OMINOUS BATTERY WARNING

[sixspeed]

For the last few days when I start up my 2020 JLUR, I get this message on the screen:

Aux Switches Temporarily Unavailable Battery Charging

I assume that this, ultimately, means that one or both of the batteries are going bad?

Anyone enlightened on this issue?

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[Terrymo]

For the last few days when I start up my 2020 JLUR, I get this message on the screen:

Aux Switches Temporarily Unavailable Battery Charging

I assume that this, ultimately, means that one or both of the batteries are going bad?

Anyone enlightened on this issue?

Nothing ominous is happening and there are lots of threads related to this in the battery talk forum if you’re curious. If you’re not driving frequently enough for long enough to keep your battery topped off above the voltage threshold prior to starting, that would explain the message. Or if you have something causing an unusual parasitic drain that could explain it.

If you’re driving frequently for long enough and your batteries have aged out, then yeah your assumption is correct.

 

[GabeBoyTheGreat]

Yes, one or both batteries are going bad (with the caveats mentioned by @Terrymo). When I had that message, it was my main battery.

You could have the batteries load tested to be sure, but you need to isolate them. Disconnect the main battery completely before testing; that should isolate each battery. If you don't isolate them, you will likely get a false pass because both batteries are contributing to the test.

Even if you isolate them, in my experience, the Jeep electrical system is more conservative when it comes to failing batteries. Meaning, it might fail according to the Jeep but pass the load test. I have had this happen before. The test came back as "passed" but not fully charged; however, I knew the battery was still bad because there was no reason for the battery NOT to be fully charged. I ended up replacing the main battery, and the message went away.

My recommendation is disconnect the AUX negative cable from the main battery and isolate it, and then remove fuse F42. If the message goes away, then it was likely just the AUX battery. You could just leave it disconnected and go about your day. Alternatively, you could replace and reconnect the batteries.

 

[Raydar]

I have been seeing that message occasionally for several months.
My JLU is a '21, 3.6 manual, and still running the original battery. The AUX battery has been disconnected, and the ESS disabled. (Actually worked!)
I have had the message pop up once, even after the engine had been running for a while. Probably was when I almost - but not completely - stalled the engine, being sloppy with the clutch.
It still starts just fine, and has been since this started happening. The battery voltage always shows 13.xx-14.xx volts.
I'll mention that my blind spot monitor will occasionally get "stuck", alerting on both sides, but a quick restart clears that. I don't think they're related, though. The blind spot thing started way sooner.

 

[Kracka]

2020 means your battery(ies) are 6-7 years old... You're due regardless of warning signs or not.

 

[Heimkehr]

...and if you want both the Main and the Aux battery in active service on the vehicle, both should be replaced at the same time.

 

[PT's19Rubi]

In addition to normal parasitic draw, I have a dash cam with parking mode (leaves camera on, in low frames/second mode) until a set voltage is reached and then shuts off. One or two days sitting are okay. One or more weeks sitting and I likely get the message you get. So, initial draw down by the dash cam leaves enough battery, but normal draw down will eventually pull battery down below message threshold. I have tried to get in the habit of turning the dash cam off when parking at home (off street, in carport). This gives me more than two weeks before message. Long story short - are you running a dash cam with parking mode?

PS. I recently replaced my 2019 JLR main battery, and disconnected Aux battery long ago. The above was after battery replacement. After around two weeks parked, and with camera off, I try to charge the battery for just-in-case sake.

 

[Raydar]

Long story short - are you running a dash cam with parking mode?
...

I'm not running anything other than stock equipment. I occasionally charge my flashlight through the USB, but not on a regular basis.
No dashcam or other "keep-alive" circuits.

 

[PT's19Rubi]

I'm not running anything other than stock equipment. I occasionally charge my flashlight through the USB, but not on a regular basis.
No dashcam or other "keep-alive" circuits.

If you're getting less than two weeks, you are either getting excessive parasitic loss or have bad battery(s). Excessive loss can be a real **itch to find, much less fix after finding, I would look at battery(s) first.

Note: Just noticed you're not the OP. At 5 years on original battery, I'd replace battery. Actually that's about how long mine lasted. And yes, a battery on its way out can cause some really odd stuff on modern computer controlled vehicles.

 

[Raydar]

If you're getting less than two weeks, you are either getting excessive parasitic loss or have bad battery(s). Excessive loss can be a real **itch to find, much less fix after finding, I would look at battery(s) first.

Note: Just noticed you're not the OP. At 5 years on original battery, I'd replace battery. Actually that's about how long mine lasted. And yes, a battery on its way out can cause some really odd stuff on modern computer controlled vehicles.

Yeah... no. I'm not having any issues other than the message and the ghost blind spot arrows.
I never have been stranded with it, and I keep a jump pack in the storage compartment.

But I suppose I ought to just replace the battery. Except the one in my JK is worse. It becomes a doorstop if it sits for a few weeks. I know it needs replaced.
The JL is my driver, so it only sits a day or two at most. And stop/start has been disabled.

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