Main battery and Aux Battery replacement write up

[Mr._Bill]

This reply is a bit off of the post but....I deleted the Mopar Aux battery and pulled the fuse 42. But I still get the Stop/Start failure warning and the '(A)! light. Is the 'fix' immediate or does it take some time?

That indicates an issue with the Main Battery. Pulling the F42 fuse causes the startup test to be done on the Main Battery instead of the Aux Battery.

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[Lost1wing]

This reply is a bit off of the post but....I deleted the Mopar Aux battery and pulled the fuse 42. But I still get the Stop/Start failure warning and the '(A)! light. Is the 'fix' immediate or does it take some time?

If your main battery was the issue, removing the aux did nothing for you. What you could try now is, charging the main with an AGM charger and reset the IBS.

Assuming you did the Aux delete correctly and didn't trash the fuse array, if charging doesn't work you might need to have your main tested or replaced.

 

[McRuss]

Well, maybe....but there was no issues with either battery prior to removing the aux battery. I did it because I could and I did not like the idea of a 'hidden' battery that could go bad some day. The main battery has been fine and continued to act fine today. No other indications of a problem.
I guess I did the delete the 'correct way' by disconnecting the cables and insulating them. I went through the wheel well and did not disturb the fuse block.

 

[Mr._Bill]

Well, maybe....but there was no issues with either battery prior to removing the aux battery. I did it because I could and I did not like the idea of a 'hidden' battery that could go bad some day. The main battery has been fine and continued to act fine today. No other indications of a problem.
I guess I did the delete the 'correct way' by disconnecting the cables and insulating them. I went through the wheel well and did not disturb the fuse block.

The high current fuse array is on the side of the fuse box. The batteries are paralleled, so the positive cable is always hot. If it touched anything metal while removing the Aux Battery, you blew a fuse in the high current array and it will need replaced (about $65).

 

[Lost1wing]

Well, maybe....but there was no issues with either battery prior to removing the aux battery. I did it because I could and I did not like the idea of a 'hidden' battery that could go bad some day. The main battery has been fine and continued to act fine today. No other indications of a problem.
I guess I did the delete the 'correct way' by disconnecting the cables and insulating them. I went through the wheel well and did not disturb the fuse block.

Only the Aux negative is removed and isolated in conjunction with removing f42. If you removed and isolated the Aux positive cables, you would need to bring the cables up to the main positive or install a jumper to power N1.

 

[jebiruph]

This reply is a bit off of the post but....I deleted the Mopar Aux battery and pulled the fuse 42. But I still get the Stop/Start failure warning and the '(A)! light. Is the 'fix' immediate or does it take some time?

Well, maybe....but there was no issues with either battery prior to removing the aux battery. I did it because I could and I did not like the idea of a 'hidden' battery that could go bad some day. The main battery has been fine and continued to act fine today. No other indications of a problem.
I guess I did the delete the 'correct way' by disconnecting the cables and insulating them. I went through the wheel well and did not disturb the fuse block.

I have occasionally triggered the (A)! while working with the batteries and had to disconnect/reconnect the battery(s) to reset it.

The aux battery delete will still work if the aux battery is removed and the cables are left in the battery box. F42 still needs to be removed to prevent the (A)! error.

 

[Mud Pie]

Okay, maybe I'm showing my age, but I'm of the mindset of that "it came with it, so suck it up buttercup". Do I like having two batteries ? Not at all, I think the whole Start/Stop thing is stupid as hell. But the vehicle is designed around it; hardware AND software, it is what it is.

As I was recently replacing both batteries (I went through the top and it really wasn't that bad), I kept repeating "stupid crap to do to replace freaking batteries". But I sucked it up. If it was something I had to do monthly, yeah, I'd try to find a "cure". But once every 3-4 YEARS ? I'll leave it factory, thank you very much. Disconnecting cables, pulling fuses, etc. is the ultimate in "Band-Aid repairs"; you didn't "fix" squat, you're fooling not only the Jeep, but yourself. Start/Stop is still there, trying to run the program loaded.

The ONLY true fix would be a complete software re-write, not a plug in gizmo, not a disable hack via OBD, not taping off terminals, but a complete Operating System re-write to remove the Start/Stop programming entirely. Anything else is a feel good band-aid.

With the advent of Start/Stop being proven to be what it is; idiotic nonsense, I'm sure there will be a software reload coming down the pike.

Until then, I have two batteries and I hit the button after every start-up and whine about it. I knew it had it when I bought it.

It is what it is.

I think I need a cuppa coffee....

 

[Pismo61]

Okay, maybe I'm showing my age, but I'm of the mindset of that "it came with it, so suck it up buttercup". Do I like having two batteries ? Not at all, I think the whole Start/Stop thing is stupid as hell. But the vehicle is designed around it; hardware AND software, it is what it is.

As I was recently replacing both batteries (I went through the top and it really wasn't that bad), I kept repeating "stupid crap to do to replace freaking batteries". But I sucked it up. If it was something I had to do monthly, yeah, I'd try to find a "cure". But once every 3-4 YEARS ? I'll leave it factory, thank you very much. Disconnecting cables, pulling fuses, etc. is the ultimate in "Band-Aid repairs"; you didn't "fix" squat, you're fooling not only the Jeep, but yourself. Start/Stop is still there, trying to run the program loaded.

The ONLY true fix would be a complete software re-write, not a plug in gizmo, not a disable hack via OBD, not taping off terminals, but a complete Operating System re-write to remove the Start/Stop programming entirely. Anything else is a feel good band-aid.

With the advent of Start/Stop being proven to be what it is; idiotic nonsense, I'm sure there will be a software reload coming down the pike.

Until then, I have two batteries and I hit the button after every start-up and whine about it. I knew it had it when I bought it.

It is what it is.

I think I need a cuppa coffee....

My thoughts also and I use a battery tender.Its garaged and use the quick connector so no big deal.

 

[Mr Miami]

Okay, maybe I'm showing my age, but I'm of the mindset of that "it came with it, so suck it up buttercup". Do I like having two batteries ? Not at all, I think the whole Start/Stop thing is stupid as hell. But the vehicle is designed around it; hardware AND software, it is what it is.

As I was recently replacing both batteries (I went through the top and it really wasn't that bad), I kept repeating "stupid crap to do to replace freaking batteries". But I sucked it up. If it was something I had to do monthly, yeah, I'd try to find a "cure". But once every 3-4 YEARS ? I'll leave it factory, thank you very much. Disconnecting cables, pulling fuses, etc. is the ultimate in "Band-Aid repairs"; you didn't "fix" squat, you're fooling not only the Jeep, but yourself. Start/Stop is still there, trying to run the program loaded.

The ONLY true fix would be a complete software re-write, not a plug in gizmo, not a disable hack via OBD, not taping off terminals, but a complete Operating System re-write to remove the Start/Stop programming entirely. Anything else is a feel good band-aid.

With the advent of Start/Stop being proven to be what it is; idiotic nonsense, I'm sure there will be a software reload coming down the pike.

Until then, I have two batteries and I hit the button after every start-up and whine about it. I knew it had it when I bought it.

It is what it is.

I think I need a cuppa coffee....

I agree. We knew what we were buying. We knew (or I think the people here knew) that there were two batteries. We knew there was a stop/start thing. Even my wife's previous BMW ('16 320i) had it and her newer one ('21 X3) has it. To the best of my knowledge, new cars have it.

Do I like it? Mixed feelings. If it defaulted to "off", I would like it a little bit. Maybe there are cases in some stop/start driving in traffic that it would save a few cents here and there. "Worst" case scenario, I press the button and it goes away. Not that big of a deal.

When I get in the vehicle, I pull my seatbelt over my chest and click it until it locks. Would I prefer to do it automatically and not have to "waste" that second or two to lock the seatbelt? Probably not. Some here may remember back in the 70's (if I remember correctly) that there was an automatic seatbelt thing that came across your chest when you got in the car and you really didn't have to do anything. I guess people didn't like it, they preferred the manual pull and click process.

So clicking the seatbelt is no big issue with me. Nor is pressing a button when I get in to deactivate the stop/start. I generally adjust the radio when I get into the Jeep. That takes time too.

Two batteries? It is what it is. I used to change my own spark plugs. Not anymore. With all the stuff squeezed into the engine compartments nowadays, it's hard to even find them, especially for those of us not particularly mechanically inclined.

It is what it is. I knew it when I bought it. There were no surprises, nothing I really didn't know.

It is what it is.

 

[Labrat1970]

help
im getting my 4rth aux batt replaced w only 19k on the 23 jeep

after getting "car will shut down errors" i pulled over and tried to charge the Li batt w a back up and also tried to do the delete since the main was at 12.8 v.
the delete didnt work and left the car dead, i tried each neg lead and nothing.
The car would only start w both neg leads connected but would die in 20 seconds showing 8V on the dash battery gauge. So the cars reading the aux under load and ignoring the main.

the weirdest part was when meter testing the aux lead w the pos on the main battery it read 22.8V which is series for the main and the 10v from the aux. How is this possible?

last i noticed they have the small wire grounding the jeep and the fat wire going to the aux

something is definitely not wired right somewhere there!!

 

[Labrat1970]

Okay, maybe I'm showing my age, but I'm of the mindset of that "it came with it, so suck it up buttercup". Do I like having two batteries ? Not at all, I think the whole Start/Stop thing is stupid as hell. But the vehicle is designed around it; hardware AND software, it is what it is.

As I was recently replacing both batteries (I went through the top and it really wasn't that bad), I kept repeating "stupid crap to do to replace freaking batteries". But I sucked it up. If it was something I had to do monthly, yeah, I'd try to find a "cure". But once every 3-4 YEARS ? I'll leave it factory, thank you very much. Disconnecting cables, pulling fuses, etc. is the ultimate in "Band-Aid repairs"; you didn't "fix" squat, you're fooling not only the Jeep, but yourself. Start/Stop is still there, trying to run the program loaded.

The ONLY true fix would be a complete software re-write, not a plug in gizmo, not a disable hack via OBD, not taping off terminals, but a complete Operating System re-write to remove the Start/Stop programming entirely. Anything else is a feel good band-aid.

With the advent of Start/Stop being proven to be what it is; idiotic nonsense, I'm sure there will be a software reload coming down the pike.

Until then, I have two batteries and I hit the button after every start-up and whine about it. I knew it had it when I bought it.

It is what it is.

I think I need a cuppa coffee....

The only thing I don’t like is not being able to “see” the voltage of the aux battery to monitor it like one can monitor the main. That should have been a thing we can see.

 

[Mud Pie]

The only thing I don’t like is not being able to “see” the voltage of the aux battery to monitor it like one can monitor the main. That should have been a thing we can see.

Agree 100 %. Sure, you can meter the leads from the battery (after disconnecting them from the terminal blocks) but that is WAY too much effort. Should be a scroll button on the dash.

 

[ShadowsPapa]

Agree 100 %. Sure, you can meter the leads from the battery (after disconnecting them from the terminal blocks) but that is WAY too much effort. Should be a scroll button on the dash.

LOL
And just how would you do that since they are connected to each other in parallel at almost all times.
Be observant, there are often clues.........

 

[ShadowsPapa]

the weirdest part was when meter testing the aux lead w the pos on the main battery it read 22.8V which is series for the main and the 10v from the aux. How is this possible?

IMPOSSSIBLE.
These are never in series, ever, unless you did something drastically incorrect.

There's so many mistaken notions and so much bad, even horrible info in some of these threads - it's no wonder I avoid this place more often than not

This reply is a bit off of the post but....I deleted the Mopar Aux battery and pulled the fuse 42. But I still get the Stop/Start failure warning and the '(A)! light. Is the 'fix' immediate or does it take some time?

LOL - stop/start will always be there, you did NOTHING but take the aux battery out of the mix. You fixed nothing, you deleted nothing, you disabled nothing.
You have some other issues that need to be addressed.

Like I said above - there's more bad info in threads like this than good solid factual information.
You can't possibly take stop/start away. It's aways there, period. Tazer or not, aux battery or not.
You have some other issues going on and it's telling you that there are issues going on.
They won't just go away.
It's very possible you have a main battery going bad, a bad connection or perhaps one of the over 3 dozen things the stop/start monitors is problematic. Check for codes.
But taking out the aux battery fixes nothing other than if you happen to have a bad aux battery. It doesn't fix or resolve any other problems and does NOT, I repeat NOT, disable the stop/start, ever, period.

 

[Mud Pie]

One of the best "tip and tricks" I saw on YouTube was; to reset the computer on a JL or JT, disconnect both terminals from the Main battery posts and short the positive and negative battery cables together for 5-10 seconds. I did the WHAT ?!?!! then read the comments. Yeah, people blew their stuff up. Yet the post remains and has a crazy high view count.

My opinion ? A Toyota owner getting his giggles.

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