Stop/Start Not Ready-Battery Charging

[JeepAustinWeird]

If I understand basics here, Alternators basically function to charge the battery and to power the electrical system when engine is running.
Probably like several here, I am not too fond of my engine shutting down most every time I come to a stop, so I have typically turned this lovely feature off after starting my Jeep.

Not sure if this question has been asked so I apologize if it has....Is it possible that when the ESS system is turned off (ie button pressed on dash), somehow this shuts off the ability of the alternator to regenerate charge for the Aux Battery, and maybe that is why myself or others that do this have experienced problems with ESS not ready, battery charging messages or similar. I realize that there are probably others that don't turn off their ESS system on startup and have had the problem, and that Jeep may have produced or procured bad batteries, but can turning off the ESS system actually lead to development of battery problems?

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[ThirtyOne]

If I understand basics here, Alternators basically function to charge the battery and to power the electrical system when engine is running.
Probably like several here, I am not too fond of my engine shutting down most every time I come to a stop, so I have typically turned this lovely feature off after starting my Jeep.

Not sure if this question has been asked so I apologize if it has....Is it possible that when the ESS system is turned off (ie button pressed on dash), somehow this shuts off the ability of the alternator to regenerate charge for the Aux Battery, and maybe that is why myself or others that do this have experienced problems with ESS not ready, battery charging messages or similar. I realize that there are probably others that don't turn off their ESS system on startup and have had the problem, and that Jeep may have produced or procured bad batteries, but can turning off the ESS system actually lead to development of battery problems?

You might be on to something. I used ESS regularly, until a had another issue that caused it to disable (for about a month). Ever since that issue was fixed, ESS never worked right again.

 

[WranglerMan]

If I understand basics here, Alternators basically function to charge the battery and to power the electrical system when engine is running.
Probably like several here, I am not too fond of my engine shutting down most every time I come to a stop, so I have typically turned this lovely feature off after starting my Jeep.

Not sure if this question has been asked so I apologize if it has....Is it possible that when the ESS system is turned off (ie button pressed on dash), somehow this shuts off the ability of the alternator to regenerate charge for the Aux Battery, and maybe that is why myself or others that do this have experienced problems with ESS not ready, battery charging messages or similar. I realize that there are probably others that don't turn off their ESS system on startup and have had the problem, and that Jeep may have produced or procured bad batteries, but can turning off the ESS system actually lead to development of battery problems?

Very doubtful this is the case, I have used a Tazer in the past and currently use a Smart Stop/Start module to control ESS, the SSS module basically remembers the last state ESS was in and in my case I have it off all the time, I have been running this way ( ESS Off ) for over two years and the only issue I had was after about 7 months the main battery crapped out and was replaced under warranty.

I purchased my JLUS late 2017 and no issues with the batteries other than the main crapping out as I mentioned, I do put my JL on a battery tender once a month as it sits a lot so maybe that helps keep the batteries healthy but once the baby battery craps out it’s doubtful I will replace and it will give me a chance to see how my bypass jumper works long term.

Like I have said over and over, I honestly don’t care it has two batteries but the idiot engineers could have placed the ESS battery in a better place.

 

[willcasp]

A few weeks ago, the dealer replaced my AUX battery to resolve the issue. This worked for about a week. I been stuck in the ESS disabled, recharging battery mode every since.
When this Coronovirus stuff lifts, I will contact my dealer for a second time to service this emissions feature.

 

[jludave]

When this Coronovirus stuff lifts, I will contact my dealer for a second time to service this emissions feature.

Your dealership should still be open for service. Auto repair shops have been deemed essential and can remain open. Sales/showrooms on the other hand will be closed. Of course, it's your call as to whether or not you'd want to go in at this time. Good luck and stay safe!

 

[Adam 4248]

My dealer said my ESS battery is not getting a charge. I sometimes turn mine off, but usually leave it on. Whether disabled or not, the aux battery should be charging while the engine is running. What, or where, is the device that separates the aux battery, electrically, from the main battery? Can they be jumped together without overcharging the aux battery? Perhaps with an aux voltage regulator?

 

[willcasp]

My dealer said my ESS battery is not getting a charge. I sometimes turn mine off, but usually leave it on. Whether disabled or not, the aux battery should be charging while the engine is running. What, or where, is the device that separates the aux battery, electrically, from the main battery? Can they be jumped together without overcharging the aux battery? Perhaps with an aux voltage regulator?

There are several really good threads in these forums on how this hook up works, and how it can by bypassed. Do a quick search. Here is one of them: https://www.jlwranglerforums.com/forum/threads/3-6l-ess-aux-battery-bypass.17293/

 

[Jebiruph]

My dealer said my ESS battery is not getting a charge. I sometimes turn mine off, but usually leave it on. Whether disabled or not, the aux battery should be charging while the engine is running. What, or where, is the device that separates the aux battery, electrically, from the main battery? Can they be jumped together without overcharging the aux battery? Perhaps with an aux voltage regulator?

The aux battery connects to the alternator through one of the high capacity fuses. Careless placement of the disconnected positive battery cable will blow the fuse.

 

[SteadyC]

I’m reading quite a lot of incorrect information in this thread, and recommend everyone read the link that willcasp posted. When the dash says, ESS not ready charging battery, it’s talking about the main cranking battery, not the aux battery. The aux battery isn’t used for starting the engine. It is used to power the interior electronics, lights, wipers, etc. when the engine isn’t running during ESS. The aux battery is not measured or tested by the vehicle for battery level as part of ESS, only the main cranking battery. If it doesn’t have enough charge, the ESS won’t engage, to prevent the situation that the Jeep won’t start in traffic.

 

[Adam 4248]

There are several really good threads in these forums on how this hook up works, and how it can by bypassed. Do a quick search. Here is one of them: https://www.jlwranglerforums.com/forum/threads/3-6l-ess-aux-battery-bypass.17293/

Thank you for the link. I have read that before, guess I needed to re-read it.

 

[Adam 4248]

The aux battery connects to the alternator through one of the high capacity fuses. Careless placement of the disconnected positive battery cable will blow the fuse.

Thanks, I understand. My diesel Ram Mega Cab has two full size batteries, got to be careful..

My dealer said my aux battery was bad, and replaced it, but said the new aux battery is not charging. So, if the aux battery is good/new, but is not charging, could the jumper wire be used to charge the aux battery, if the aux negative remained connected?

 

[Adam 4248]

The aux battery connects to the alternator through one of the high capacity fuses. Careless placement of the disconnected positive battery cable will blow the fuse.

Many years ago a friend of mine was working on his car, while wearing a watch with a metal wristband. He accidentally grounded his wristband b/t the alternator output stud and the exhaust manifold... instant burn all the way around his wrist!

 

[Jelllo]

I’m reading quite a lot of incorrect information in this thread, and recommend everyone read the link that willcasp posted. When the dash says, ESS not ready charging battery, it’s talking about the main cranking battery, not the aux battery. The aux battery isn’t used for starting the engine. It is used to power the interior electronics, lights, wipers, etc. when the engine isn’t running during ESS. The aux battery is not measured or tested by the vehicle for battery level as part of ESS, only the main cranking battery. If it doesn’t have enough charge, the ESS won’t engage, to prevent the situation that the Jeep won’t start in traffic.

You are incorrect. I don't have all the details but there is a Star case on the problem, and it is related only to the aux battery not charging properly. It states to charge the aux battery for 6 hours. On another note users here have removed the main battery and the Jeep still starts, so obviously both batteries are used for starting.

 

[SteadyC]

You are incorrect. I don't have all the details but there is a Star case on the problem, and it is related only to the aux battery not charging properly. It states to charge the aux battery for 6 hours. On another note users here have removed the main battery and the Jeep still starts, so obviously both batteries are used for starting.

No, that is incorrect. The aux battery can be used for starting, as a backup only, and only by manually bypassing the main battery, as you have noted is done in your example, removing the main battery. During ESS (the topic of this thread) the main cranking battery is used for starting, and only main cranking battery, no question here. Do some more reading from:
https://www.jlwranglerforums.com/forum/threads/3-6l-ess-dual-battery-consolidated-information.25377/
On a properly operating system, the batteries are always connected in parallel through the PCR except during an ESS auto stop. (Topic of this thread). They are disconnected during a ESS and thus only one is starting.

your example (which isn’t ESS related) A dead main battery should be disconnected from the system before attempting to start from the reconnected aux battery. The aux battery should also be load tested and fully charged before relying on it as a dedicated reserve battery.

https://www.jlwranglerforums.com/fo...-anyone-with-issues.45582/page-9#post-1039814

You can't have ESS without an IBS. The ESS system relies on the IBS to provide accurate information on the health of the cranking battery to determine if the cranking battery can power a restart before ESS is enabled.

this is why you see ESS is disabled battery charging, the IBS is detecting the main cranking battery is not fully charged, and thus doesn’t use ESS. The IBS does not measure the aux battery.
https://www.jlwranglerforums.com/fo...-anyone-with-issues.45582/page-8#post-1038181
The IBS measures current into and out of the single battery it is connected to and knows nothing about some giant virtual battery. It has no way of measuring the current into and out of the second battery. This is different than monitoring the voltage of the batteries.

bottom line, to fix ESS is disabled recharging battery, replace the main cranking battery, ensure it is charged, and you are done. If you would like to replace the aux battery at the same time, not a bad idea while you are there, but not required for this specific issue.

on the flip side, the aux is tested during cold start by PCR, if the aux battery fails the test, the Jeep may not start. This is then where bypassing the aux battery (three ways to do this, jumping N1 and N2, using a battery jumper with possible more charge time required to get the aux to pass the startup test or with aux bypassed, or disconnecting negative on PCR) can get you started. It appears that Jeep has updated this on newer Jeeps, and won’t fail to start when testing a bad aux battery, so that is good news for 2020 Jeeps.

 

[Jelllo]

bottom line, to fix ESS is disabled recharging battery, replace the main cranking battery, ensure it is charged, and you are done. If you would like to replace the aux battery at the same time, not a bad idea while you are there, but not required for this specific issue.

I just had my Jeep at the dealer for this problem and they stated it was the aux battery not charging properly and that is what the tech wrote on the repair order. I can provide a copy if you don't believe it.

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