3.6L ESS Aux Battery Bypass

Rubi

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I completely removed the auxiliary battery and wiring about 2 weeks ago due to a bad aux battery but learned something important if you do it this way. A 30 amp fuse is not enough to carry the max load of everything powered by the N1 terminal and when that fuse blows under those conditions it definitely lets you down and you don't have emergency flashers, windows won't roll up and down, etc. I did an amperage check and I was seeing 30.9 amps with heater blower at full blast and radio at about half volume, so I came off of N3 which originally fed the aux battery and is fused at 150A and ran a 6 gauge jumper to N1, I feel more comfortable doing it that way instead of a jumper from N2 to N1 which would have no fusing and could carry whatever current the main battery could provide.
Excellent procedure; the most simplest route is always the best. If I disconnect the hood open switch, to disable ESS, will there be any related problems other than the dash warning light?





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WranglerMan

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Excellent procedure; the most simplest route is always the best. If I disconnect the hood open switch, to disable ESS, will there be any related problems other than the dash warning light?
no there will not be any issues, I believe you could also disconnect the IBS coming off the main negative ..
 

WranglerMan

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I do not advocate for removing the aux battery and when I rewire mine it will be to eliminate the issues related to the unmanaged interaction of the batteries by having some kind of manual management.
Could you not just remove the ESS negative then jumper between N1 and N2 with a jumper wire large enough and fused properly, I have even thought about putting a disconnect in between the ESS negative off the main so you could just flip a switch to disconnect it

As I have said over and over I don’t mind there be a baby battery in the system but they surly could have made it easier to get to
 

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i simply installed a brand new optima red top battery... my ESS stopped working and i get no errors at all, seams like that style of battery the way it stores energy and charges effects the second battery from fully charging but allows enough to keep it from throwing an error
 
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Jebiruph

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Could you not just remove the ESS negative then jumper between N1 and N2 with a jumper wire large enough and fused properly, I have even thought about putting a disconnect in between the ESS negative off the main so you could just flip a switch to disconnect it

As I have said over and over I don’t mind there be a baby battery in the system but they surly could have made it easier to get to
This is basically what i'm looking to do. Run without the aux battery, but monitor it's voltage and control whether it's connected or not with a switch.
 

c2m2h3

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Jerry,

If you are running without the AUX Battery, do you mean removing it or just disconnecting it ?

And, if it is still installed and you can "connect" it by a switch, my question is why would you need to do that ? Are you using it for ESS or do you not have that feature enabled (by way of a flash cal, etc) ?

Lastly, if you can completely disable it, and you don't use ESS, why not remove it completely ? or is there some other feature that the AUX Battery is responsible for ?

Sorry again for my lack of electrical knowledge......

Thanks as always !
 
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Jebiruph

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Jerry,

If you are running without the AUX Battery, do you mean removing it or just disconnecting it ?

And, if it is still installed and you can "connect" it by a switch, my question is why would you need to do that ? Are you using it for ESS or do you not have that feature enabled (by way of a flash cal, etc) ?

Lastly, if you can completely disable it, and you don't use ESS, why not remove it completely ? or is there some other feature that the AUX Battery is responsible for ?

Sorry again for my lack of electrical knowledge......

Thanks as always !
I would connected it for charging and otherwise disconnect it.

I manually disable ESS, so don't need it for that.

At the very least it would be an emergency backup. If and when the main battery can't power a start, the aux battery could be switched in to provide additional power.
 

c2m2h3

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You are a wise man....


Thanks, Jerry
 

jeepdabest

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I would connected it for charging and otherwise disconnect it.

I manually disable ESS, so don't need it for that.

At the very least it would be an emergency backup. If and when the main battery can't power a start, the aux battery could be switched in to provide additional power.
What happens if you simply remove the neg aux battery cable? Do you still need jumper?
 
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Jebiruph

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What happens if you simply remove the neg aux battery cable? Do you still need jumper?
Yes, or you have to unplug the PCR due to the cold start testing of the aux battery.
 

c2m2h3

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If someone were to merely disable the ESS System upon each star (push the button), are there any other modifications that "need" to occur ?

If I am understanding it correctly, it appears that the battery system design makes it almost impossible to jump start (say with a jump pack, if you are on a trail or remote somewhere); however, with the Jumper Wire that Jerry came up with that is no longer an issue.

Are there any additional issues with the system as is ? It seems that the AUX Battery may be either faulty and/or slowly drained from the way it was designed.....

Is that a fair understanding ?
 
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Jebiruph

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If someone were to merely disable the ESS System upon each star (push the button), are there any other modifications that "need" to occur ?

If I am understanding it correctly, it appears that the battery system design makes it almost impossible to jump start (say with a jump pack, if you are on a trail or remote somewhere); however, with the Jumper Wire that Jerry came up with that is no longer an issue.

Are there any additional issues with the system as is ? It seems that the AUX Battery may be either faulty and/or slowly drained from the way it was designed.....

Is that a fair understanding ?
Disabling the ESS system does not eliminate the aux battery cold start test or prevent the adverse effects of having the two dissimilar batteries connected.

It is not impossible to jump start, it's just that it can take more power to jump start with two dead batteries. If the aux battery has completely failed and can't hold any charge, the fused jumper or unplugging the PCR gets past the cold start aux battery test.

It's a complicated system that does not summarize well. For the most part, treat it like any other car, but have a plan (fused jumper or PCR unplug) to over come a failed aux battery.
 

WranglerMan

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@Jebiruph i have one of the early jumpers you were working with and I believe it has a 30 amp fuse in it, I know this is likely undersized but would it work in an emergency situation

Here is basically what I have

E4FFD88B-B493-467B-968B-DD6A8981DF0E.jpeg
 

c2m2h3

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At this point my plan would be to either permanently disable the ESS feature (using a flash cal or something similar) or just press the button upon starting (which I would think would get rather routine).....I plan to fabricate a Jumper that you designed (with probably a 40 amp fuse) and use that with a strong jump pack, should I ever need to jump it. I too plan to upgrade to an Odyssey Extreme Main Battery as well.

Am I missing something ? Are the AUX Batteries bad or slowly draining ? is the alternator not charging both while in use ?
 

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A while back one of the you tubers I watch, Kevin and Britney with Lite Brite, showed a way to jump the jeep using a jumper wire. Was this related to possibly a bad aux and then using the bypass that has been stated in this thread? Or did he do something else to “jump” the jeep? Just trying to make sure I understand. I plan to build a jumper wire as well per the instructions in this thread as I don’t want to be stranded while camping or off roading.

I did a search and can’t for the life of me find the episode where Kevin does this, maybe someone on here has a link to it but either way. Would like to know what he did so I don’t end up stranded.
 
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