3.6L ESS Aux Battery Bypass

Gee-pah

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After reading through this entire topic; this is my summation of how to modify a 2018 3.6l to run without an aux battery and not have to have it reflashed at the dealer as detailed above. Anybody, please correct me or add any additional steps not called out below

Disconnect the power control relay connection from T3 fuse block terminal, wrap it with electrical tape or completely remove the relay from the vehicle.

Disconnect the positive lead connection at the aux battery, reconnect this lead to the main battery.

Disconnect the negative aux battery connection, wrap it with electrical tape

Additional question; can the the aux battery main positive cable be easily connected to the main battery? Please explain exactly what has to be done to accomplish this reconnection.

I also disabled ESS through the hood open switch. I will also be removing the aux battery from the vehicle.

Thank you.
Hey Rubi:

Let's look at Jerry's diagram:

https://www.jlwranglerforums.com/forum/threads/ess-dual-battery-management.60034/

Requests for power from the ESS/Aux battery initiate at point N1. If you, with low gauge wire (i.e. thick) and high amp fuse connect N1 to N2, you will redirect power requests from the ESS/Aux battery to BOTH the main battery and the ESS/Aux battery. This is because N1 will now "shout out" to the ESS/Aux battery and N2: which is connected to the main battery.

This brings up to step two:

Disconnect the negative cable from the ESS/Aux battery to the main battery. Now all requests for power from the ESS/Aux battery, which again, originate out of N1, get rerouted to N2, the main battery. Jerry's diagram features a beyond factory on/off switch because he was demonstrating features he was introducing in this post , but the concept remains the same. Two big wires come off the negative post of the main battery. One, which you'll leave along, runs to the body ground. The other, which you'll yank, comes from the ESS/Aux battery.

Once disconnected, cover this cable end coming from the negative terminal of the ESS/Aux battery with electric tape (as I think you mentioned) for me, okay?

So we're clear, your question "can the the aux battery main positive cable be easily connected to the main battery? Please explain exactly what has to be done to accomplish this reconnection."

is yes, hardwire N1 to N2.
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WranglerMan

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@jeepoch unlike you I despise ESS as here in South Texas I don’t need my engine off in the heat and unless my A/C is in an active cycle it shuts down so after jumping away from the Tazer i went to a Smart Stop/Start module so ESS is and always will be off.

Now in regard to your question on making the Genesis system work with ESS I’m thinking with the way the JL looks at the voltages as @Gee-pah pointed out you will be limited to 6 cycles then ESS will be disabled until the ignition is cycled and I don’t think there is a way around this and this is why.

With the Genesis system there is a Cole Herssee smart relay that is coupled with a solenoid and it dictates when the batteries are separated but here is how it works, upon initially starting the smart relay looks at the voltage of the main crank battery and once it see’s 13.2 volts or higher for 2-3 mins it tells the solenoid to energize and connects the two batteries and they are seen as one, the initial reason for this on starting is to reduce the load on the alternator for starting but once they are connected the voltages between the two batteries equalize and the logic in the JL see’s this and assumes as @Gee-pah pointed out it’s seen as a fault and after 6 cycles it disables ESS, not sure why the 6 cycle limit but guessing the JL gives things a chance to work out. I have tested this many times for just testing and it never fails after 6 cycles if fails and on a recycle it resets.

Some that have looked at the Genesis system and don’t like the fact that the IBS is connected to the second battery because if the batteries are separated and the second battery if almost fully charged then it does not direct the alternator to charge the main crank battery but to be honest the batteries are connected as one 99% of the time and say you park your Jeep for several days power that is pulled thru the PDC all pull from the main crank battery and once it gets down to 12.7 +/-.1 it disconnects from the second battery and if you were to say have something like a dash cam run the crank battery down and it won’t start a simple push of the boost button gets you going and I have tested this and it works perfectly.

So in closing yes I am a huge Genesis fan ( Pretty obvious ) but I like what is offers, is it a perfect system …..NO ITS NOT as I would prefer the solenoid not pull as much power as it does but that’s a small price to pay for the end benefit to me.

You may want to contact Shane or Mike from Genesis but I’m doubting there is a work around for the ESS cycle limit
 

Rubi

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Hey Rubi:

Let's look at Jerry's diagram:

https://www.jlwranglerforums.com/forum/threads/ess-dual-battery-management.60034/

Requests for power from the ESS/Aux battery initiate at point N1. If you, with low gauge wire (i.e. thick) and high amp fuse connect N1 to N2, you will redirect power requests from the ESS/Aux battery to BOTH the main battery and the ESS/Aux battery. This is because N1 will now "shout out" to the ESS/Aux battery and N2: which is connected to the main battery.

This brings up to step two:

Disconnect the negative cable from the ESS/Aux battery to the main battery. Now all requests for power from the ESS/Aux battery, which again, originate out of N1, get rerouted to N2, the main battery. Jerry's diagram features a beyond factory on/off switch because he was demonstrating features he was introducing in this post , but the concept remains the same. Two big wires come off the negative post of the main battery. One, which you'll leave along, runs to the body ground. The other, which you'll yank, comes from the ESS/Aux battery.

Once disconnected, cover this cable end coming from the negative terminal of the ESS/Aux battery with electric tape (as I think you mentioned) for me, okay?

So we're clear, your question "can the the aux battery main positive cable be easily connected to the main battery? Please explain exactly what has to be done to accomplish this reconnection."

is yes, hardwire N1 to N2.
Gee-pah, Thanks for taking the time to respond in a very detailed manner. I'm very much aware of your explained technique of linking N1 to N2 with a fusable link connection.

I was referring to the post #198 from this thread shown below. MoparTH said he removed the aux battery and all associated wiring and connected a 6 AWG non-fused connection from N1 to N3. I agree with MoparTH and feel more comfortable in connecting N1 to N3. Jebiruph responded and said "This leaves redundant wiring ..." then includes a stripped wiring diagram showing both N1 & N2 connected to the main battery with N3 disconnected from the PCR. This explains my step in reconnecting the disconnected aux battery positive cable to the main battery. As you know the aux battery in stock form connects to N1.

From my original explanation/question, does disconnecting N3, completely isolating the PCR from the circuit shown below, cause the system to put the vehicle into a shutdown mode where it has to be towed to a dealer and be reflashed? Again thanks for taking the time to read through my question.

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Rock Hopper

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Gee-pah, Thanks for taking the time to respond in a very detailed manner. I'm very much aware of your explained technique of linking N1 to N2 with a fusable link connection.

I was referring to the post #198 from this thread shown below. MoparTH said he removed the aux battery and all associated wiring and connected a 6 AWG non-fused connection from N1 to N3. I agree with MoparTH and feel more comfortable in connecting N1 to N3. Jebiruph responded and said "This leaves redundant wiring ..." then includes a stripped wiring diagram showing both N1 & N2 connected to the main battery with N3 disconnected from the PCR. This explains my step in reconnecting the disconnected aux battery positive cable to the main battery. As you know the aux battery in stock form connects to N1.

From my original explanation/question, does disconnecting N3, completely isolating the PCR from the circuit shown below, cause the system to put the vehicle into a shutdown mode where it has to be towed to a dealer and be reflashed? Again thanks for taking the time to read through my question.

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I think this is why so many of us remain confused!!!

Shouldn't there be a simple way (that we all agree on) that would delete the small battery (provided the ESS is disabled) and have our Jeeps operate like a normal 1 Battery vehicle?

Seems that shouldn't be too much to ask, right? Sadly It looks like it is-at least for now.
 

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@Rubi, @Rock Hopper, I've reread your original posts and the ones immediately above. I'll do my best here to convey what I know in really straight forward terms.

First off, let's talk about what motivates many owners: and that is the removal of the ESS/Aux battery from the 3.6L JLs, or at least the removal of any dependencies of this small battery on getting our rigs to operate correctly. The battery is unreliable, and as designed in the 2018, represented a true weakness, an Achilles Heel if you will, it getting the original 3.6JL to crank. This is because if that little battery lacked sufficient power the rig would not crank, even if the main battery leads were attached to a nuclear power plant, let alone a fully charged main battery.

Still more, even though this issue was resolved in model year 2019 and later 3.6L JL's, and with a TSB as discussed above for 2018s, many of us don't mind disabling ESS functionality--better put enjoy its outright disconnection, and would like to simplify our 3.6L's to run with one battery given that no ESS battery should be needed if there's no ESS system engaging.

Of course you can disengage ESS but given the design of the the electrical system of the 3.6L by Stellantis, taking the ESS battery out of the circuit, and/or removing it from the vehicle should involve rerouting the wiring that normally connected to this ESS battery, to other places.


Before discussing the evolution of resolving this problem it may help if we get some definitions in place regarding some of the slots on the high amp fuse bar located on the driver's side of the Power Distribution Center (PDC).

N1 is a hard wired connection to the positive terminal of the ESS/Aux Battery.

N2 is a hard wired connection to the positive terminal of the main battery.

N3 is a relay controlled connection to the positive terminal of the ESS/Aux battery--which begs the question: what's a relay?

A relay is an electronic switch.

"Oh, like the one on the wall that controls the lights in my kitchen?"

No. That's a manual switch. You exerted calories to flip that light switch manually with your finger.

A relay turns on and off a connection with electrical power. The power to close that connection could arguably come from someplace entirely different than the power that flows through that relay's circuit when it is closed..or not.

Classic example: the sparker in my home furnace is energized by a relay that uses 120 VAC to make the spark, but, that 120 VAC circuit will not be closed (and no spark will occur) until a 12V DC circuit that makes the home thermostat run tells it to do so. Why the complexity? Because it's safer to work with 12V DC on the thermostat---you don't even need an electrician to do the wires...but 12V DC would not be enough to run the sparker.

Then, when it comes to relays, there is the concept of "normally open," and "normally closed" ones. A relay which allows the power to flow through the relay when the relay itself is not energized is thought of as normally closed. The relay connected to N3 is normally closed. And in terms of real world application here, it just means that the main and ESS/Aux batteries are normally connected to each other in parallel, and it takes energizing that relay on N3 to break the connection between the two batteries.

No surprise, when the 3.6L is at rest, those two batteries are connected in parallel--in fact out of the factory they always are but for an instant at cold crank where they are separated, (so the voltage of the ESS/Aux battery can be evaluated all on its own by the rig,) and during ESS events. Otherwise, 99.9% of of the time those two batteries are connected in parallel.

Maybe at this point you are seeing N1 and N3 as, well, redundant. After all they both connect to the positive terminal of the ESS/Aux battery.

Maybe this is the redundancy @Rubi that you refer to Jerry @Jebiruph referring to. But appreciate that in situations where the relay connected to N3 is energized, the switch inside that relay has its connection temporarily severed between N3 and the ESS battery, and the two batteries are isolated by this. So any connection between N3 and N2 (think of N2 as the main battery positive) is not energized if that relay is open (i.e. the relay is energized, as is the case for an instant at cold crank and during ESS events.)

On the other hand N1 is not subject to the status of the relay on N3. It is a direct connection to the positive terminal on the ESS/Aux battery, and connecting N1 to N2 (think of N2 as the main battery positive) is making both batteries connected in parallel 100% of the time no matter what state the relay on N3 is in.

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

With these explanations behind us, and I appreciate that many know this, we are now in a better place to talk about the implications of various wiring schemes people have put into the 3.6L JL since its rollout.

The grandfather of all this discovery is Jerry @Jebiruph. We are indebted to him not merely for the workarounds he's devised, but the understanding of why they work the way they do.

Jerry's version 1.0 workaround, which he devised not long after the 3.6L JLs introduction, was placing a fused jumper between terminals N1 and N2. Ok, Jerry initially went with gauge wiring and a fuse that for some, as you reported above @Rubi, may have not been adequate. To me that spells using thicker (lower gauge) wire and a higher amp fuse compatible with that thicker wiring--not a stab at Jerry's approach.

And when he did this he insured that a 2018 3.6L could still crank even if the ESS/Aux battery was dead, because all calls to either of the batteries for power went to both batteries by virtue of this N1->N2 connection.

Jerry later introduced more complex wiring schemes that put the owner in far greater control of power management. His more advanced wiring designs not only permitted determining the voltages of each battery separately, but by turning on and off a bunch of switches he could have the 3.6L behave as per factory, or run with both batteries hard wired, or eliminate either (but of course not both) of the batteries from the rig's circuitry at will.


In Jerry's initial design of connecting N1 and N2 I imagine that after 6 cold cranks, where the rig saw the voltages of each of the batteries as the same (because the batteries were hard wired and produced one composite voltage by virtue of this N1 -> N2 jumper) ESS was automatically and eventually disengaged, but because ESS events no longer isolated the two batteries (because the energized relay at N3 no longer separated the batteries because the hardwired N1->N2 connection was in place, rendering the state of the relay on N3 as moot) it wasn't wise to tax the main cranking battery during an ESS event.

~~~~~

With all of this academic stuff behind us, what separates the two batteries is N3 not being connected to anything else (i.e. N1, N2, etc) and its relay being energized. But--and this is an important but, if you connect N1 and N3, what you are effectively doing, I think, for better or worse, is always keeping the ESS/Aux battery connected, irrespective of the state of the relay at N3. What I don't think you're doing though is hard wiring the two batteries together as N2, which is the main battery's positive terminal, is not connected to N1 or N3, etc.

Suppose that relay on N3 is energized and the connection between N3 and ESS/Aux battery is disconnected, with that jumper between N3 and N1, another route to the ESS/Aux battery's positive terminal can be taken through N1, bypassing the relay and its status on N3 all together-but again, I'm not sure that the two batteries are connected.

I say this because I have to think that Jerry connected N1 to N2 for a reason, and that connecting N1 to N3 may get around the state of the relay on N3 getting in the way of accessing the ESS/Aux battery, but it may still not connect the two batteries.

@Rubi, in Jerry's stripped wiring diagram I do not see N1 & N2 connected to the main battery (positive) as you report. Bear in mind that N2 and the main battery positive are one and the same (there is a an unaltered factory wire between the two) but I don't see N1 connected to N2, and thus the main battery.

"This explains my step in reconnecting the disconnected aux battery positive cable to the main battery. As you know the aux battery in stock form connects to N1. "

Well Rubi, if you do not connected N1 to N2 at the PDC, and you want the two batteries hard wired in parallel, your step of reconnecting the disconnected aux battery positive cable to the main battery will be required, and the cable that leads from the ESS battery negative to the main battery negative will need to remain intact.

Had you connected N1 to N2 this step you took of reconnecting the disconnected aux battery positive cable to the main battery would have been redundant. Maybe this was the redundancy Jerry was referring to.

~~~~~~~~~~

@Rubi, you refer to concerns about putting your rig in jeopardy of shutdown. I think the best way of my addressing this with you is as follows.

A 3.6L JL can run just fine with the main battery disconnected--provided the ESS/Aux has power.

This fact, stated more technically can be restated as saying that if N1 sees power (remember he's hooked up to the ESS/Aux positive) you are good.

N1 seeing power can come in many forms. One is an energized ESS/Aux battery. Another is it being fused to N2 (the main battery positive) and the main battery having power.

@Rock Hopper Dave: I hear your cry for simplicity. The most direct way to delete the ESS battery (with as you point out ESS disabled) is to jumper N1 to N2 using gauge wire that can handle a fuse exceeding the 30 amps Jerry originally used (as per @MoparTH)

and disconnecting the cable from the main battery's negative post that goes back to the ESS/Aux battery's negative post. That's it.

There are two cables on the main battery's negative post. Leave the one that goes to the body ground on the front passenger's quarter panel intact. Disconnect the other cable...that's the one that leads to the ESS/Aux battery's negative terminal.

Doing this all calls to the ESS/Aux battery get rerouted to the main battery. No complete circuit now exists to and from the ESS/Aux battery because you have yanked its negative.
 
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Jebiruph

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Will,

I too am really thinking about investing in the Genesis Dual Battery system, if for nothing other than just replacing the AUX with a similar sized MAIN. The Genesis solution looks to be so much superior than anything FCA has provided.

It looks like FCA (Stellantis) has eventually solved the ESS disaster with the non-optional eTorque system with a 48v battery solution, but I digress.

Regardless, what I'd like to do is simply puzzle out how to rid my 2019 Sport of the AUX without losing the ESS functionality altogether. I absolutely despise that this ESS functionality was shoved down our throats due to CAFE and Carbon Tax bureaucracy, (but that's an entirely separate topic).

However, and I admit I'm the oddball here, I really don't mind not wasting fuel when idling. In fact, it has become rather fun playing with the dynamics of letting it engage (or not) given all the various stopping conditions I regularly find myself in.

Some people like playing with the clutch, well it turns out I like playing with either the ESS pushbutton or the hardness / lightness of the brake pedal nearly every stop. So while most people see this as a pure unadulterated nuisance, I'm having a lot of fun with it. Really.

I'm loving everything about my JL experience both on and off-road but I unceremoniously despise this AUX battery design. It Sucks with a capitol 'S' for ALL the reasons stated in this thread. I'm hoping to pull the trigger soon, before needing to replace this god-awful AUX battery contraption. Also hoping not to get stranded in the meantime.

However I have to do my homework and puzzle out how to rewire the Genesis system to play nicely with the IBS and PCR so that the ESS isn't automatically disabled every six cycles. Jerry's (@Jebiruph), your's and others most excellent posts regarding this subject lead me to believe that the IBS must be able to sense two (2) independent battery voltages, rather than an identical single instantaneous voltage measured twice from one battery in order to keep ESS enabled for more than the six cycle limit. The engine controller can't be easily fooled into a false sense of happiness simply by jumpering the two together as in the overall solution everybody here is clambering to install.

So I know it's possible to simply replace the AUX battery with the Genesis second one but without having the Genesis system to puzzle this out, I'd like to know what specifically needs to be done before pulling the trigger. Since you already have this system, even though you've disabled ESS outright, do you have any thoughts or idea's on this oddball configuration.

I suppose I can contact Genesis (perhaps even Mr. Shane) to work this all out. Maybe I could then also select which is the Main and which is the AUX as the batteries inevitably will wear differently over time.

Either way I would really appreciate your thoughts.

Thanks a bunch for all your previous posts.
Jay
If all you want to do is replace the aux battery with a bigger battery and maintain the factory ESS system, you can get just the Genesis dual battery tray and wire the batteries up exactly as the factory batteries are wired. What you might like better is @SpookyXJ 's circuit that keeps ESS, but separates the batteries when the ignition is off which prevents one battery from draining the other. https://www.jlwranglerforums.com/forum/threads/genesis-diy-dual-battery-tray-wire-layout.43974/
 
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I think this is why so many of us remain confused!!!

Shouldn't there be a simple way (that we all agree on) that would delete the small battery (provided the ESS is disabled) and have our Jeeps operate like a normal 1 Battery vehicle?

Seems that shouldn't be too much to ask, right? Sadly It looks like it is-at least for now.
Wire it like this.
stripped wiring.PNG
 
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Jebiruph

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I've been running with no aux battery for about 1 1/2 years now, I would definitely recommend running something more than a 30 amp fuse and 10 gauge wire, I tried that and it let me down in about a week (melted the fuse holder also). I would suggest at minimum 8 gauge wire and at least 40A fuse, I went a different route and used the internal 150A fuse at N3 and used a short 6 gauge jumper. With just the radio at half volume and heater fan wide open is about 31 amps.

Aux Battery Current.jpg
Here's what using an unfused jumper from N1 to N3 looks like. Like @MoparTH says, you are utilizing the existing 150A fuse instead of adding another fuse. If you are concerned about needing more capacity than a 40A or 50A N1 to N2 jumper, this is a good alternative. Keep in mind that just unplugging the control cable from the PCR (so it doesn't activate) does the same thing. Unplugging the PCR eliminates the need for any jumper.
n1 to n3 jumper.PNG
 

Rubi

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Here's what using an unfused jumper from N1 to N3 looks like. Like @MoparTH says, you are utilizing the existing 150A fuse instead of adding another fuse. If you are concerned about needing more capacity than a 40A or 50A N1 to N2 jumper, this is a good alternative. Keep in mind that just unplugging the control cable from the PCR (so it doesn't activate) does the same thing. Unplugging the PCR eliminates the need for any jumper.
n1 to n3 jumper.PNG
Jerry/Andy,

Thanks Andy for the excellent overview of the entire problem and complete circuit function analysis. Thanks to Jerry's many posts on this entire thread, with all the circuit maps and schematics; I was fine with my upcoming circuit mods concerning the removal of the aux battery and the additional circuit connections required. That was until I read Andy's post concerning the complete lockdown possibility if the circuit mods didn't recreate the correct power flow through the system. Once the vehicle goes into lockdown it would have to be towed to the dealer for a reflash.

I'm worried with the need to bring the Jeep to my local dealer; they don't seem to be up to par on what the Jeep enthusiasts of the world are doing to their vehicles. They had no knowledge of the TSB concerning the update to the 2019 ESS operating level when I spoke to them the other day.

I understand, more or less, how the system works, the aux battery removal and the addition of a jumper redirecting power from the main battery. What I ultimately want to do is set up my '18 JL Rubicon to Jerry's stripped wiring diagram with both power leads coming off the main battery to N1 & N2. I would have to cut off the old aux battery cable clamp and solder a large enough connector eyelet to somehow connect it to the main battery. As I stated in my original post; I'm concerned with the complete independence from or removal of the PCR with the associated connection to N3 causing my Jeep to go into lockdown.

I've been contemplating to just connect N1 to N3 with a 6 AWG soldered eyelets and leaving the PCR in place connected to N3. I have ESS disabled, so my thinking is this should satisfy my goal to remove the aux battery. But, I did say above; my ultimate goal was to simplify the system and connect both power leads from the main battery to N1 & N2 with the complete removal of the PCR. So the ultimate question, do you guys absolutely know if this will cause my Jeep to go into lockdown? If this is the case, lockdown, I will just do the 6 AWG connection between N1 & N3 and leave the PCR connected to N3 and in the vehicle.

Thanks again to both of you guys with help on this topic. It will also go a long way to clarify this procedure to any other people reading this post in the future.
 

Gee-pah

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@Rubi, hey. I don't want to be nick picky here but I will act that way just the same so concepts are understood. We are not redirecting power from the main battery. We are redirecting power normally supplied by the ESS battery to allow the main battery to supply it.

~~~~~~~~~~~~~~~~~~~~
You want to remove the ESS/Aux battery from play--possibly remove it physically. You don't run ESS, and you don't want this small battery possibly draining power from the main power, should the small battery become defective--which is exactly what can happen when two batteries are connected in parallel, as they are in the 3.6L, 99.99% of the time.

Right?

But you recognize that N1, which is normally connected to the ESS/Aux batteries positive terminal needs to see power for the 3.6L to run without idiot lights flashing, right? In fact in an 2018 3.6L that isn't flashed, no power on N1 will strand the vehicle from even attempting a crank.

So we need to redirect all calls for power from the ESS battery to the main battery. (I.e. we want the main battery to supply the power that would normally come from the ESS battery, in addition to the power that would come from calls made to the main battery.)

One way to do that is to somehow connect the battery cable that leads from N1 to the ESS battery's positive terminal back to the main battery's positive terminal, as you describe, but another far easier way to do this is to jumper N1 to N2.

Again, N1 is your ESS battery positive terminal, and N2 is your main battery positive terminal...all the time, no exceptions.

Are you worried that if you fuse this jumpering at 40 amps that it won't be enough?

Doing this step alone connects both batteries in parallel all the time. You seem worried about the relay at N3; you want to bypass it. Well we are about to take one more step that will render that relay's state, whether connected or not, or even if that relay is operating correctly, I believe moot.

The second step is we yank the connection of the cable that leads from the negative terminal of the ESS battery off the main battery's negative terminal.

This takes the ESS battery out of of the electric schematic. It won't be charged, it won't tax the main battery, and it can be removed if you like.

Game over.

N3 connects to a relay which connects to....electrical speaking....nothing. You are independent of it. It's status, whether it even works correctly are moot at this point.

Let me literally draw that for you in narrative form. N3 connects to a relay which connects to the positive terminal of the ESS battery, which flows though the ESS battery's juices to the negative terminal of the ESS battery, which is connected to .... nothing.

Rubi, an analogy...I build a simple flashlight for you that's illuminated.

You then ask me to add a switch to it that allows it to turn on and off that switch ( that is the relay on N3)--a switch you usually leave in the on state (just like the 3.6L does as it's a normally closed relay.) I add this switch for you but also disconnect the wire that leads from the flashlight's "D" cell battery's negative post to the flashlight (this is yanking the ESS negative cable from the main battery's negative post.)

Under no circumstances does the flashlight work now (is the ESS battery taxed). The switch I added becomes moot. Its on or off state, let alone its state of repair is of no consequence.

But you want that flashlight to illuminate (the JL to work.) Don't worry, I connected flashlight to another battery (the main battery. by taking the wire that normally connects to the top of the "D" cell battery, i.e. N1, and redirecting it to the positive post of another (the main) battery, a.k.a. N2.)

That relay: still moot.

Are you worried that you are going to blow that jumpered fuse between N1 and N2? Are you worried that the relay at N3, which connects now to nothing, might fail you?

@Rubi, I'm not sure what lockdown is by your definition. I think it is a 2018 3.6L JL that isn't flashed, that sees no power on N1, and doesn't even attempt a crank as a result because it thinks the ESS battery is dead.

Using the above, your N1 is going to see power as long as the main battery has power because you've hooked it to N2, which is the main battery's positive terminal.

Perhaps it is me who is missing something here. If so, apologies.
 

TroyBoy

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Rubi

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@Rubi, hey. I don't want to be nick picky here but I will act that way just the same so concepts are understood. We are not redirecting power from the main battery. We are redirecting power normally supplied by the ESS battery to allow the main battery to supply it.

~~~~~~~~~~~~~~~~~~~~
You want to remove the ESS/Aux battery from play--possibly remove it physically. You don't run ESS, and you don't want this small battery possibly draining power from the main power, should the small battery become defective--which is exactly what can happen when two batteries are connected in parallel, as they are in the 3.6L, 99.99% of the time.

Right?

But you recognize that N1, which is normally connected to the ESS/Aux batteries positive terminal needs to see power for the 3.6L to run without idiot lights flashing, right? In fact in an 2018 3.6L that isn't flashed, no power on N1 will strand the vehicle from even attempting a crank.

So we need to redirect all calls for power from the ESS battery to the main battery. (I.e. we want the main battery to supply the power that would normally come from the ESS battery, in addition to the power that would come from calls made to the main battery.)

One way to do that is to somehow connect the battery cable that leads from N1 to the ESS battery's positive terminal back to the main battery's positive terminal, as you describe, but another far easier way to do this is to jumper N1 to N2.

Again, N1 is your ESS battery positive terminal, and N2 is your main battery positive terminal...all the time, no exceptions.

Are you worried that if you fuse this jumpering at 40 amps that it won't be enough?

Doing this step alone connects both batteries in parallel all the time. You seem worried about the relay at N3; you want to bypass it. Well we are about to take one more step that will render that relay's state, whether connected or not, or even if that relay is operating correctly, I believe moot.

The second step is we yank the connection of the cable that leads from the negative terminal of the ESS battery off the main battery's negative terminal.

This takes the ESS battery out of of the electric schematic. It won't be charged, it won't tax the main battery, and it can be removed if you like.

Game over.

N3 connects to a relay which connects to....electrical speaking....nothing. You are independent of it. It's status, whether it even works correctly are moot at this point.

Let me literally draw that for you in narrative form. N3 connects to a relay which connects to the positive terminal of the ESS battery, which flows though the ESS battery's juices to the negative terminal of the ESS battery, which is connected to .... nothing.

Rubi, an analogy...I build a simple flashlight for you that's illuminated.

You then ask me to add a switch to it that allows it to turn on and off that switch ( that is the relay on N3)--a switch you usually leave in the on state (just like the 3.6L does as it's a normally closed relay.) I add this switch for you but also disconnect the wire that leads from the flashlight's "D" cell battery's negative post to the flashlight (this is yanking the ESS negative cable from the main battery's negative post.)

Under no circumstances does the flashlight work now (is the ESS battery taxed). The switch I added becomes moot. Its on or off state, let alone its state of repair is of no consequence.

But you want that flashlight to illuminate (the JL to work.) Don't worry, I connected flashlight to another battery (the main battery. by taking the wire that normally connects to the top of the "D" cell battery, i.e. N1, and redirecting it to the positive post of another (the main) battery, a.k.a. N2.)

That relay: still moot.

Are you worried that you are going to blow that jumpered fuse between N1 and N2? Are you worried that the relay at N3, which connects now to nothing, might fail you?

@Rubi, I'm not sure what lockdown is by your definition. I think it is a 2018 3.6L JL that isn't flashed, that sees no power on N1, and doesn't even attempt a crank as a result because it thinks the ESS battery is dead.

Using the above, your N1 is going to see power as long as the main battery has power because you've hooked it to N2, which is the main battery's positive terminal.

Perhaps it is me who is missing something here. If so, apologies.
My question of the PCR disconnection from N3 and removal of the PCR from my vehicle was more or less answered by you with your statement; as long as N1 is powered it will crank and not think the ESS battery is dead.

What I meant by "lockdown" is the inability of the vehicle to crank or start because it sees no power at N1. This would force me to have my vehicle towed to a dealer where they would have to do a reflash.

My reasoning of not wanting to jump N1 to N2 has nothing to do with the 40 amp fuse not being sufficient to handle the current load; there is nothing wrong with going this route. I like to keep things as simple and tidy as possible with the removal of unused components, ESS aux battery, PCR, when mods are accomplished. I just believe the most direct approach with the least amount of complication, is connecting the main battery to N1 & N2 as long as there are no cranking problems and dashboard code errors appearing from using this method.

Another step in this procedure we haven't talked about, I assume, the IBS would have to be unplugged as well? Thanks again for all your help and knowledge.
 

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FYI, you can move the aux battery cables up to the main battery without pulling the fuse box. You use the fender remove method and push/pull the cables.
https://www.jlwranglerforums.com/forum/threads/my-aux-delete-using-the-fender-remove-method.67539/
Thanks for this info. This is exactly what I was looking for in regards to removing the aux ESS battery and connecting the main to N1 & N2. I have my ESS disabled via the disconnection of the hood open/close switch, are you familiar with this tactic? I see from your other thread you used a Tazer to disable ESS. Just wondering if I kept my PCR intact if I would need to go the Tazer route.

I also see you have a '18 JLUR, have you had any dealer provided TSB updates before you removed the ESS battery and main battery reconnection?
 

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My question of the PCR disconnection from N3 and removal of the PCR from my vehicle was more or less answered by you with your statement; as long as N1 is powered it will crank and not think the ESS battery is dead.

What I meant by "lockdown" is the inability of the vehicle to crank or start because it sees no power at N1. This would force me to have my vehicle towed to a dealer where they would have to do a reflash.
If your 2018 3.6L JL lacks TSB 18-092-19 and no power is detected on N1 (normally the ESS battery), your vehicle will not even attempt a crank. Should a jumpstart be unable to get it going and the dealer services you they will detect this lack of power and deal with it by making sure your batteries are working and wired correctly.

Reflash:...???? Is it possible someone at the dealer might offer you TSB 18-092-19..I guess???? ($80+)

But I doubt many at dealerships realize that this flash, amog other things, changes the cold crank logic of a 2018 3.6L JL such that if no power is detected at N1, that upon the operator's second attempt to crank the vehicle, power is diverted to N2 (i.e. the main battery) and a crank is attempted off this main battery, that if successful, disables ESS until the next cold crank, if any, at which power is detected at N1.

My reasoning of not wanting to jump N1 to N2 has nothing to do with the 40 amp fuse not being sufficient to handle the current load; there is nothing wrong with going this route. I like to keep things as simple and tidy as possible with the removal of unused components, ESS aux battery, PCR, when mods are accomplished.
Sigh, @Rubi, I guess this is where we will have to agree to disagree. I too like to keep things as simple as possible, but to my way of thinking it involves the least amount of work that accomplishes the goal, while being able to easily revert the vehicle back to stock for the dealer so service warranty claims are not denied.

Tidy, another goal you aspire to, is often not simple nor consistent with putting the vehicle back to factory settings. It involves more work, and more work to put back the way it was.

@Rubi--you want simple...just get TSB 18-092-19 and change nothing under the hood. This flash will allow you to not be stranded if your ESS battery is dead but your main battery isn't, as described above.

But if you don't want to pay for the flash, or risk a bad ESS battery draining your main battery, then fuse N1 to N2, remove the cable on the main battery that comes from the negative post of the ESS battery....

AND stop!.....at least for now. Get this working and stable for the time being.

and not because this is most tidy, but easiest to have you restore to factory for presentation to the dealer, or troubleshoot of problems arise.

@Rubi...I feel like I give you everything you need to do this, and you retort..."but I want to take it one step more."

....remove the IBS, remove the relay, remove the ESS battery, but it will be more work for you to put it back.

Alternatively, read https://www.jlwranglerforums.com/forum/threads/3-6l-ess-ibs-information.22585/

The IBS is there to determine of an ESS event should be attempted--in other words if the main battery has enough power to crank the vehicle after an ESS event. You're not going to run ESS anymore (right?) rendering this decision making moot.

After 6 cold cranks where your rig, with these changes (N1->N2 and yanking the aforementioned cable) is going to detect identical voltages in what it thinks is the ESS battery (which thanks to these changes is now your main battery), and your....

wait for it...

main battery, it is going to disable ESS anyway. I know people have reported issues with their IBS on the forum, but why yank parts that are harder to put back which no longer play a role in the operation of your vehicle?

Again, at least initially, leave them be and pull one at a time if you must.

I just believe the most direct approach with the least amount of complication, is connecting the main battery to N1 & N2 as long as there are no cranking problems and dashboard code errors appearing from using this method.
Then @Rubi, this path isn't for you. And I say this because after 6 cold cranks using the two steps I gave you, your ESS is going to get disabled by the vehicle as it detects identical voltages on the main battery and the--what it thinks is the ESS battery---which as stated--is now the main battery due to your 1) N1->N2 jumper and 2) removal of the aforementioned negative cable.

Then again, this 6 cold crank issue is no different than those faced by owners who put into place the Genesis system, unless you refer to Jerry's post https://www.jlwranglerforums.com/forum/threads/3-6l-ess-aux-battery-bypass.17293/post-1499836 where he talks about how @SpookyXJ keeps ESS on with the Genesis system.

If you truly want no ESS battery, no ESS, and no diagnostic codes then buy tech to turn off ESS, jumper N1->N2 and disconnect the aforementioned cable, and incorporate @SpookyXJ's logic somehow to show the rig (I assume, I haven't read it) that there are two batteries with different voltages.

Another step in this procedure we haven't talked about, I assume, the IBS would have to be unplugged as well?
@Rubi, please leave the IBS alone for now. Its purpose, as discussed above is to determine if enough power exists in the main battery to take the 3.6L into ESS mode at a stop light. The wiring I've advised you to do is going to disable ESS after 6 cold cranks anyway, I would think, rendering the logic the IBS provides moot. Jerry can speak more to this than me.

@Rubi: I feel we are running around in circles because I truly do not get what it is you want. If you give me your mission statement I can give you an answer:

Factors:

* I want to run 1 battery. I don't want the ESS battery to ever risk taxing the main battery.

* I want to not get disabled if my ESS battery dies, using the simplest approach even if that involves a dealer flash.

* I want no diagnostic lights being on in the dash that disables ESS, but I want ESS off.

* I want to be able to control all of this (in which case I'll point you to Jerry's wiring setup with on/off switches---which will offer more complexity but more control.)

* I want a clean hot rod setup with no unnecessary parts, even if it makes it harder for me to restore the rig to factory.

~~~~~~~~~~~

simply pick your priorities above, some are mutually exclusive, and I can guide you.

:)
 

Rubi

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If your 2018 3.6L JL lacks TSB 18-092-19 and no power is detected on N1 (normally the ESS battery), your vehicle will not even attempt a crank. Should a jumpstart be unable to get it going and the dealer services you they will detect this lack of power and deal with it by making sure your batteries are working and wired correctly.

Reflash:...???? Is it possible someone at the dealer might offer you TSB 18-092-19..I guess???? ($80+)

But I doubt many at dealerships realize that this flash, amog other things, changes the cold crank logic of a 2018 3.6L JL such that if no power is detected at N1, that upon the operator's second attempt to crank the vehicle, power is diverted to N2 (i.e. the main battery) and a crank is attempted off this main battery, that if successful, disables ESS until the next cold crank, if any, at which power is detected at N1.



Sigh, @Rubi, I guess this is where we will have to agree to disagree. I too like to keep things as simple as possible, but to my way of thinking it involves the least amount of work that accomplishes the goal, while being able to easily revert the vehicle back to stock for the dealer so service warranty claims are not denied.

Tidy, another goal you aspire to, is often not simple nor consistent with putting the vehicle back to factory settings. It involves more work, and more work to put back the way it was.

@Rubi--you want simple...just get TSB 18-092-19 and change nothing under the hood. This flash will allow you to not be stranded if your ESS battery is dead but your main battery isn't, as described above.

But if you don't want to pay for the flash, or risk a bad ESS battery draining your main battery, then fuse N1 to N2, remove the cable on the main battery that comes from the negative post of the ESS battery....

AND stop!.....at least for now. Get this working and stable for the time being.

and not because this is most tidy, but easiest to have you restore to factory for presentation to the dealer, or troubleshoot of problems arise.

@Rubi...I feel like I give you everything you need to do this, and you retort..."but I want to take it one step more."

....remove the IBS, remove the relay, remove the ESS battery, but it will be more work for you to put it back.

Alternatively, read https://www.jlwranglerforums.com/forum/threads/3-6l-ess-ibs-information.22585/

The IBS is there to determine of an ESS event should be attempted--in other words if the main battery has enough power to crank the vehicle after an ESS event. You're not going to run ESS anymore (right?) rendering this decision making moot.

After 6 cold cranks where your rig, with these changes (N1->N2 and yanking the aforementioned cable) is going to detect identical voltages in what it thinks is the ESS battery (which thanks to these changes is now your main battery), and your....

wait for it...

main battery, it is going to disable ESS anyway. I know people have reported issues with their IBS on the forum, but why yank parts that are harder to put back which no longer play a role in the operation of your vehicle?

Again, at least initially, leave them be and pull one at a time if you must.



Then @Rubi, this path isn't for you. And I say this because after 6 cold cranks using the two steps I gave you, your ESS is going to get disabled by the vehicle as it detects identical voltages on the main battery and the--what it thinks is the ESS battery---which as stated--is now the main battery due to your 1) N1->N2 jumper and 2) removal of the aforementioned negative cable.

Then again, this 6 cold crank issue is no different than those faced by owners who put into place the Genesis system, unless you refer to Jerry's post https://www.jlwranglerforums.com/forum/threads/3-6l-ess-aux-battery-bypass.17293/post-1499836 where he talks about how @SpookyXJ keeps ESS on with the Genesis system.

If you truly want no ESS battery, no ESS, and no diagnostic codes then buy tech to turn off ESS, jumper N1->N2 and disconnect the aforementioned cable, and incorporate @SpookyXJ's logic somehow to show the rig (I assume, I haven't read it) that there are two batteries with different voltages.



@Rubi, please leave the IBS alone for now. Its purpose, as discussed above is to determine if enough power exists in the main battery to take the 3.6L into ESS mode at a stop light. The wiring I've advised you to do is going to disable ESS after 6 cold cranks anyway, I would think, rendering the logic the IBS provides moot. Jerry can speak more to this than me.

@Rubi: I feel we are running around in circles because I truly do not get what it is you want. If you give me your mission statement I can give you an answer:

Factors:

* I want to run 1 battery. I don't want the ESS battery to ever risk taxing the main battery.

* I want to not get disabled if my ESS battery dies, using the simplest approach even if that involves a dealer flash.

* I want no diagnostic lights being on in the dash that disables ESS, but I want ESS off.

* I want to be able to control all of this (in which case I'll point you to Jerry's wiring setup with on/off switches---which will offer more complexity but more control.)

* I want a clean hot rod setup with no unnecessary parts, even if it makes it harder for me to restore the rig to factory.

~~~~~~~~~~~

simply pick your priorities above, some are mutually exclusive, and I can guide you.

:)
You made some very valid points; especially the one concerning putting it back to fully stock form for warranty work. Makes sense to do the fuseable link between N1 & N2 then disconnect the negative lead from the ESS battery.

I will leave it mostly stock, add the N1 to N2 jumper with the negative cable lead from the ESS disconnected. Also get the TSB reflash 18-092-19. Thanks for all your help.
 
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