Disconnecting aux battery- which cable?

[Geoarch]

the batteries are in parallel - connected together - when driving or if it's sitting, turned off.
So a charger will charge both, but if there's a great difference in the health of either battery, one may not get what it fully needs.
So if I'm doing any more than a maintenance charge, I do each individually.

Thanks. That's what I thought.

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[Puch]

I watched a auxiliary battery disconnect video that showed you can just disconnect the negative cable and pull the fuse to disable the auxiliary battery. Their cable setup was slightly different (older model).
Mine is a 21, which cable do I disconnect for the auxiliary battery?

I’m not 100% sure, but I believe if you disconnect the wrong one it won’t start?
In other words:
If you disconnect the main negative cable you get no start. Put it back on and disconnect the other one. It should start.

 

[TestMule]

My JT was built in August of 2021.

I went out to start it today and it was dead, dead, dead. The first suspect in my mind is the aux battery. So, I want to delete it from the circuit. I believe I need to disconnect the cable that is connected to the right hand terminal (as you are facing the front of the vehicle) and pull a fuse.

Which fuse should I pull? I think it's the same one as noted above but I'm not sure what all that mid-year change entailed.

Thanks for any insight. I'm gonna go pull the cable and see If I still have power.

 

[NortonJTSS]

Mine was built May 2021. I had to disconnect the one on the right and then reattach the left one

 

[NortonJTSS]

My JT was built in August of 2021.

I went out to start it today and it was dead, dead, dead. The first suspect in my mind is the aux battery. So, I want to delete it from the circuit. I believe I need to disconnect the cable that is connected to the right hand terminal (as you are facing the front of the vehicle) and pull a fuse.

Which fuse should I pull? I think it's the same one as noted above but I'm not sure what all that mid-year change entailed.

Thanks for any insight. I'm gonna go pull the cable and see If I still have power.

F42

 

[TestMule]

Thanks, guys. The cable connections for battery negative power and aux positive are on a single plate. I guess I am gonna have to cut that plate in half, then pound out the post in the plate so I can slip it over the battery connection. Weird setup. My JL was not setup like that having one ring terminal per cable and no connecting plate.

 

[ShadowsPapa]

Thanks, guys. The cable connections for battery negative power and aux positive are on a single plate. I guess I am gonna have to cut that plate in half, then pound out the post in the plate so I can slip it over the battery connection. Weird setup. My JL was not setup like that having one ring terminal per cable and no connecting plate.

????
No, the two cables going to the top of the IBS on the main battery are:
AUX GROUND
and
BATTERY to chassis ground.

Aux positive doesn't come up to the main battery negative at all. Aux positive goes to N1, not to the main battery.

Not sure what you are talking about, but there's nothing to cut or pound out regardless of year.

If you had a 2020, you'd simply remove the cable i have marked 2020 to remove the aux ground from the main battery and chassis.
In 2020, the cable in the right on the pic marked 2021 is what goes to the chassis ground in 2020.

If you have a 2021 (depending on month of build) then you would remove the cable marked 2020, then the cable marked 2021, and put the cable marked 2020 back on the IBS on the main battery negative because in 2021 and later that cable goes to the chassis.

You don't cut anything or pound out anything.

The arrow in the picture points to the IBS - ALWAYS charge through the top of the IBS, or the stud on top, and always connect load grounds to the stud on top of the IBS.
Don'tcharge directly to the negative battery post

I went out to start it today and it was dead, dead, dead. The first suspect in my mind is the aux battery.

Why? Because that's what the internet says, even though the main battery can go just as easily? It could as easily be the main/crank battery that went south. A lot of forum members here have had that happen, and the aux was still good.
I still don't get why the aux is always the suspect - just because that post years ago kept getting repeated over and over and in forum after forum.

 

[TestMule]

????
No, the two cables going to the top of the IBS on the main battery are:
AUX GROUND
and
BATTERY to chassis ground.

Aux positive doesn't come up to the main battery negative at all. Aux positive goes to N1, not to the main battery.

Not sure what you are talking about, but there's nothing to cut or pound out regardless of year.

If you had a 2020, you'd simply remove the cable i have marked 2020 to remove the aux ground from the main battery and chassis.
In 2020, the cable in the right on the pic marked 2021 is what goes to the chassis ground in 2020.

If you have a 2021 (depending on month of build) then you would remove the cable marked 2020, then the cable marked 2021, and put the cable marked 2020 back on the IBS on the main battery negative because in 2021 and later that cable goes to the chassis.

You don't cut anything or pound out anything.

The arrow in the picture points to the IBS - ALWAYS charge through the top of the IBS, or the stud on top, and always connect load grounds to the stud on top of the IBS.
Don'tcharge directly to the negative battery post.

So I have a JT built in August of 2021. The cable marked 2020 above is the one I will swap over to the right side. That post on the 2020 cable is press fit to the bottom of that plate that both cables attach to. That's what I was referring to as needing to pound or press out. If I don't, there is no open ring terminal in that plate to go over the other connection to the right.

 

[TestMule]

Well, I am gonna get some bigger tools and try to loosen that bolt on the left hand post. I see where it has been removed and the bare post is still there. The cable on the left side is then swapped over to the right side.

Time for some big boy tools...

 

[ShadowsPapa]

This is the IBS - it has a stud on it. You move the 2020 cable, which in your case is actually chassis ground, over to this stud after removing the cable that has the plate and stud on it -

In other words, there's still a stud to attach the ground cable to.
It's going to be tight............

 

[TestMule]

I appreciate the info posted in response to my issue.

The aux battery has been disconnected from the system, the negative cable has been taped up and fuse 42 has been pulled.

The main battery was toast. It took almost 4 hours to put a minimal charge in it and after one start the battery voltage dropped to 9.1 - 9.3 volts. No more starts for that battery!

Luckily, an acquaintance saw my FB post and pulled an almost new OEM battery out of his shop. He had kept it after he had done a dual battery upgrade to his JL.

Once I had installed the battery, the JT started right up. Battery voltage at idle was 14.2 - 14.4 volts and after shutting it down it was 12.8 - 12.9 with no issues starting up again. No CEL or battery malfunction lights on the dash, either!

Thanks again for the help and assistance.

 

[ShadowsPapa]

I appreciate the info posted in response to my issue.

The aux battery has been disconnected from the system, the negative cable has been taped up and fuse 42 has been pulled.

The main battery was toast. It took almost 4 hours to put a minimal charge in it and after one start the battery voltage dropped to 9.1 - 9.3 volts. No more starts for that battery!

Luckily, an acquaintance saw my FB post and pulled an almost new OEM battery out of his shop. He had kept it after he had done a dual battery upgrade to his JL.

Once I had installed the battery, the JT started right up. Battery voltage at idle was 14.2 - 14.4 volts and after shutting it down it was 12.8 - 12.9 with no issues starting up again. No CEL or battery malfunction lights on the dash, either!

Thanks again for the help and assistance.

People need to realize - it's not always the aux battery that goes first.

I am going to have to isolate my batteries, charge each and reset the IBS on it after witnessing two battery chargers sort of going goofy while charging.
My BatteryMinder 1500 (1.5 amps) ran hotter than normal, and after a few hours, flashed error.
My larger NAPA charger (made by Carlisle) at 10 amps said the voltage was at 13.2 but it was only 75% after running almost 24 hours. When I shut it down and restarted it, it said the batteries were 100%.
And after all of that, voltage stayed above 14.x all the while making several fairly long drives this AM.

So, time to charge each independently and see what's going on.
I know it's cold out, but it still.................
ironically, everything works perfectly, including ESS and in fact, the voltage stays quite high during an ESS stop event! It will stay in the upper 12s for a minute, and hasn't dropped below 12.2 volts before the light changes.
WEIRD - but then doing the independent battery charging and IBS resetting on my 2020 pretty much resolved issues with that one. 2 1/2 years, who knows.

 

[g2020]

I finally got around to doing this.

Important: Confirm negative battery cable layout before you begin. The instructions for model years after mid-2021 are provided at the end of this post

Auxiliary Battery Delete
Jeep Gladiator
Model Years 2020 to Mid-2021

Steps:

Socket or wrench size is shown in parentheses​

1. Detach neg cable assembly from main neg post (10 mm)
2. Cover main neg post with a dry rag to prevent sparks
3. Detach (thinner) aux neg cable from aux neg connector (1/2") on neg cable assembly
4. Set aux nut aside
5. Cover neg cable assembly with a glove
6. Wrap exposed metal end of aux neg cable in electrical tape
7. Fasten three cable ties to keep tape from unraveling
8. Disconnect IBS cable from IBS (Intelligent Battery Sensor) by pressing locking tab on side of plastic connector
9. Pull fuse F42 using yellow fuse puller provided in PDC
10. Label fuse and keep in vehicle: Fuse F42, PCR CTRL FEED (ESS)*, 10A
11. Remove glove
12. Refasten aux nut, WITHOUT aux neg cable, to aux neg connector (1/2")
13. Remove rag
14. Reattach neg cable assembly to main neg post (10 mm)
15. Bend aux neg cable back and use a cable tie to loosely fasten it to the main neg cable (bend but don't fold)
16. Reconnect IBS cable to IBS and confirm that plastic connector is locked

Notes:

• Instructions for model years after mid-2021 are provided at the end of this post
• There are more heat-resistant solutions available than electrical tape & standard cable ties
• Doing an aux batt delete does not disable ESS (Engine Stop/Start / Autostop); ESS thread posted by @Andy29847
• Considerations when disabling ESS/Autostop and/or doing aux batt delete
  • If ESS (AutoStop) is disabled, the auxiliary battery becomes unnecessary and actually increases the risk of electrical failure
  • If the auxiliary battery is deleted (disconnected or removed altogether), fuse 42 must be pulled and ESS should be disabled
    • If ESS is not disabled when doing aux batt delete, ESS will engage using the main battery and cause the main battery to wear out more quickly
• ESS is disabled on my vehicle
• Remote Start works fine
• I will remove the auxiliary battery the next time that I replace the main (storage) battery or remove the front right (passenger) wheel liner (splash shield)
• For model years 2020 to mid-2021, it is not necessary to remove the IBS (Intelligent Battery Sensor) nut, indicated by a yellow dot in the photo below
  • However, it will take up to a week for the IBS to relearn the charging pattern
  • If Battery Voltage on dash does not become variable (as expected) within one week, reset IBS again using these instructions
• I have yet to find a true 13 mm fastener on the Gladiator (I'm told there are some); each is 1/2"

Tools:

Protective eyewear & gloves​

Ratchet​

10 mm socket​

1/2" socket​

Dry rag​

Electrical tape (I happened to have wide electrical tape on hand, which works better)​

Scissors, for electrical tape​

Cable ties​

Fuse puller (yellow plastic fuse puller provided in PDC, or Power Distribution Center box containing fuses and relays)​

END RESULT, model years 2020 to mid-2021:

Physical Removal of Auxiliary Battery

Note: These steps do not need to be performed immediately; I plan to remove the auxiliary battery the next time I replace the main (storage) battery or remove the front right (passenger) wheel liner (splash shield)

• Detach both neg cable assembly (first) and pos cable assembly from main battery
• Cover both main battery posts with rags
• Detach (thinner) aux neg cable from aux neg connector on (main battery) neg cable assembly (this step should already be done and fuse F42 should already be pulled)
• Remove auxiliary battery
• Wrap exposed metal end of each aux cable (in aux battery bay) in electrical tape and fasten tape, with three cable ties on each end, to keep tape from unraveling
• If you plan to do any fording / traveling through high water, a best practice is to fish the aux positive cable topside
  • Fish the aux positive cable topside (pull positive cable up from aux battery bay)
  • While pulling up aux positive cable, make every effort not to tear insulation around cable
  • Use a sturdy cable tie to anchor the aux positive cable, fished up from below, to the pos cable next to the main battery (or a different anchor point away from metal)

Auxiliary Battery Delete
Jeep Gladiator
Model Years After Mid-2021

• The following instructions are based on a video of a 2022 Jeep Gladiator by FrewSlinger on YouTube (I added some steps, including steps 1 & 2, below)
  • Please disregard the winch cable in his video
• If your cable layout does not align with either photo in this post, please use a different guide

Steps:

Socket or wrench size is shown in parentheses​

1. Detach neg cable assembly from main neg post (10 mm)
2. Cover main neg post with a dry rag to prevent sparks
3. Detach (thicker) main neg cable from main neg connector (1/2") on neg cable assembly
4. Refasten main nut, WITHOUT main neg cable, to main neg connector (1/2")
5. Cover main neg cable with a glove
6. Detach (thinner) aux neg cable from aux neg connector (10 mm) on IBS (Intelligent Battery Sensor, which is part of neg cable assembly)
7. Set aux nut aside
8. Wrap exposed metal end of aux neg cable, including integrated bracket, in electrical tape
9. Fasten cable ties to keep tape from unraveling
10. Disconnect IBS cable from IBS (Intelligent Battery Sensor) by pressing locking tab on side of plastic connector
11. Pull fuse F42 using yellow fuse puller provided in PDC
12. Label fuse and keep in vehicle: Fuse F42, PCR CTRL FEED (ESS)*, 10A
13. Remove glove
14. Attach (thicker) main neg cable to (what was) aux neg connector (10 mm) on IBS
15. Remove rag
16. Reattach neg cable assembly to main neg post (10 mm)
17. Bend aux neg cable back and use a cable tie to loosely fasten it to the main neg cable (bend but don't fold)
18. Reconnect IBS cable to IBS and confirm that plastic connector is locked

Notes:

• See Notes and Tools after first section above

ORIGINAL cable layout, model years after mid-2021:

Image credit: The image above is a frame captured at 00:37 in the video by FrewSlinger on YouTube, with my comments added

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