puts into these tests and he is very thorough.

The most important question is which tartan?

Sponsored

 

[Medsker]

I have the ARB Jump Starter. I haven't had to use it yet. I bought it in Australia and I'm not sure if it's available in the states. At least I haven't seen it for sale over here.

Link

 

[Gee-pah]

@maddscot Bob and @Dkretden David:

I think a better understanding of how the 3.6L once upon a time cranked, cranks now, and charges while parked and connected to a power pack is in order.

Bob, let's tune this up a bit.

" I get the ESS battery is for starting (cold start / traffic light) but not sure why the main battery would not come into play on a modern vehicle if the ESS batt was discharged. That could leave you stranded at a stop light etc. "

• The ESS battery, it is true sir from forum member testing does participate in engine cranks, be they cold or ESS, but during cranks it is connected in parallel to the main, larger battery (so the main battery does most of the work.) Back in 2018 it was necessary for that ESS battery to have basic charge on its own, before the two batteries would be joined in parallel to both effect an engine crank: cold or post ESS.
• It is extremely unlikely that the ESS battery will lack adequate power to crank the rig after an ESS event because ESS won't engage unless the ESS battery's power meets a high threshold, and if while in ESS mode, that battery is drained too much the 3.6L will end the ESS event prematurely, before the brake pedal is released, put both batteries back into a parallel connection, crank the rig, and get the alternator back in the business of charging both batteries.

David wrote:

"my understanding is that it will jump a 2020 JLUR 3.6L even with a shot aux battery ..... supposedly the 2018’s and some 2019’s With a shot aux battery were “not jumpable“ with a small pack ... you had to use cables."

I think you are correct David, but let me again try to explain why I think this so.

Back in 2018, it is my belief that the owner's manual has you sit with energized jumper cables on the 3.6L before cranking because doing so charges both batteries (connected in parallel while the 3.6L is at rest.) The goal during this charging period was often (but not always) to put some juice in the ESS battery (much that you'd also charge the main battery) because prior to attempting the cold crank, that ESS battery would be examined by the rig in isolation, and if lacking sufficient power the crank would not be attempted. Never mind that an ESS battery which passes this test is then hooked up to the main battery in parallel, the latter suppling most of the crank energy, just prior to that crank.

This is why back in 2018 an Aux battery alone, charged adequately, could crank a rig, but not a main battery alone.

I think (I may be wrong) that it also explains why a lot of power packs didn't work well. They spent down some of their juice in this charging phase and may have not had enough for the crank.

~~~~~~~~~~~~~~

I think FCA borrowed the sequence for cold cranking from cranking after ESS events and it was IMHO stupid because unlike cold cranks, during ESS events the ESS battery is monitored, as mentioned, for loss of power during ESS, that if too much, ends ESS early so you don't get stranded. No such logic happens in cold cranks.

I'm not saying I changed this, but I, along with others, wrote the then President of FCA and said, "you need to download new instructions to the rig to cold crank even if the Aux battery is dead. Using the ESS crank algorithm on cold cranks is stupid."

Sure enough subsequent model year JL's seemed to not only start operating under this new cold crank logic, but Jerry, @Jebiruph who is very up on this stuff, noticed this cold crank logic change in his 2018 3.6 JL after a recent dealer flash of his rig.

https://www.jlwranglerforums.com/forum/threads/3-6l-ess-bad-aux-battery-no-start-firmware-fix.53608/

So--in practical sense what does this all mean?

Maybe the ESS battery is no longer tested in isolation upon cold crank, or if it is, such cold cranks are no longer contingent upon it having power. This *may* mean that keeping power packs connected for a while prior to cold cranking may not be necessary--at least for as long as the owner's manual suggests.

And this *may* mean that power packs don't get partially depleted effecting this charge and that some power packs which didn't crank a dead 3.6L before, may today succeed because of this cold crank logic change and their getting out of the "charging business" and into what they do best "the cranking business" (i.e. lots of juice for a short period of time.)

I hope that makes sense.

 

[Jebiruph]

@maddscot Bob and @Dkretden David:

I think a better understanding of how the 3.6L once upon a time cranked, cranks now, and charges while parked and connected to a power pack is in order.

Bob, let's tune this up a bit.

" I get the ESS battery is for starting (cold start / traffic light) but not sure why the main battery would not come into play on a modern vehicle if the ESS batt was discharged. That could leave you stranded at a stop light etc. "

• The ESS battery, it is true sir from forum member testing does participate in engine cranks, be they cold or ESS, but during cranks it is connected in parallel to the main, larger battery (so the main battery does most of the work.) Back in 2018 it was necessary for that ESS battery to have basic charge on its own, before the two batteries would be joined in parallel to both effect an engine crank: cold or post ESS.
• It is extremely unlikely that the ESS battery will lack adequate power to crank the rig after an ESS event because ESS won't engage unless the ESS battery's power meets a high threshold, and if while in ESS mode, that battery is drained too much the 3.6L will end the ESS event prematurely, before the brake pedal is released, put both batteries back into a parallel connection, crank the rig, and get the alternator back in the business of charging both batteries.

David wrote:

"my understanding is that it will jump a 2020 JLUR 3.6L even with a shot aux battery ..... supposedly the 2018’s and some 2019’s With a shot aux battery were “not jumpable“ with a small pack ... you had to use cables."

I think you are correct David, but let me again try to explain why I think this so.

Back in 2018, it is my belief that the owner's manual has you sit with energized jumper cables on the 3.6L before cranking because doing so charges both batteries (connected in parallel while the 3.6L is at rest.) The goal during this charging period was often (but not always) to put some juice in the ESS battery (much that you'd also charge the main battery) because prior to attempting the cold crank, that ESS battery would be examined by the rig in isolation, and if lacking sufficient power the crank would not be attempted. Never mind that an ESS battery which passes this test is then hooked up to the main battery in parallel, the latter suppling most of the crank energy, just prior to that crank.

This is why back in 2018 an Aux battery alone, charged adequately, could crank a rig, but not a main battery alone.

I think (I may be wrong) that it also explains why a lot of power packs didn't work well. They spent down some of their juice in this charging phase and may have not had enough for the crank.

~~~~~~~~~~~~~~

I think FCA borrowed the sequence for cold cranking from cranking after ESS events and it was IMHO stupid because unlike cold cranks, during ESS events the ESS battery is monitored, as mentioned, for loss of power during ESS, that if too much, ends ESS early so you don't get stranded. No such logic happens in cold cranks.

I'm not saying I changed this, but I, along with others, wrote the then President of FCA and said, "you need to download new instructions to the rig to cold crank even if the Aux battery is dead. Using the ESS crank algorithm on cold cranks is stupid."

Sure enough subsequent model year JL's seemed to not only start operating under this new cold crank logic, but Jerry, @Jebiruph who is very up on this stuff, noticed this cold crank logic change in his 2018 3.6 JL after a recent dealer flash of his rig.

https://www.jlwranglerforums.com/forum/threads/3-6l-ess-bad-aux-battery-no-start-firmware-fix.53608/

So--in practical sense what does this all mean?

Maybe the ESS battery is no longer tested in isolation upon cold crank, or if it is, such cold cranks are no longer contingent upon it having power. This *may* mean that keeping power packs connected for a while prior to cold cranking may not be necessary--at least for as long as the owner's manual suggests.

And this *may* mean that power packs don't get partially depleted effecting this charge and that some power packs which didn't crank a dead 3.6L before, may today succeed because of this cold crank logic change and their getting out of the "charging business" and into what they do best "the cranking business" (i.e. lots of juice for a short period of time.)

I hope that makes sense.

My observation is that with the updated firmware the ESS is still tested in isolation during a cold crank, the difference is if it fails it generates an error and the cold start is tried again with the test disabled. For subsequent cold starts, the ESS battery will not be tested until the error is cleared.

This typically will not have any affect on jump starting, you will still be jump starting/boosting two batteries connected in parallel.

 

[Gee-pah]

My observation is that with the updated firmware the ESS is still tested in isolation during a cold crank, the difference is if it fails it generates an error and the cold start is tried again with the test disabled. For subsequent cold starts, the ESS battery will not be tested until the error is cleared.

This typically will not have any affect on jump starting, you will still be jump starting/boosting two batteries connected in parallel.

Thanks Jerry, I have a question.

Do you believe the waiting period before attempting a cold crank, with energized booster cables connected to the main battery (connected, yes, to the ESS/Aux battery as well because the two batteries are connected in parallel at rest) before a jump start is at least in part about charging the ESS battery? If not, what do you believe the waiting period is for, at least on the 3.6L JL?

If you do believe it (was originally) about charging the ESS battery, it would seem under that which you've recently found with the recent firmware flash, that having the ESS battery charged at least somewhat no longer appears necessary to crank the engine, even if a second attempt, as you report, has to be made. On the second attempt the main battery, connected to the energized jumper cables in parallel would seem to act as one source of current to the starter, no?

Thoughts?

Thanks.

 

[Jebiruph]

Thanks Jerry, I have a question.

Do you believe the waiting period before attempting a cold crank, with energized booster cables connected to the main battery (connected, yes, to the ESS/Aux battery as well because the two batteries are connected in parallel at rest) before a jump start is at least in part about charging the ESS battery? If not, what do you believe the waiting period is for, at least on the 3.6L JL?

If you do believe it (was originally) about charging the ESS battery, it would seem under that which you've recently found with the recent firmware flash, that having the ESS battery charged at least somewhat no longer appears necessary to crank the engine, even if a second attempt, as you report, has to be made. On the second attempt the main battery, connected to the energized jumper cables in parallel would seem to act as one source of current to the starter, no?

Thoughts?

Thanks.

I expect that the only thing that changes with the firmware upgrade is the ESS/Aux battery test only runs once. This would not change any other aspect of starting or jump starting, both batteries are still in parallel and each would still have the same impact on starting or jump starting. Except with the old firmware, there is never an attempt to crank the starter if the ESS/Aux fails the test. With the new firmware, it will attempt to crank the starter with a bad ESS/Aux battery.

 

[Gee-pah]

I expect that the only thing that changes with the firmware upgrade is the ESS/Aux battery test only runs once. This would not change any other aspect of starting or jump starting, both batteries are still in parallel and each would still have the same impact on starting or jump starting. Except, with the old firmware, there is never an attempt to crank the starter if the ESS/Aux fails the test. With the new firmware, it will attempt to crank the starter with a bad ESS/Aux battery.

I appreciate this Jerry but I feel like we're dancing around the essence here. To restate:

If:

• The rig can now crank without an energized ESS/Aux battery, even if it takes a second cranking try, then:
  
• We might not have to sit with energized power cables: be they connected to another vehicle or to a power pack on the main battery's terminals for too long (or as long as back in 2018) waiting for the ESS/Aux battery, connected in parallel when the 3.6L JL is at rest, to the main battery, to charge, because......that ESS/Aux battery no longer needs to hold a minimum charge anymore for a crank to ultimately be attempted by the vehicle, thereby:
  
• At least in the case of a power pack, some of its energy might not partially be depleted while it's no longer in the business of this pre-crank charging step necessary in 2018, allowing most of the power pack's power to go instead into the 3.6L's crank, meaning:
  
• Perhaps power pack's that failed at cranking under the 2018 JL 3.6L start logic, where the ESS/Aux battery had to first reach a minimum charge threshold for the crank to even be attempted (successfully or not) might today succeed given there may be less of a need to wait before trying a crank, and with that shorter wait time, the power pack is less drained on charging the batteries, leaving more of its current for the crank.

Sure both batteries are charged in this pre-crank step, not just the ESS/Aux, but if they're both dead, the rig's second attempt to crank solely against the main battery that you describe, parallel connected to the power pack, might now succeed because the power pack has more juice in it (as per the above theory) than the same scenario in 2018.

The essence of my inquiry to you sir is that given this change in start logic you describe, where a power pack can now seem to do what it does best: provide lots of power in a short period of time to crank the rig, rather than perhaps also first being in the pre-crank battery charging business, does it too make sense to you that more fully charged power pack products that failed in the past with the 3.6L crank ***might*** succeed today because of the steps I describe above?

Thoughts? Again, thanks?

 

[Jebiruph]

I appreciate this Jerry but I feel like we're dancing around the essence here. To restate:

If:

• The rig can now crank without an energized ESS/Aux battery, even if it takes a second cranking try, then:
• We might not have to sit with energized power cables: be they connected to another vehicle or to a power pack on the main battery's terminals for too long (or as long as back in 2018) waiting for the ESS/Aux battery, connected in parallel when the 3.6L JL is at rest, to the main battery, to charge, because......that ESS/Aux battery no longer needs to hold a minimum charge anymore for a crank to ultimately be attempted by the vehicle, thereby:
• At least in the case of a power pack, some of its energy might not partially be depleted while it's no longer in the business of this pre-crank charging step necessary in 2018, allowing most of the power pack's power to go instead into the 3.6L's crank, meaning:
• Perhaps power pack's that failed at cranking under the 2018 JL 3.6L start logic, where the ESS/Aux battery had to first reach a minimum charge threshold for the crank to even be attempted (successfully or not) might today succeed given there may be less of a need to wait before trying a crank, and with that shorter wait time, the power pack is less drained on charging the batteries, leaving more of its current for the crank.

Sure both batteries are charged in this pre-crank step, not just the ESS/Aux, but if they're both dead, the rig's second attempt to crank solely against the main battery that you describe, parallel connected to the power pack, might now succeed because the power pack has more juice in it (as per the above theory) than the same scenario in 2018.

The essence of my inquiry to you sir is that given this change in start logic you describe, where a power pack can now seem to do what it does best: provide lots of power in a short period of time to crank the rig, rather than perhaps also first being in the pre-crank battery charging business, does it too make sense to you that more fully charged power pack products that failed in the past with the 3.6L crank ***might*** succeed today because of the steps I describe above?

Thoughts? Again, thanks?

It seems like you are assuming that if the ESS/Aux fails the test, it is electrically separated from the cranking process, I do not assume that.

 

[Gee-pah]

It seems like you are assuming that if the ESS/Aux fails the test, it is electrically separated from the cranking process, I do not assume that.

I'm not. The truth is that I just don't know what happens. But assume for argument sake that the ESS/Aux and main battery are, as has previously tested to be the case, connected in parallel at the point of cold crank, and energized jumper cables are connected to the main battery's posts (which of course is also a parallel connection) as per the Owner's Manual procedure. Further, just for giggles let's assume that not only the 3.6L JL ESS battery is dead, but so too the main one.

This said, it may be necessary for the donor energy source (e.g. another vehicle/power pack) to apply the most basic of charge to the batteries, but this minimal time period compared to Owner's Manual procedure, given the recently reported change to the cold crank algorithm that allows a crank attempt even if the ESS/Aux battery is dead, *may* allow little (less) drainage of a power pack during this shortened wait time, to allow its remaining (a hopefully larger amount of) energy to focus on the crank.

Towards this end, a fully charged power pack that could crank a JK, but fail in 2018 on a JL, *might* today be able to also crank a 3..6L JL. (I'm not suggesting the each rig has the same amperage requirements.)

I'm *theorizing* that jump starting a JL, as a result of this cold crank algorithm change, may allow the procedure for jump starting a 3.6L JL to look more like that which is done to jump start, say, a sedan.

Of course the proof is in testing. I'd love to hear of a 2018 3.6L JL owner whose power pack failed to crank the vehicle in the past, get the recent dealer flash you report, and find success with that same power pack today.

Thanks.

 

[Gee-pah]

You laugh @Rhinebeck01 with emoticon. That's fine. You're entitled to your opinion. Maybe you're even right. But step on up to the adult table and explain why you think or know the above to be false so we can all learn.

P.S. For the record, @Rhinebeck01 removed his emoticon response to the above after this post was made.

P.S.S. and then put it back. Why not use your words @Rhinebeck01 on why you think my theories laughable?

 

[Rhinebeck01]

@RussJeep1
@Rahneld
@Gee-pah

This power pack and the JL thing has been explained to you (singular) multiple times already.

Yes, it gets old and laughable over time. And then you @Rhinebeck01 , me....

Guess Jerry has more patience then I do. Sorry, I do not have the time and patience.. it's just easier to click on emoticon HaHa...

I encourage you to re-read past forum posts. All the info is there..

 

[Gee-pah]

@RussJeep1
@Rahneld
@Gee-pah

This power pack and the JL thing has been explained to you (singular) multiple times already.

Yes, it gets old and laughable over time. And then you @Rhinebeck01 , me....

Guess Jerry has more patience then I do. Sorry, I do not have the time and patience.. it's just easier to click on emoticon HaHa...

I encourage you to re-read past forum posts. All the info is there..

What has been explained to you as well is that I'm not the other forum members you claim me to be.

But of course lets assume I was all the people you claim and then some. Here's the part you seem to not get:

That which has been explained before about the 3.6L JL's start logic on this forum, correct at the time of its writing, appears to have changed recently, rendering it currently wrong and outdated.

And I source this from Jerry's @Jebiruph's observations about the change in cold crank logic in the 2018 3.6L and a recent flash (linked above) : who you seem to like--so go take this up with him if you want, not me.

Now, what's changed? Like Jerry I have the patience you lack so I'll try this on you again.

Ready? Please take notes: I'll try to keep it as simple as I can--that of course requires more words.

• It appears that cold cranking the 3.6L JL, including those from 2018 which have recently been flashed, has had its algorithm changed.
• No longer, it appears, as in 2018, does the ESS/Aux battery need to maintain basic threshold levels of charge for the 3.6L JL to attempt a crank (a crank, yes, energized by both batteries.) Now maybe it takes 2 crank tries as Jerry reports, but you can get the rig started if your main battery has adequate power. We're talking no jumper cables yet.
• And could the main battery be dead and the rig not crank no matter how many tries are attempted, possibly, say, previously depleting its energy trying to charge, say, a defective ESS/Aux battery it is hooked up to in parallel when the rig's at rest: sure?
  
  
  With me still?
  
  
• So, if the ESS/Aux battery no longer needs a basic charge for the 3.6L JL to crank, maybe a jumping power source does not need to sit on the main battery of a powered down rig, at least as long as in 2018, that main battery connected mind you in parallel to the ESS/Aux battery when powered down, and thus this power source charging both batteries.
  
  (If the power source is connected in parallel to the main battery, which it's suppose to be, and the main battery is connected in parallel to the ESS/Aux battery when the 3.6L JL is at rest, which it is, the power source is also connected in parallel to the ESS/Aux battery.)
  
  
• Tell me, @Rhinebeck01, why do you think the Owner's Manual expressly includes the need for this waiting period, despite the power strength of the donor battery? I'm asking you literally, not rhetorically?
  
  Well my educated guess was primarily to charge the ESS/Aux battery to a point where the 2018 3.6L JL would, prior to this flash change Jerry reports, attempt a crank. Is a waiting period still advised?..quite possibly: to both put some current in the main battery and/or let the alternator of a donor cranked vehicle charge the donor battery up somewhat prior to the crank attempt.
  
  
  With me still?
  
  
• So, a power pack that doesn't need to charge the ESS/Aux battery, now that the cold crank algorithm seems to have recently changed, is a power pack that can focus on overcoming the forces of inertia to get the starter going to crank the engine. This is the stuff of devices capable of delivering large amounts of current over short periods of time, like, I don't know, a power pack?! That same power pack *may* no longer deplete some of its current doing that it wasn't really designed to do: effect charge over durations of time given this crank logic change.
• And as a result of this, *some* power packs that may have just fallen short of having the current to crank a 2018 3.6L in 2018, might succeed today cranking a later model or a recently flashed 2018 with this algorithm change because some of their precious power won't be wasted in business of charging the batteries (as much.)
• Sure, some power packs never had or will have the power to cold crank a 3.6L JL. I never said or implied otherwise. Sure, a JL is not a sedan. I said that this algorithm change might make the JL jump start *more* like a sedan, not identical to one.

Now that's the argument. If you want to say you feel its wrong that's fine. Explain why though.

And explain how this was explained to ANYONE here before when the crank algorithm appears to recently have changed. What has been explained before, although correct at the time it was written, quite possibly has changed, making it wrong: all why you want me to reference that I already know.

And how is this relevant? A thread dealing with what power packs are good, like this one, includes as a bear minimum, what power packs work--which may (or may not) have changed do to this algorithm change by FCA. Fair?

If you feel that algorithm change irrelevant, if you feel that the ESS/Aux battery no longer requiring a basic charge for a crank to be attempted is irrelevant, speak up. Say why you feel differently so, again, we can all learn.

And consider the following: if you don't have the time or patience here that's fine, but also consider a choice you're free to make about not coming to the forum, reading, or replying, as if someone is forcing you to.

I find it laughable myself that you feel it's all been explained before when you may be the one ignorant to this recent cold crank algorithm change by FCA and its possible implications for jump starting the 3.6L, rendering such explanations you feel that I should source possibly outdated and now wrong.

And I find it laughable that you think I need a refresher course on this stuff when I wrote to FCA's President years ago not only citing the stupidity of their using the same algorithm to cold crank the 3.6L JL as they do a post ESS crank. I explained why, (let me know if you need the explanation again) and I explained how I thought it best to fix this. And sure enough that's exactly what FCA did.

Do I think I'm the one who solely caused this change to the cold crank algorithm? Of course not. I'm sure others voiced the same concerns.

So go kick the dog if you're frustrated, not me. Better, go kick yourself, the dog and I deserve better.

Continued laughter emoticons here will be viewed by me, more importantly others, in lieu of tangible explanations of why I'm wrong (which I could be) as pathetic. Better, complain about the long dumbed down explanation that had to be repeated to you all while you don't like repeating yourself.

Gees.

 

[Jebiruph]

I'm not. The truth is that I just don't know what happens. But assume for argument sake that the ESS/Aux and main battery are, as has previously tested to be the case, connected in parallel at the point of cold crank, and energized jumper cables are connected to the main battery's posts (which of course is also a parallel connection) as per the Owner's Manual procedure. Further, just for giggles let's assume that not only the 3.6L JL ESS battery is dead, but so too the main one.

This said, it may be necessary for the donor energy source (e.g. another vehicle/power pack) to apply the most basic of charge to the batteries, but this minimal time period compared to Owner's Manual procedure, given the recently reported change to the cold crank algorithm that allows a crank attempt even if the ESS/Aux battery is dead, *may* allow little (less) drainage of a power pack during this shortened wait time, to allow its remaining (a hopefully larger amount of) energy to focus on the crank.

Towards this end, a fully charged power pack that could crank a JK, but fail in 2018 on a JL, *might* today be able to also crank a 3..6L JL. (I'm not suggesting the each rig has the same amperage requirements.)

I'm *theorizing* that jump starting a JL, as a result of this cold crank algorithm change, may allow the procedure for jump starting a 3.6L JL to look more like that which is done to jump start, say, a sedan.

Of course the proof is in testing. I'd love to hear of a 2018 3.6L JL owner whose power pack failed to crank the vehicle in the past, get the recent dealer flash you report, and find success with that same power pack today.

Thanks.

I expect this update has been in place from the factory since MY2019. Are the owners of 2019 and 2020 JLs (and JTs) finding it takes less power to jump start?

 

[Gee-pah]

I expect this update has been in place from the factory since MY2019. Are the owners of 2019 and 2020 JLs (and JTs) finding it takes less power to jump start?

Noted: relatively recently reported to the forum (by you) but likely of older origin....

 

[Gee-pah]

I expect this update has been in place from the factory since MY2019. Are the owners of 2019 and 2020 JLs (and JTs) finding it takes less power to jump start?

...and are owners of either model year or a flashed with this change 2018 3.6L JL finding little need for the waiting period (at least beyond that of other non dual battery ESS vehicle jump starts) detailed in the owner's manual no longer necessary....

..or are less owner's with this upgrade needing a jump start simply because their ESS/Aux battery lacks sufficient power to overcome the pre-crank test.....

Questions for the ages....

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