3.6L ESS Aux Battery Bypass

[Jebiruph]

I thought the original intent of this post was to show a way to bypass the AUX battery if you get stranded. Am I missing something??

Who knew bypassing the Aux battery, temporarily or permanently and for whatever reason, would be so popular. Do you have a question or are you just making a comment?

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[drdriller]

Both. First statement is a comment. Second statement is a question.

 

[Jebiruph]

Both. First statement is a comment. Second statement is a question.

Then, no.

 

[WranglerMan]

I for one have thoroughly enjoyed keeping up with this and am glad that someone like @Jebiruph has the skill to understand how this system is designed and break it down in simple terms and diagrams that I can understand, I currently have a wingnut on my ESS negative and have the jumper in the glove box and if needed will toss the jumper on and pull the ESS negative so I can get on the road, I have actually thought about leaving the Jumper on all the time and have the ESS negative off and then once a month just use my meter to check the ESS battery voltage and reconnect the negative as needed to maintain a good charge on it but I’m not sure that would be good to maintain good battery health as a battery that never gets used tends to have a short life but who knows

 

[Oakwolf]

It's really interesting that you guys have knowledge and share it so we might attempt to understand. I mean it could actually save someone alot of fuss if they become stranted. I my case, it could actually mean saving the jeep from a salt water tide as i am under a timer to reach my destination. If this works in a permanent set up, and you can effectively remove the aux batt...it makes me wonder why it is there in the first place anyway?

 

[WranglerMan]

It's really interesting that you guys have knowledge and share it so we might attempt to understand. I mean it could actually save someone alot of fuss if they become stranted. I my case, it could actually mean saving the jeep from a salt water tide as i am under a timer to reach my destination. If this works in a permanent set up, and you can effectively remove the aux batt...it makes me wonder why it is there in the first place anyway?

I’m quite sure the ESS battery was added as the Jeep had ESS before from my understanding and utilized the same battery so maybe this is the improved version but to me the location of the ESS battery is the rub as it’s in a terrible location

 

[William Hays]

FYI
Bypassed the AUX Battery with a "Tinned Copper" Bar @ Terminals N1 & N2 from my parts stash. The Copper Bar is a cutoff from a 2 Hole Grounding Lug. Also disconnected the AUX Ground Cable. Electrically, short circuit protection Up Stream to the Batteries & Down Stream to the PDC is the same with or without the Bypass.

 

[WranglerMan]

What benefit does disconnecting the aux ground do, I would think if you jumped N1 to N2 and disconnect the ESS negative off the main it would be the same or am I missing something

 

[William Hays]

I think we are talking about the same thing.

 

[Rubi]

FYI
Bypassed the AUX Battery with a "Tinned Copper" Bar @ Terminals N1 & N2 from my parts stash. The Copper Bar is a cutoff from a 2 Hole Grounding Lug. Also disconnected the AUX Ground Cable. Electrically, short circuit protection Up Stream to the Batteries & Down Stream to the PDC is the same with or without the Bypass.

Excellent solution with the tinned copper bar connector. Why don’t you disconnect the lead from N3 as well. With the aux ground and N3 disconnected the battery is 100% out of the circuit. I would also disconnect the under hood switch to guarantee ESS doesn’t come into play at all.

 

[WranglerMan]

I think we are talking about the same thing.

Your just disconnecting it from the other end correct ?

 

[William Hays]

Excellent solution with the tinned copper bar connector. Why don’t you disconnect the lead from N3 as well. With the aux ground and N3 disconnected the battery is 100% out of the circuit. I would also disconnect the under hood switch to guarantee ESS doesn’t come into play at all.

I could completely remove all connections to the AUX Battery, and there would be nothing wrong with that. However to completely disconnect the AUX Battery, I would need to remove both N3 & N1 and ensure they were taped up securely. Just not tidy enough for this retired electrical engineer. With the AUX Battery negative cable removed, it is electrically out of the circuit and easily restored to OEM operation if dealer might complain.

As soon as I get my "Off Road" pages code TSB installed by dealer on Tuesday, I will be using my Tazer to eliminate the Auto ESS.

It is my understanding that TSB 08-001-19 to restore OFF Road Pages for the 8.4 UConnect was released earlier this week.

 

[William Hays]

If anyone gets any pushback from an uninformed service department concerning your AUX Battery Bypass, here is a reply that should be good to go.

"Have had intermittent trouble with both batteries being run down over night. Everything is working just fine ever since eliminating the AUX Battery. It was a total embarrassment to ME, my Wife, all my Toyota 4x4 peers, and FCA every time I had to jump start my JL. DON'T MESS WITH IT"

 

[Jebiruph]

FYI
Bypassed the AUX Battery with a "Tinned Copper" Bar @ Terminals N1 & N2 from my parts stash. The Copper Bar is a cutoff from a 2 Hole Grounding Lug. Also disconnected the AUX Ground Cable. Electrically, short circuit protection Up Stream to the Batteries & Down Stream to the PDC is the same with or without the Bypass.

Are you concerned at all that in the unlikely situation where the AUX ground gets reconnected and the main positive terminal is disconnected and accidentally grounded (this does happen), you will have an unfused short circuit from AUX positive to ground?

Jeepinformant discusses it in this video (but I don't think he is identifying the terminals correctly)

 

[William Hays]

Are you concerned at all that in the unlikely situation where the AUX ground gets reconnected and the main positive terminal is disconnected and accidentally grounded (this does happen), you will have an unfused short circuit from AUX positive to ground?

Jeepinformant discusses it in this video (but I don't think he is identifying the terminals correctly)

What you describe would be a bad day. My post may have been misleading. The only cable I disconnect is the AUX Battery negative. In my career I worked with Standby Battery Systems that weighed over 3 tons. I am definitely concerned about battery fires. Have witnessed first hand what can happen with a fallen tool across the full battery stack output. Seen the handle of a 3/8 ratchet glow red and then disappear in about 1.5 seconds. Looking for a rubber end cap of proper size to slide over the end of the AUX negative lead for a added layer of protection while disconnected.

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