Sponsored

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

TCogs1

Well-Known Member
First Name
Thomas
Joined
Jan 12, 2018
Threads
13
Messages
390
Reaction score
365
Location
Somis
Vehicle(s)
cj6
Too bad we can not get @JeepCares and FCA to provide a real FCA Jeep electrical engineer to explain in detail the use cases and design.. vs all of us re-engineering their design. What a waste of time.. Thanks Jeep.... arggg.. One boring weekend, I will intentionally drain both batteries and try your suggestions and report back my findings.. Better to have this happen in a controlled condition vs the trail.. meanwhile I carry a spare yellow top optima for jumps and winch back up.
Sponsored

 

Gee-pah

Banned
Banned
Banned
First Name
Andy
Joined
Nov 19, 2019
Threads
59
Messages
1,658
Reaction score
1,264
Location
SanFrancisco
Vehicle(s)
JL Wrangler
i have a 2019. Disconnect aux negative and jump main. You will throw a code which can be cleared with a obd11 reader and torque software.
Yes--this will prevent the ESS/Aux battery from being charged by a donor power source on a 3.6L JL, which may help preserve the power source--particularly if a power pack--from unnecessary drain, allowing more of its power to effect the crank.

Another method, which may allow less to no wait time, and not throw codes is to put the power pack's negative on a 3.6L JL's main battery's negative, and the power pack's positive on terminal N1 in the power distribution center (PDC).

The power distribution center is that black box in the engine bay closest to the passenger's seat near the hood. If you take the cover off, N1 is the terminal in it most forward and closest to the driver's side.

This direct connects you to the ESS/Aux battery. Any JL test of this ESS/Aux battery prior to crank then becomes a test of this battery, otherwise "sistered" to the donor power source. Hopefully this should allow the ESS/Aux battery to appear to the 3.6L JL computer to have sufficient power, where after a parallel to the main battery is (re)established, and the crank can use all 3 power sources (ESS/Aux battery, main battery, donor power source) to crank the engine.
 

Gee-pah

Banned
Banned
Banned
First Name
Andy
Joined
Nov 19, 2019
Threads
59
Messages
1,658
Reaction score
1,264
Location
SanFrancisco
Vehicle(s)
JL Wrangler
Too bad we can not get @JeepCares and FCA to provide a real FCA Jeep electrical engineer to explain in detail the use cases and design.. vs all of us re-engineering their design. What a waste of time.. Thanks Jeep.... arggg.. One boring weekend, I will intentionally drain both batteries and try your suggestions and report back my findings.. Better to have this happen in a controlled condition vs the trail.. meanwhile I carry a spare yellow top optima for jumps and winch back up.
Thomas, IMHO numerous reasons exist why @JeepCares and FCA won't talk about this, at least in the 3.6L JL, for which all discussion below applies to.

As far as JeepCares is concerned, IMHO it's a technical matter beyond the depth of their normal limits to answer a question. This is not to label the group stupid or uninformed. I imagine some pretty smart people on FCA vehicle workings staff this department, or are at least at their disposal for consultation. Rather, it's the kind of question that they would suggest you "take up with your dealer."

As far as some FCA engineer discussing this is concerned, I don't think think this is likely either, because honest discussion would force the admission of the fact that the originally designed cold crank of the JL (in 2018) was flawed.

This isn't to say that it's that hard to piece together what may have happened historically. The story starts with an post ESS event engine crank examined first.

Love it or hate it, ESS won't engage, among other criteria, if the ESS battery doesn't meet an adequate charge threshold. If it does, and ESS engages, the ESS battery is monitored for voltage drop during the ESS event while it supplies the electronic needs of the vehicle during the engine off event. If this voltage drops too much, the vehicle will crank before its operator takes their foot off the brake.

In this scenario there's never opportunity for the ESS battery to fail. The event would not have occurred if this battery lacked sufficient power, nor will the ESS event deplete the battery as a result of the event running too long , and draining the ESS battery.

The problem occurs in adopting this ESS event crank logic to cold cranks, initiated by the driver pressing the start button with the brake pressed--which is what FCA seemed to do in 2018. Not having to "reinvent the wheel" saves a manufacturer money, even if this "wheel" is flawed for cold cranks.

Like in the post ESS event crank, in cold cranks the ESS battery is first checked. But it's not like in cold cranks that something happens if this battery gets too low, like in ESS where the event would never happen or end early. By analogy, to use this start logic for cold cranks and insure the integrity of the vehicle, the parked vehicle would have to monitor the ESS battery on your driveway, and crank the vehicle all on its own if the ESS battery gets too low in power, to allow the alternator to charge it up.

FCA probably realized with owner complaints as the vehicle was rolled out in 2018 that it was stupid to use the same logic on ESS and cold cranks. It appears from forum member comments that FCA changed the start logic in model years 2019 and beyond to attempt a cold crank on a second try, with the main battery, if the ESS battery is dead, a not strand the vehicle as in the 2018.

As mentioned, there appears to be a flash https://www.jlwranglerforums.com/forum/threads/3-6l-ess-bad-aux-battery-no-start-firmware-fix.53608/ TSB 18-092-19 that 2018's can get to change their cold crank logic to be like model years 2019 and beyond.
 

TCogs1

Well-Known Member
First Name
Thomas
Joined
Jan 12, 2018
Threads
13
Messages
390
Reaction score
365
Location
Somis
Vehicle(s)
cj6
Thomas, IMHO numerous reasons exist why @JeepCares and FCA won't talk about this, at least in the 3.6L JL, for which all discussion below applies to.

As far as JeepCares is concerned, IMHO it's a technical matter beyond the depth of their normal limits to answer a question. This is not to label the group stupid or uninformed. I imagine some pretty smart people on FCA vehicle workings staff this department, or are at least at their disposal for consultation. Rather, it's the kind of question that they would suggest you "take up with your dealer."

As far as some FCA engineer discussing this is concerned, I don't think think this is likely either, because honest discussion would force the admission of the fact that the originally designed cold crank of the JL (in 2018) was flawed.

This isn't to say that it's that hard to piece together what may have happened historically. The story starts with an post ESS event engine crank examined first.

Love it or hate it, ESS won't engage, among other criteria, if the ESS battery doesn't meet an adequate charge threshold. If it does, and ESS engages, the ESS battery is monitored for voltage drop during the ESS event while it supplies the electronic needs of the vehicle during the engine off event. If this voltage drops too much, the vehicle will crank before its operator takes their foot off the brake.

In this scenario there's never opportunity for the ESS battery to fail. The event would not have occurred if this battery lacked sufficient power, nor will the ESS event deplete the battery as a result of the event running too long , and draining the ESS battery.

The problem occurs in adopting this ESS event crank logic to cold cranks, initiated by the driver pressing the start button with the brake pressed--which is what FCA seemed to do in 2018. Not having to "reinvent the wheel" saves a manufacturer money, even if this "wheel" is flawed for cold cranks.

Like in the post ESS event crank, in cold cranks the ESS battery is first checked. But it's not like in cold cranks that something happens if this battery gets too low, like in ESS where the event would never happen or end early. By analogy, to use this start logic for cold cranks and insure the integrity of the vehicle, the parked vehicle would have to monitor the ESS battery on your driveway, and crank the vehicle all on its own if the ESS battery gets too low in power, to allow the alternator to charge it up.

FCA probably realized with owner complaints as the vehicle was rolled out in 2018 that it was stupid to use the same logic on ESS and cold cranks. It appears from forum member comments that FCA changed the start logic in model years 2019 and beyond to attempt a cold crank on a second try, with the main battery, if the ESS battery is dead, a not strand the vehicle as in the 2018.

As mentioned, there appears to be a flash https://www.jlwranglerforums.com/forum/threads/3-6l-ess-bad-aux-battery-no-start-firmware-fix.53608/ TSB 18-092-19 that 2018's can get to change their cold crank logic to be like model years 2019 and beyond.
Well, I am not buying the rationale that FCA can not help, At Boeing we routinely talk to pilots and operations staff to ensure they feel supported and they have the information they (Airlines - DOD) can leverage every dimension of the platform they purchased. Dealers are not equipped to do this, as I have talked with many, they are not engineers. The battery isolation logic is still not defined in the wiring diagrams, largely because it is software defined. Looking forward to buying a beer and a steak to the first Jeep EE I talk to :)
 

Gee-pah

Banned
Banned
Banned
First Name
Andy
Joined
Nov 19, 2019
Threads
59
Messages
1,658
Reaction score
1,264
Location
SanFrancisco
Vehicle(s)
JL Wrangler
Well, I am not buying the rationale that FCA can not help, At Boeing we routinely talk to pilots and operations staff to ensure they feel supported and they have the information they (Airlines - DOD) can leverage every dimension of the platform they purchased. Dealers are not equipped to do this, as I have talked with many, they are not engineers. The battery isolation logic is still not defined in the wiring diagrams, largely because it is software defined. Looking forward to buying a beer and a steak to the first Jeep EE I talk to :)
Oh--Thomas, I get that FCA can help...they should help.

They won't help. And I agree, dealers can't help. At best they put in a ticket with FCA, which gets elevated once, maybe twice to an engineer, who tells them the real deal.

I completely get what your saying about customer support at Boeing. Company to company levels of customer support are sometimes much better, for example the GE answer line. Utilities that use GE nuclear reactors can't exactly wait for a return call sometimes. This tends to be the case when enormously expensive assets, people's lives, and a purchaser country's military needs answers.

Customer service for FCA is a necessary costly evil. It happens at the cheapest levels it can so as to not disenfranchise enough customers that it affects sales greater than the cost to fund customer service.

And sadly (and fairly) this isn't exclusive to FCA.

You are absolutely right that no wiring diagrams https://www.jlwranglerforums.com/fo...one-and-what’s-good.51894/page-5#post-1275857 are going to indicate things like when software breaks connections for an instant to test components in isolation like the ESS battery and what it does based on the findings of these tests.
 

Sponsored

Jebiruph

Well-Known Member
First Name
Jerry
Joined
Feb 18, 2018
Threads
56
Messages
2,133
Reaction score
2,711
Location
Iowa
Vehicle(s)
2018 JLU, 2019 KL, 2020 JT
Yes--this will prevent the ESS/Aux battery from being charged by a donor power source on a 3.6L JL, which may help preserve the power source--particularly if a power pack--from unnecessary drain, allowing more of its power to effect the crank.

Another method, which may allow less to no wait time, and not throw codes is to put the power pack's negative on a 3.6L JL's main battery's negative, and the power pack's positive on terminal N1 in the power distribution center (PDC).

The power distribution center is that black box in the engine bay closest to the passenger's seat near the hood. If you take the cover off, N1 is the terminal in it most forward and closest to the driver's side.

This direct connects you to the ESS/Aux battery. Any JL test of this ESS/Aux battery prior to crank then becomes a test of this battery, otherwise "sistered" to the donor power source. Hopefully this should allow the ESS/Aux battery to appear to the 3.6L JL computer to have sufficient power, where after a parallel to the main battery is (re)established, and the crank can use all 3 power sources (ESS/Aux battery, main battery, donor power source) to crank the engine.
This is from the owners manual of my Gladiator
Jeep Wrangler JL Jump starters: who’s got one and what’s good? aux jumpstart warnin
 

Gee-pah

Banned
Banned
Banned
First Name
Andy
Joined
Nov 19, 2019
Threads
59
Messages
1,658
Reaction score
1,264
Location
SanFrancisco
Vehicle(s)
JL Wrangler
This is from the owners manual of my Gladiator
aux jumpstart warning.jpg
Thanks for this heads up. A couple of things about this warning though.

This verbiage is not in the 2018 owner's manual for the JL.

And although you did retrieve it from a Gladiator manual I checked, and its verbiage is found in the 2019, 2020, and 2021 model year's JL manual, where I believe the cold crank logic, at least on the 3.6L engine, has changed (as discussed prior) to allow either battery to crank the rig. Perhaps this warning and the changed cold crank logic are integrally related.

I source my findings from here, where any model year owner's manual seems to be retrievable:

https://www.mopar.com/en-us/my-vehicle/owners-manual.html

The techniques I describe above about going to the ESS/Aux battery directly only make sense on a 2018 3.6L (without the previously mentioned flash) that seems to get it to cold crank like model years 2019 and beyond.

I assume that your Gladiator, as you know not available at the same time as the JL was introduced, mimics the newer cold crank logic. Perhaps you know this for fact.

:)
 

Jebiruph

Well-Known Member
First Name
Jerry
Joined
Feb 18, 2018
Threads
56
Messages
2,133
Reaction score
2,711
Location
Iowa
Vehicle(s)
2018 JLU, 2019 KL, 2020 JT
Thanks for this heads up. A couple of things about this warning though.

This verbiage is not in the 2018 owner's manual for the JL.

And although you did retrieve it from a Gladiator manual I checked, and its verbiage is found in the 2019, 2020, and 2021 model year's JL manual, where I believe the cold crank logic, at least on the 3.6L engine, has changed (as discussed prior) to allow either battery to crank the rig. Perhaps this warning and the changed cold crank logic are integrally related.

I source my findings from here, where any model year owner's manual seems to be retrievable:

https://www.mopar.com/en-us/my-vehicle/owners-manual.html

The techniques I describe above about going to the ESS/Aux battery directly only make sense on a 2018 3.6L (without the previously mentioned flash) that seems to get it to cold crank like model years 2019 and beyond.

I assume that your Gladiator, as you know not available at the same time as the JL was introduced, mimics the newer cold crank logic. Perhaps you know this for fact.

:)
The reason the warning is not in the 2018 manual is because it never occurred to them that people would actually try to do it. The impacted electrical systems were not changed since 2018, only the firmware.
 

Gee-pah

Banned
Banned
Banned
First Name
Andy
Joined
Nov 19, 2019
Threads
59
Messages
1,658
Reaction score
1,264
Location
SanFrancisco
Vehicle(s)
JL Wrangler
The reason the warning is not in the 2018 manual is because it never occurred to them that people would actually try to do it. The impacted electrical systems were not changed since 2018, only the firmware.
ok...perhaps yes to both.

Here's another perhaps. An owner is stranded overlanding with a 2018 3.6L with dead batteries in the middle of nowhere with a flimsy power pack.

Do they stick that power power pack's clips on to the main battery's terminals as per the manual, while it proceeds to deplete itself charging both batteries, when only the smaller, less demanding of charge, ESS/Aux battery is needed to effect the crank, and then try that crank, which likely fails because the power pack, never really designed for charging, but cranking, has all but exhausted itself on the aforementioned charge of both batteries, one battery unnecessarily?

Or do they direct connect that power pack to the ESS/Aux battery, wait minimal time for the ESS/Aux battery to develop some basic charge, (just like in our proverbial "father's Oldsmobile") not depleting that power pack with more extended charges to otherwise both batteries, and then attempt the crank knowing that when the rig tests the ESS/Aux battery for power prior to the crank, what the rig is seeing is the power of both the ESS/Aux battery and the power pack "sistered" together in parallel to form a composite voltage?

In the second scenario the wait period is less and the power pack is only depleted charging one battery (i.e. less depleted), increasing the likelihood of a successful crank.

As you know, the rig can crank with an adequately charged ESS/Aux battery all on its on. In model year 2018, without the aforementioned flash, the converse (cranking by the main battery alone) is not possible---short of your N1-N2 hack Jerry, which impressively works because it connects the two batteries in parallel at all times--even the two times the batteries are separated: 1) pre crank ESS/Aux battery test and 2) ESS events.

Certainly I would think the owner's manual warning you've provided, in addition to the changed logic where the 3.6L CAN now start with the main battery alone would absolutely find me agreeing with you that for all 3.6L 2018's with the flash, and all 3.6L JL model year's thereafter, connecting to the main batteries terminals is the best play.

And even in unflashed 2018 3.6L's which can connect to a donor cranked vehicle, whose alternator can replenish the donor battery as it charges both batteries of the stranded JL during this wait period stipulated in the owner's manual, connecting to the main battery is the proper play.

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

I'm actually glad this came up because it segues me into asking you about your opinions on the following.

I am of the belief, perhaps incorrect, as I haven't tested it (I'm not going to experiment on my rig) that power packs to crank the 3.6L JL need to be as substantial as they are NOT so much because of the power demands of the crank--although certainly not minimal, but because of this waiting period the owner's manual calls for while the 3.6L JL's batteries are charged and self-contained power packs are somewhat depleted in this process.

Although basic jump starting calls for waiting period, likely to put basic charge in the dead battery, in the 3.6L JL that donor power source, unlike in "our dad's Oldsmobile" isolates the donor power source from the ESS/Aux battery when that ESS/Aux battery is tested for power pre- crank (because the donor is connected to the main battery which is for a second disconnected from the ESS/Aux battery for this test.) The ESS/Aux battery must all in its own (not sistered to a donor battery in parallel) demonstrate enough power to pass this test.

Accordingly I am of the belief that this waiting period written into the 2018 manual had far more to do--without the owner's manual so much as saying so, with the need to charge the ESS/Aux battery given the logic design of the crank requiring basic power to the ESS/Aux battery before the crank would proceed.

I hypothesize with the flash to the 2018, or model years thereafter, where either battery can crank the rig, that this waiting period isn't nearly as essential, and that jump starting a 3.6L JL begins to look a lot more similar to the jump starting of any old basic sedan. I feel this way because if the ESS/Aux battery fails the pre-crank test under this new logic design, the rig in no longer stranded like in 2018, but the main battery is called upon to effect the crank, sistered in parallel to the donor battery like "our father's Oldsmobile."

Sure the waiting period guidance remains in 2019 and beyond manuals. But I suspect in model years 2019 on beyond its rationale is more akin to being identical to why this guidance exists in the owner's manual of any old sedan, and not for the complexity of the ESS system in the 3.6L JL as found particularly in an unflashed 2018.

Thoughts?
 

Jebiruph

Well-Known Member
First Name
Jerry
Joined
Feb 18, 2018
Threads
56
Messages
2,133
Reaction score
2,711
Location
Iowa
Vehicle(s)
2018 JLU, 2019 KL, 2020 JT
ok...perhaps yes to both.

Here's another perhaps. An owner is stranded overlanding with a 2018 3.6L with dead batteries in the middle of nowhere with a flimsy power pack.

Do they stick that power power pack's clips on to the main battery's terminals as per the manual, while it proceeds to deplete itself charging both batteries, when only the smaller, less demanding of charge, ESS/Aux battery is needed to effect the crank, and then try that crank, which likely fails because the power pack, never really designed for charging, but cranking, has all but exhausted itself on the aforementioned charge of both batteries, one battery unnecessarily?

Or do they direct connect that power pack to the ESS/Aux battery, wait minimal time for the ESS/Aux battery to develop some basic charge, (just like in our proverbial "father's Oldsmobile") not depleting that power pack with more extended charges to otherwise both batteries, and then attempt the crank knowing that when the rig tests the ESS/Aux battery for power prior to the crank, what the rig is seeing is the power of both the ESS/Aux battery and the power pack "sistered" together in parallel to form a composite voltage?

In the second scenario the wait period is less and the power pack is only depleted charging one battery (i.e. less depleted), increasing the likelihood of a successful crank.

As you know, the rig can crank with an adequately charged ESS/Aux battery all on its on. In model year 2018, without the aforementioned flash, the converse (cranking by the main battery alone) is not possible---short of your N1-N2 hack Jerry, which impressively works because it connects the two batteries in parallel at all times--even the two times the batteries are separated: 1) pre crank ESS/Aux battery test and 2) ESS events.

Certainly I would think the owner's manual warning you've provided, in addition to the changed logic where the 3.6L CAN now start with the main battery alone would absolutely find me agreeing with you that for all 3.6L 2018's with the flash, and all 3.6L JL model year's thereafter, connecting to the main batteries terminals is the best play.

And even in unflashed 2018 3.6L's which can connect to a donor cranked vehicle, whose alternator can replenish the donor battery as it charges both batteries of the stranded JL during this wait period stipulated in the owner's manual, connecting to the main battery is the proper play.

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

I'm actually glad this came up because it segues me into asking you about your opinions on the following.

I am of the belief, perhaps incorrect, as I haven't tested it (I'm not going to experiment on my rig) that power packs to crank the 3.6L JL need to be as substantial as they are NOT so much because of the power demands of the crank--although certainly not minimal, but because of this waiting period the owner's manual calls for while the 3.6L JL's batteries are charged and self-contained power packs are somewhat depleted in this process.

Although basic jump starting calls for waiting period, likely to put basic charge in the dead battery, in the 3.6L JL that donor power source, unlike in "our dad's Oldsmobile" isolates the donor power source from the ESS/Aux battery when that ESS/Aux battery is tested for power pre- crank (because the donor is connected to the main battery which is for a second disconnected from the ESS/Aux battery for this test.) The ESS/Aux battery must all in its own (not sistered to a donor battery in parallel) demonstrate enough power to pass this test.

Accordingly I am of the belief that this waiting period written into the 2018 manual had far more to do--without the owner's manual so much as saying so, with the need to charge the ESS/Aux battery given the logic design of the crank requiring basic power to the ESS/Aux battery before the crank would proceed.

I hypothesize with the flash to the 2018, or model years thereafter, where either battery can crank the rig, that this waiting period isn't nearly as essential, and that jump starting a 3.6L JL begins to look a lot more similar to the jump starting of any old basic sedan. I feel this way because if the ESS/Aux battery fails the pre-crank test under this new logic design, the rig in no longer stranded like in 2018, but the main battery is called upon to effect the crank, sistered in parallel to the donor battery like "our father's Oldsmobile."

Sure the waiting period guidance remains in 2019 and beyond manuals. But I suspect in model years 2019 on beyond its rationale is more akin to being identical to why this guidance exists in the owner's manual of any old sedan, and not for the complexity of the ESS system in the 3.6L JL as found particularly in an unflashed 2018.

Thoughts?
A firmware update does not change any of the physical characteristics of the batteries or the wiring. From my observation, all the update does is change the testing of a bad aux battery to a single test instead of constantly retesting a bad aux battery. With the wiring and batteries unchanged, jump starting and booster starting should be unchanged.

In my experience, jumpstarting a severely depleted battery has always required having the cables connected for an amount of time before a successful jumpstart. This is not unique to the JL.
 

Sponsored

sobediny

New Member
First Name
K
Joined
Dec 24, 2019
Threads
1
Messages
3
Reaction score
2
Location
ca
Vehicle(s)
2018 Wrangler
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...
Not a crazy Hot deal but it seems a good steal for 30% off for $64.99 now if anyone looking for Audew Jumper from audew directly.

https://m.audew.com/Audew-20000mAh-Peak-2000A-Car-Jump-Starter-for-Any-Gas-Engine-or-Up-To-8-5L-Diesel-Engine-with-LCD-Power-Display-p-100058.html
 

Rhinebeck01

Well-Known Member
Joined
May 9, 2018
Threads
155
Messages
11,875
Reaction score
17,119
Location
Multiple places..
Vehicle(s)
'18 JL Rubi, '22 Prevost M H3-45,'01 Harley FatBoy
Most JL/JLU owner's with dual batteries do not know how to separate out the batteries so a power pack can actually do the job..

Soooooo, kinda a bust to carry a power pack.. Best best for most is to to just carry decent jumper cables.

For pretty much a sure thing in regard to jumping starting a JL, just hook up the JL with the depleted battery(s) to a 12v donor vehicle, with quality (not el cheapo jumper cables) jumper cables and have the donor vehicle's engine running.

Now, leave the JL and donor hooked up to the running 12v donor, like that for 10-15 min., and then try to start/ start the JL.

More often then not, the JL will start with this method...

With battery power pack your chances are say 1 in 10 that the power pack will do the job.

Note: I'm not saying no one ever has been able to start a JL with a top notch battery pack but again, not all that often doing so is successful.
 

txj2go

Well-Known Member
Joined
Apr 7, 2020
Threads
34
Messages
1,219
Reaction score
1,244
Location
DFW
Vehicle(s)
CTS-V, 2018 JLU Sport Firecracker Red
Most JL/JLU owner's with dual batteries
I don't have dual batteries but I haven't had an opportunity to need to try a jump starter yet, and I'm not going to intentionally run down the main battery just for this test. I do carry jumper cables but the reason to use a jump pack, especially for me, is if I get out in a remote area and somehow run the battery down with no hope of a donor vehicle or cell service within miles.
 

Rhinebeck01

Well-Known Member
Joined
May 9, 2018
Threads
155
Messages
11,875
Reaction score
17,119
Location
Multiple places..
Vehicle(s)
'18 JL Rubi, '22 Prevost M H3-45,'01 Harley FatBoy
I don't have dual batteries but I haven't had an opportunity to need to try a jump starter yet, and I'm not going to intentionally run down the main battery just for this test. I do carry jumper cables but the reason to use a jump pack, especially for me, is if I get out in a remote area and somehow run the battery down with no hope of a donor vehicle or cell service within miles.
@txj2go

AND... and for guys/gals like you that do visit remote areas it is imperative that you take the time to do your homework and learn about the stock dual battery system ..... learn how to separate out the batteries.... and also DO, carry a spare/the correct for your JL, Z Case High Amp Fuse Array (know where it resides and how to install) along with a decent jump pack.

Specifics in regard to all of the above are readily available on the forum...
Sponsored

 
 



Top