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Battery story

wolfdog

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2018 JLUS, original batteies! ESS stopped working 2 years ago nothing to indicate, but no ESS, no annoying A anywhere! Great, didn't care, not fond of ESS so a bonus to me! Got a bit panicy though about Aux. battery about 4 months ago so disconnected it, pulled proper fuse F42 and disconnected neg aux wire. All went well still no indication of ESS existing, only problem was remote start stopped working? This should not have anything to do with Aux disconnect? Still pushing orig battery 6 years so probably low voltage, gauge volts still read 4.5V? However, being the great procrastinator I hang in with original main battery, bad idea! Well yesterday main batt. dead, I have AAA Jump start and off I go for a new main battery, I install and off to the races! Voltage on gauge 4.5V I assume as should be? Surprise, Remote start back in business, and unfortunately after 2 years or so, so is ESS!! Aux. battery neg. and F42 still disconnected!

Now, the next day new main showing 3.5V ??? After I installed it was at 4.5V for the day...not today? Anybody have idea?

Oh ya, now ESS back, as mentioned hasn't worked for 2 years, I have to shut off ESS each start, working off main of course Damn!! Wonder why after 2 years of ESS not working even with good (or was it?) Aux?

Go Jeep!!!
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One of the reasons the ESS may not have been working was low voltage on the main battery. There are many reason why the ESS won’t work, the low voltage is one of them. Removing the fuse and disconnecting the aux battery moves the ESS to the main battery. The new battery with the higher voltage probably was enough for the ESS to start working again.
 

TheNewGuy

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2018 JLUS, original batteies! ESS stopped working 2 years ago nothing to indicate, but no ESS, no annoying A anywhere! Great, didn't care, not fond of ESS so a bonus to me! Got a bit panicy though about Aux. battery about 4 months ago so disconnected it, pulled proper fuse F42 and disconnected neg aux wire. All went well still no indication of ESS existing, only problem was remote start stopped working? This should not have anything to do with Aux disconnect? Still pushing orig battery 6 years so probably low voltage, gauge volts still read 4.5V? However, being the great procrastinator I hang in with original main battery, bad idea! Well yesterday main batt. dead, I have AAA Jump start and off I go for a new main battery, I install and off to the races! Voltage on gauge 4.5V I assume as should be? Surprise, Remote start back in business, and unfortunately after 2 years or so, so is ESS!! Aux. battery neg. and F42 still disconnected!

Now, the next day new main showing 3.5V ??? After I installed it was at 4.5V for the day...not today? Anybody have idea?

Oh ya, now ESS back, as mentioned hasn't worked for 2 years, I have to shut off ESS each start, working off main of course Damn!! Wonder why after 2 years of ESS not working even with good (or was it?) Aux?

Go Jeep!!!
Bypassing/eliminating the AUX battery DOES NOT eliminate the ESS feature. It will just run off the main battery.
You either have to push the button, buy a device (such as SmartStopStart) that will make the button remember that it was set to off before the Jeep was shut off or disable ESS with a Tazer.
 

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I assume you mean 14.5/13.5V (not 4.5/3.5).

With the engine running, the voltage display on the dash reflects system voltage, which is effectively the alternator voltage (not resting battery voltage).

Alternator voltage higher than resting battery voltage creates electrical potential to charge the battery.

The dash voltage dropping to 13.5V is generally a good thing, an indicator the new battery is accepting charge. If it was pinned at 14.5V with the old battery, the alternator was likely struggling to charge the dying battery.
 

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I assume you mean 14.5/13.5V (not 4.5/3.5).

With the engine running, the voltage display on the dash reflects system voltage, which is effectively the alternator voltage (not resting battery voltage).

Alternator voltage higher than resting battery voltage creates electrical potential to charge the battery.

The dash voltage dropping to 13.5V is generally a good thing, an indicator the new battery is accepting charge. If it was pinned at 14.5V with the old battery, the alternator was likely struggling to charge the dying battery.
Those numbers made me think this was a troll post. Maybe it's not?

I've been watching mine recently. It's almost always at 14.0 and rarely fluctuates. When it does it just deviates by +/- 0.1 volt. I'm guessing the alternator is struggling.
 

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Moose568

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I just replaced my main battery and I wasn’t getting the correct voltage at the new battery terminals. I charged the new battery for a few hours and everything was fine.
 

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Those numbers made me think this was a troll post. Maybe it's not?

I've been watching mine recently. It's almost always at 14.0 and rarely fluctuates. When it does it just deviates by +/- 0.1 volt. I'm guessing the alternator is struggling.
In my experience (assuming temperate ambient conditions), 14.0V +/- a couple tenths is normal post startup for a healthy battery at a reasonable state of charge. If/when voltage drops is less clear to me.

Anything above 14.4V for a sustained period in normal temperatures, I'd test my battery.
 

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In my experience (assuming temperate ambient conditions), 14.0V +/- a couple tenths is normal post startup for a healthy battery at a reasonable state of charge. If/when voltage drops is less clear to me.

Anything above 14.4V for a sustained period in normal temperatures, I'd test my battery.
I neglected to mention that my ESS hasn't been working for a few months and that the associated section of the dash says it's due to the battery charging.

14.0V +/- 0.1V is also at startup.
 

JimThomas

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One of the reasons the ESS may not have been working was low voltage on the main battery. There are many reason why the ESS won’t work, the low voltage is one of them. Removing the fuse and disconnecting the aux battery moves the ESS to the main battery. The new battery with the higher voltage probably was enough for the ESS to start working again.
Question then. What if you pulled the little battery and left the fuse in? Seems like the ESS would turn off at that point, life would be good?
 

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Dgr401

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Question then. What if you pulled the little battery and left the fuse in? Seems like the ESS would turn off at that point, life would be good?
Not sure but my best guess is there would be some kind of error light generated.
 
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wolfdog

wolfdog

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THAW " I assume you mean 14.5/13.5V (not 4.5/3.5)". You are correct shoulda put my cheaters on, typo error gettin' old!

All is well with new battery! Except my ESS after not working for 2 years now functions and now have to push the damn Circle A button!

Thanks ALL for your input, appreciated!!!

Go Jeep!!!
 

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I neglected to mention that my ESS hasn't been working for a few months and that the associated section of the dash says it's due to the battery charging.

14.0V +/- 0.1V is also at startup.
Sounds like at the very least your battery needs a charge, but it might need replacing. Do you have a multimeter or charger?
 
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Ratbert

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Sounds like at the very least your battery needs a charge, but it probably needs replacing. Do you have a multimeter or charger?
I could charge it, but if that fixed it what would it indicate?

When checking voltage, what characteristics should I be looking for?
 

THAW

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I could charge it, but if that fixed it what would it indicate?

When checking voltage, what characteristics should I be looking for?
If charging the battery helped, I suppose it would indicate your driving habits don't charge the battery enough (you probably have some idea if that's even a possibility). I usually maintenance charge my battery once a month to keep it in good condition, since an alternator really has no way to provide a proper AGM charging profile (typical trip length drastically shorter than full charge time).

Check the battery voltage with a multimeter when the system electronics are asleep (i.e. leave the hood open for a while with the vehicle off). Resting battery voltage gives some idea of the state of charge. Rougly speaking, you want to see 12.7/12.8V for an AGM; much less than that and the battery either needs a charge or is degrading so won't benefit much from one. If you can start the vehicle while watching the multimeter, observe how low the voltage goes; a healthy battery should stay well above 10V.
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