What is your voltage at?

[McGilli]

When I bought my Jeep - it would be in the mid-high 13's all the time when running.

Ever since installing 2x6000mah batteries under the driver seat (for powering my dash cam when the Jeep is off) - that are charged while the Jeep is running it's always at 14.2 - 14.4 - unless ESS turns on then it goes into ~13s until I get moving again.

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[Slowpoke]

ESS suddenly not working.
No warnings or codes or dummy lights displaying.
ESS button not lit. Will light if button pushed
Jeep starts fine, everything works as normal.
Have had zero issues with this JL.
29° and warmer
2018 Pentastar JL, automatic
25,000 miles, daily driver
14.6v at idol. Have not monitored while driving.
I don't care for ESS, but I know it should be working.
Any ideas?

 

[Gee-pah]

ESS suddenly not working.
No warnings or codes or dummy lights displaying.
ESS button not lit. Will light if button pushed
Jeep starts fine, everything works as normal.
Have had zero issues with this JL.
29° and warmer
2018 Pentastar JL, automatic
25,000 miles, daily driver
14.6v at idol. Have not monitored while driving.
I don't care for ESS, but I know it should be working.
Any ideas?

On a 3.6L at least:


Trickle charge if possible at rest. Put charger's prongs on main battery. The charge will get to both batteries as the two batteries are connected in parallel when the vehicle is at rest.

Let us know if this addresses things.

Other things:

disconnect cable on main battery's negative post CLOSER to front passenger's quarter panel. Put volt tester on main battery's terminals and note that voltage--which is the main battery's voltage.

Now move the negative prong of your tester to the dangling cable, keeping your positive prong on the main battery. Note that voltage--which is the ESS/Aux battery's voltage.

Reattach that cable.

Consider load testing each battery individually using the above cable isolation technique. See what your results are.

Take it to the dealer where I'm not sure you'll get an honest answer..

 

[Slowpoke]

Gee-pah, thanks for your suggestions. I will try these this week as time permits. I will let you know my findings.
The dealership is the last place that I want to take our Jeep. I always ask these forum members for their experienced help first. Thanks again.

 

[DavidArmen]

Mine goes from 13.5 to 14.2 when the engine is running. If it’s not, it goes as low as 12.x
2021 3.6 eTorque

Update, January 29, 2022:

After over a year of ownership, I have noticed that because of the intelligent charging system, the computer will disengage (or even vary the power output of) the alternator/generator, even when the engine is running, whenever the battery is fully charged.

However, the alternator/generator will still engage if there is a large load activated, such as heated seats, even when the battery is fully charged.

This ‘smart charging’ is to lengthen the life of the battery by not constantly pumping 14.1v-14.5v into it even when it’s fully charged, and also helps slightly with fuel economy and performance by disengaging the alternator when the battery is fully charged, so the engine no longer needs to power the alternator/generator, which uses a small percentage of available engine power whenever it’s engaged and charging the battery.

If I start the engine after not driving for a couple of days, the voltage goes up and stays around 14v for about 30-60min but then the voltage starts to slowly decrease to the 13s the more I drive, as the battery gets more and more charged up.

It is not uncommon to see a voltage reading in the high 12s even with the engine running, when you are towards the end of a multiple-hour drive, which gave the charging system enough time to fully charge the battery. The system then keeps the battery topped off without overcharging it by lowering the voltage to the 12s.

Also, instead of a traditional alternator, my Jeep has a motor/generator which charges a large 48v lithium-ion battery which then in turn charges my conventional lead-acid 12v battery, so I can’t be 100% sure that Jeeps with alternators and auxiliary lead-acid batteries behave in this same way, especially in regards to the variable-rate charging capabilities.

 

[WranglerMan]

@DavidArmen my 2018 performs as you described, I don’t have a stock battery setup and recently took the IBS out of service and the smart charging aspect still performs the same.

If it’s parked for several days it displays 14+ and as I drive and the batteries become more charged it slowly drops but when my air comp is used or I run my winch I see the voltage output jump up and as you said this is by design.

 

[DavidArmen]

@DavidArmen my 2018 performs as you described, I don’t have a stock battery setup and recently took the IBS out of service and the smart charging aspect still performs the same.

If it’s parked for several days it displays 14+ and as I drive and the batteries become more charged it slowly drops but when my air comp is used or I run my winch I see the voltage output jump up and as you said this is by design.

Very interesting to know the IBS isn’t required for the variable ‘smart’ charging system.

 

[WranglerMan]

Very interesting to know the IBS isn’t required for the variable ‘smart’ charging system.

If you can muster thru me be long winded and make it thru my OCD you may find some of this info useful.

https://www.jlwranglerforums.com/forum/threads/my-testing-of-the-ibs-ibm-system.79412/#post-1658671

I tend to go on and on but you may be able to get at least some info from my dribble as it seems once I find something that catches my interest I hang on to it and beat it like a cheap rug.

I was running into random issues with battery protect messages and so far disabling the IBS thru JSCAN has corrected this but did not affect smart charging but as Jerry pointed out it won’t as it only enhances the already overly designed system.

 

[Vaunswa]

So I just traded my ‘19 2.0 with etorque for a 19 v6.
2.0 always showed around 14.4 voltage,now the v6 is always around 12.9.I have a few months warranty left on this Jeep and want to make sure the charging system is normal.
Any concerns?

 

[ErAcEr]

So I just traded my ‘19 2.0 with etorque for a 19 v6.
2.0 always showed around 14.4 voltage,now the v6 is always around 12.9.I have a few months warranty left on this Jeep and want to make sure the charging system is normal.
Any concerns?

I would be concerned. Mines almost always been at 14v. There is another thread about what terminals to disconnect to check the voltage of each battery and to see if the fail safe TSB/Recall was applied so that it would start with a bad EES battery.

 

[Shooting or Jeeping]

Update, January 29, 2022:

After over a year of ownership, I have noticed that because of the intelligent charging system, the computer will disengage (or even vary the power output of) the alternator/generator, even when the engine is running, whenever the battery is fully charged.

However, the alternator/generator will still engage if there is a large load activated, such as heated seats, even when the battery is fully charged.

This ‘smart charging’ is to lengthen the life of the battery by not constantly pumping 14.1v-14.5v into it even when it’s fully charged, and also helps slightly with fuel economy and performance by disengaging the alternator when the battery is fully charged, so the engine no longer needs to power the alternator/generator, which uses a small percentage of available engine power whenever it’s engaged and charging the battery.

If I start the engine after not driving for a couple of days, the voltage goes up and stays around 14v for about 30-60min but then the voltage starts to slowly decrease to the 13s the more I drive, as the battery gets more and more charged up.

It is not uncommon to see a voltage reading in the high 12s even with the engine running, when you are towards the end of a multiple-hour drive, which gave the charging system enough time to fully charge the battery. The system then keeps the battery topped off without overcharging it by lowering the voltage to the 12s.

Also, instead of a traditional alternator, my Jeep has a motor/generator which charges a large 48v lithium-ion battery which then in turn charges my conventional lead-acid 12v battery, so I can’t be 100% sure that Jeeps with alternators and auxiliary lead-acid batteries behave in this same way, especially in regards to the variable-rate charging capabilities.

And just because I ran into this in real time- I can attest to this. My voltage was running in the 13.9-14.2 range for a while and then I got the message that ESS was disabled for battery charging. After about 2 months of this, I decided to take it in to check. The Aux battery was dead, but the main battery was fine. Because of part shortages, the Aux is on a 6 week order.
Frustrated, I left and decided to watch it. Still the same voltage, but after about 2 weeks, the error changed to “Aux switches disabled” and that lasted a few minutes while it ran. The voltage then went to 14.3 for about a week (pretty much steady) and then the main battery gave up.

Thankfully, I was able to replace both within a day of each other (btw- battery is covered under 3 year warranty),and now the voltage runs at 12.7 most of the time. You’ll see a spike or two to 13.7, but then it drops. This is supposedly the battery monitoring kicking in as needed.

So if you see 14.+ on a regular basis, it’s safe to say 1 or both batteries are on their way out.

 

[Old Dogger]

Mine averages, around 14.2.

 

[smokeythecat]

I didn't pay attention at first, but my ESS stopped working and voltage was a constant 14.7V. Dealer charged battery and said problem fixed, voltage down to 14.2V and ESS working. Slowly started creeping back up, 14.5V , and ESS stopped working. Back to dealer had it again for an entire day, just charged the battery. (I always get the ESS not avail, battery charging) From what I understand, this problem is due to lots of short trips, and a possible bad battery.

So, if you charge an overcharged battery it will drain the battery? You went to the dealer to have them drain your battery a little bit?

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