Aux Battery Problems

[darkstar13]

I haven't really had any problems.

When I first picked up the Gladiator, I started collecting a few upgrade items, winch aux switches ( aftermarket), and freezer. I started with the S-Tech aux switches. I disconnected the main battery connection at the post. I started working o the install under the hood. I made a bracket for a circuit breaker. This took some time. It was the next day when I finished the install. I hooked up the main neg on the post and jumped in the drivers seat. Everything looked and acted normal until I went to start. I got flicker lights and a no crank. Second attempt was the same.

Found the Gladiator Forum!

Now realizing that I had two batteries and that I completely killed the aux, I separated both negatives and removed the geound at the fender. I then charged the aux battery over night and surprisingly it came back to life and tested good. I then charged the main battery. I had a few weeks of the battery charging message.

Back to the Gladiator Forum!

There I found Mr. Bill and ShadowsPapa's threads on ESS. Others contributed to the thread as well but those two I can recall .

I charged both batteries now with an AGM charger and reset the IBS. I haven't had any issues since. I do notice that if the JT sits for over a week my ESS battery charging message will remain on for a longer period of time. When that happens I plug in my NOCO charger.

I have used both this forum and way back 2012 the JK forum was my bible. I did put everything back in my JT ( except the AUX battery) and the Negative cable connections. The vehicle ran fine. I wanted to check N1 N2 & n3 in this setup as you explained earlier. I had source voltage at N3, I had source voltage at both N2 &n1. I then disconnected the AUX positive from the MAIN batteery and the vehicle immediately shut down. I checked N1 with the AUX + off NO voltage, N2 source voltage, N3 no voltage. back . It madeno dif with the F42 in or out.

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[Lost1wing]

When you removed the Aux+ from the Main+, you had nothing powering N1. Normally if the pcr and your N3 fuse was good you would not have lost power at N1. N1 would have been powered from the main battery via the pcr and N3 fuse. I believe you N3 is blown.

Before going out and spending all that money on a new fuse array, do what jaxmax suggested and remove your connection at N3 and ohm out the N3 fuse.

 

[Lost1wing]

Leave F42 fuse pulled for now. Do you have a volt meter and are all the wires off N-3 now? If no wire on there put meter between N-3 and ground wires on fender and you get no reading you probably have a blown fuse, having N-1 which goes to senisitive electronics unfused very long is not a good idea.
You need to be aware of the simple circuit involved with Aux battery and the PCR , N-3 takes fused main battery power down to the PCR to one side, on the other side of this "switch" is terminated N-1 which feeds the electronics and also the Aux battery positive, so during a s ESS event the PCR opens disconnecting main battery power from electronics but Aux battery is still connected. You could have just pulled the wires off N-1 and N-3 and PUT A JUMPER BETWEEN N-1 AND N-3 if your fuse is good, instead of going back down to the battery with another wire. Don't put the jumper between N-1 and N-2 , I think you are getting it that it's unfused then. I would check carefully to see if you have a blown fuse that is an expensive repair I believe.....Jack

N2 is unfused. N1 is unfused. The power distribution center has fuses for the individual circuits. When the Aux is tied in to N2, the only concern with fuses would be the 150 amp N3. What is the 150amp fuse for? Perhaps to save the main battery if the aux battery internally shorts out. In the OPs case where he bypassed the pcr and N3, he simply sent the power through the backdoor. The individual circuit are still fused.

As far as testing N3, you are correct. With N3 cable off of the terminal he can check for power at N3. If no power at N3, verify power at N2. If that is the case, bad N3. He needs to be careful of where that N3 cable goes it should be live.

 

[darkstar13]

Leave F42 fuse pulled for now. Do you have a volt meter and are all the wires off N-3 now? If no wire on there put meter between N-3 and ground wires on fender and you get no reading you probably have a blown fuse, having N-1 which goes to senisitive electronics unfused very long is not a good idea.
You need to be aware of the simple circuit involved with Aux battery and the PCR , N-3 takes fused main battery power down to the PCR to one side, on the other side of this "switch" is terminated N-1 which feeds the electronics and also the Aux battery positive, so during a s ESS event the PCR opens disconnecting main battery power from electronics but Aux battery is still connected. You could have just pulled the wires off N-1 and N-3 and PUT A JUMPER BETWEEN N-1 AND N-3 if your fuse is good, instead of going back down to the battery with another wire. Don't put the jumper between N-1 and N-2 , I think you are getting it that it's unfused then. I would check carefully to see if you have a blown fuse that is an expensive repair I believe.....Jack

Fluked N1 to ground = NO VDC (F42 disconnected

N2 is unfused. N1 is unfused. The power distribution center has fuses for the individual circuits. When the Aux is tied in to N2, the only concern with fuses would be the 150 amp N3. What is the 150amp fuse for? Perhaps to save the main battery if the aux battery internally shorts out. In the OPs case where he bypassed the pcr and N3, he simply sent the power through the backdoor. The individual circuit are still fused.

As far as testing N3, you are correct. With N3 cable off of the terminal he can check for power at N3. If no power at N3, verify power at N2. If that is the case, bad N3. He needs to be careful of where that N3 cable goes it should be live.

With F 42 pulled N1 = source voltage, N2= source voltage & N3= no VDC

 

[Lost1wing]

That would explain your symptoms in your original post and why tieing back your Aux - and pulling f42 didn't work. Your main battery was not able to pass through N3 to feed the N1. When you relocated your Aux + to your main +, you now had power at N1 and N2 bypassing the pcr and N3.

Time for a new fuse array. That is if you care to put it back close to normal.

Your purpose to do the Aux delete was just to eliminate the extra cost of the aux because it was going bad? I know you wanted to go with a Genisis dual battery setup for overlanding, but I though that you can leave the aux still in the system. I have not looked at that option for myself.

 

[sharpsicle]

Not to confuse anyone on the subject of ESS, sharpsicle you are correct on the purpose of the aux battery. I think there was some discussion on when the pcr actually opens and how long it remains open. From what I remember reading, is that the pcr is actually closed during an ess start letting the aux assist the main.

It is closed while the engine is off, but it opens very briefly during the actual start event. This is designed to maintain consistent voltage across the batteries while at rest, but when it comes time to actually crank the starter, they separate to maintain voltage for the computers.

When trying to maintain consistent voltage to one area (A) during a high-draw event from another area (B), the last thing you'd want is two batteries together. They'd both drop together (granted less, but still drop). Not separating would negate the entire point of a 2nd battery as you'd just use one bigger one to get the same results. So, when it's cranking during ESS restarts, they split and one powers area A and the other area B.

 

[Lost1wing]

It is closed while the engine is off, but it opens very briefly during the actual start event. This is designed to maintain consistent voltage across the batteries while at rest, but when it comes time to actually crank the starter, they separate to maintain voltage for the computers.

When trying to maintain consistent voltage to one area during a high-draw event from another area, the last thing you'd want is two batteries together. They'd both drop together (granted less, but still drop). It would negate the entire point of a 2nd battery as you'd just use one bigger one. So, when it's cranking during ESS restarts, one powers area A and the other area B.

I'm with you on that. I believe the thinking early on was that during a ESS stop only the Aux was powering the computers until until after the engine is restarted. The discussion on this forum states that the two batteries are always in parallel except for starter engagement. Then it got deeper and I tuned out. Quotes were flying from the service manual. ShadowsPapa did some testing of his own showing how the batteries appeared to remain in parallel on the oscilloscope.

 

[darkstar13]

That would explain your symptoms in your original post and why tieing back your Aux - and pulling f42 didn't work. Your main battery was not able to pass through N3 to feed the N1. When you relocated your Aux + to your main +, you now had power at N1 and N2 bypassing the pcr and N3.

Time for a new fuse array. That is if you care to put it back close to normal.

Your purpose to do the Aux delete was just to eliminate the extra cost of the aux because it was going bad? I know you wanted to go with a Genisis dual battery setup for overlanding, but I though that you can leave the aux still in the system. I have not looked at that option for myself.

I pulled the Z array (it looked so easy but was not). I did disconnect the entire Main Negative post. I then pulled the "Z" array ohmed it and all were 0.2/0.3 K but N3 =OL. Again I wholeheartedly appreciate all the time spent helping me get to the correct solution. This goes out to all who imparted their expertise on me. I have learned a lot. I intend to follow up once I figure out my next move. I would like the Genesis system but just don't think it will fit along with the Procharger supercharger. Plus I figure about $1900 or so with 2 new batteries (Genesis). So I may just go buy the Bigger H7 ( I believe that is OEM for me {850CCA}and the 14 aux [220 CCA]extreme. This one lasted 5 + years and I see the daises starting to grow. Now that YOU and Sharpsycle , Jaxmax, KQL, Hootbro, Mr._Bill, Jebiruph and grein46080 have got me on a roll ( I hope) I may just get the 2 new batteries (same type each), reconnect the cables very carefully, reinstall the F 42 fuse (last), do not hook up any negative cables to the MAIN until all is complete. Thanks forum members! Ray

 

[Lost1wing]

I pulled the Z array (it looked so easy but was not). I did disconnect the entire Main Negative post. I then pulled the "Z" array ohmed it and all were 0.2/0.3 K but N3 =OL. Again I wholeheartedly appreciate all the time spent helping me get to the correct solution. This goes out to all who imparted their expertise on me. I have learned a lot. I intend to follow up once I figure out my next move. I would like the Genesis system but just don't think it will fit along with the Procharger supercharger. Plus I figure about $1900 or so with 2 new batteries (Genesis). So I may just go buy the Bigger H7 ( I believe that is OEM for me {850CCA}and the 14 aux [220 CCA]extreme. This one lasted 5 + years and I see the daises starting to grow. Now that YOU and Sharpsycle , Jaxmax, KQL, Hootbro, Mr._Bill, Jebiruph and grein46080 have got me on a roll ( I hope) I may just get the 2 new batteries (same type each), reconnect the cables very carefully, reinstall the F 42 fuse (last), do not hook up any negative cables to the MAIN until all is complete. Thanks forum members! Ray

Save the installation of the fender ground for last. Don't forget to unplug the IBS sensor connector and plug it back in when you are done. Good luck!

 

[darkstar13]

Save the installation of the fender ground for last. Don't forget to unplug the IBS sensor connector and plug it back in when you are done. Good luck!

Thanks again for all assistance. I will follow up. One last thing I was leaning toward odessey batteries as they make a combo. Do you have a strong allegiance toward any particular brand. I used to buy X-2 from batteries plus.

 

[Lost1wing]

Thanks again for all assistance. I will follow up. One last thing I was leaning toward odessey batteries as they make a combo. Do you have a strong allegiance toward any particular brand. I used to buy X-2 from batteries plus.

I'm an interstate battery fan. I have a fleet of personal vehicles and equipment. Walmart batteries have let me down in the past. My friend uses Odessey batteries in his Jeeps. He never complains about battery issues. I just have too many uses for batteries to justify the expense of Odessey batteries.

 

[Blade1668]

I am now up to speed on the "N" fuse array. I will purchase just in case. . Any recommendations for part? They seem to be pricey.

Amazon has it fairly cheap and fast shipping.

Been there recently myself. It fried the 150 amp. A lot of frustration with it. On top of vehicle shut on hwy loss of power steering, brakes trying to pull transmission release strap as disco of dashboard lights, wipers in traffic. If I would have seen a Jeep engineer who developed that s### I would have beat him to death on the spot. Likely would still want to beat his ### today. Oh the warning was on way to buy replacement batteries. The "news flash" of bad battery was it stopped running at stop sign and a ESS even shut off and no restart.

Not trying to cost a sales for our resident Mopar contact here.

 

[darkstar13]

Thanks for the information. Unfortunately I have already ordered a couple from Mopar Wholesale parts. On this one I wanted OEM parts from MOPAR. I do thank you.

 

[Blade1668]

Thanks for the information. Unfortunately I have already ordered a couple from Mopar Wholesale parts. On this one I wanted OEM parts from MOPAR. I do thank you.

I ordered it since a week later a friend of mine had his fried when his battery failed parked in driveway. A 2020 Overland. Since both of us are Ret. best to keep on budget for expenses. At least myself, he's not overly concerned as I am.

 

[darkstar13]

My two thoughts after reading through all this:

1. With how you have it set up now, make sure you disable the ESS system at every start, or have something that remembers the last state for you. You do not want ESS active on just the main battery, as the voltage drop from a start event may cause the computers to reboot, leaving you stuck in the road. This is the whole point of the aux battery's existence.
2. This really seemed like a lot of runaround just to not put in a new aux battery, but that's just me...

My intent was to evaluate a dual battery install vs a new AUX Battery install is why it "seemed" to a lot of run around to you and others who did not read all the post. But I appreciate your insights. Ray

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