Jeep keeps draining battery overnight

[AnebuR]

When I pulled out of my garage last Sat night, my radio suddenly rebooted. I figured maybe some update got pushed, although that should've given a prompt first. As I kept driving, the radio kept rebooting about every 5-10 mins. I assumed I just needed a new radio, since by now, we all know how flaky the 8.4 system is. Left the Jeep parked on the street overnight. When I went to start it in the morning, not only would it not turn over, but the display between the gauges was cycling all sorts of warnings like Park Sense not available and sway bar can't be disconnected. Called AAA for a jump. The guy hooked up a portable jumper and the Jeep still wouldn't turn over. I asked him to let it charge for about 5 mins. After that, the Jeep did start and I drove home for about an hour with a rebooting radio, but otherwise normally running Jeep.

Scheduled a service appointment for this morning. Even though the voltage was a constant 14.2 - 14.3 for the duration of the previous night's drive, the battery was at 9.9v this morning and the Jeep wasn't starting, needless to say. Just hooked it up to a charger and waiting to get it going. Will keep you guys posted on what the service department finds. I suspect something might be draining the battery, since it would be unusual for a a relatively new battery to go bad on its own this soon.

Sponsored

 

[Chupacabra]

It's probably the battery... Dead cell or something. Unusual yes, but not unheard of either. Hopefully that's all it is.

 

[AnebuR]

It's probably the battery... Dead cell or something. Unusual yes, but not unheard of either. Hopefully that's all it is.

It might be, but not necessarily the underlying cause. I'd assume that once started, the alternator should be able to provide enough steady voltage for the radio not to keep rebooting, even with a faulty battery. Another fun tidbit I forgot to add is that the GPS shows me randomly about 500 miles away from where I actually am.

 

[Chupacabra]

It might be, but not necessarily the underlying cause. I'd assume that once started, the alternator should be able to provide enough steady voltage for the radio not to keep rebooting, even with a faulty battery. Another fun tidbit I forgot to add is that the GPS shows me randomly about 500 miles away from where I actually am.

Yeah that is odd, when running the battery isn't really relevant. Hopefully they figure it out for you!

 

[AnebuR]

Just got my Jeep back. Apparently, both batteries had bad cells and were replaced. I find that one hell of a coincidence and am wondering whether there definitely is some underlying issue that will just wind up borking both batteries given enough time. They also ordered a new radio, since they couldn't flash my current one, likely cause it keeps rebooting before the update is complete. While I would've insisted they take more time to analyze my Jeep, I don't disagree with their approach, given how close we are to the holidays. I guess try the easy fixes first and hope for the best.

 

[OldGuyNewJeep]

Just got my Jeep back. Apparently, both batteries had bad cells and were replaced. I find that one hell of a coincidence and am wondering whether there definitely is some underlying issue that will just wind up borking both batteries given enough time. They also ordered a new radio, since they couldn't flash my current one, likely cause it keeps rebooting before the update is complete. While I would've insisted they take more time to analyze my Jeep, I don't disagree with their approach, given how close we are to the holidays. I guess try the easy fixes first and hope for the best.

If I were in your shoes, I’d head over to the AUX Battery bypass thread and make that a holiday project. I did it a couple of weeks ago. Easy, and now I have peace of mind.

https://www.jlwranglerforums.com/forum/threads/3-6l-ess-aux-battery-bypass.17293/

 

[AnebuR]

Well, back to the dealership. Just tried to start my Jeep and same thing with two brand new batteries. Voltage was at about 5.3v.

 

[AnebuR]

Their theory is that the radio keeps turning on and rebooting during the night, draining the battery. Rather convenient explanation, given that they already ordered a new radio. I bet they'll likely hold off on doing a thorough investigation on what might be the underlying issue until that's been replaced and the issue persists. Again, I don't blame them for taking the easy route, given how slammed they are at this time of the year. Still, seems rather fishy. Anyone else hear of the radio turning itself on while the Jeep is in the OFF position?

 

[FWB FL]

Just got my Jeep back. Apparently, both batteries had bad cells and were replaced. I find that one hell of a coincidence and am wondering whether there definitely is some underlying issue that will just wind up borking both batteries given enough time. They also ordered a new radio, since they couldn't flash my current one, likely cause it keeps rebooting before the update is complete. While I would've insisted they take more time to analyze my Jeep, I don't disagree with their approach, given how close we are to the holidays. I guess try the easy fixes first and hope for the best.

Same with my Battery's, but 2 new battery's and all is good for over a year now!

 

[AnebuR]

Same with my Battery's, but 2 new battery's and all is good for over a year now!

Did you also have your radio rebooting every five or so minutes?

 

[mwilk012]

Their theory is that the radio keeps turning on and rebooting during the night, draining the battery. Rather convenient explanation, given that they already ordered a new radio. I bet they'll likely hold off on doing a thorough investigation on what might be the underlying issue until that's been replaced and the issue persists. Again, I don't blame them for taking the easy route, given how slammed they are at this time of the year. Still, seems rather fishy. Anyone else hear of the radio turning itself on while the Jeep is in the OFF position?

Yes, bad radios on any vehicle can cause a parasitic draw. Is there a detectable draw on the battery?

 

[AnebuR]

Yes, bad radios on any vehicle can cause a parasitic draw. Is there a detectable draw on the battery?

Didn't get a chance to check. Left it overnight at the dealership.

 

[RoadiJeff]

Their theory is that the radio keeps turning on and rebooting during the night, draining the battery.

That should be easy enough to check. Pull the fuse to the radio and see if the parasitic drain problem stops.

 

[AnebuR]

Just got a call from the dealership that it definitely was the radio, since they pulled the fuse overnight. While they were at it, I asked them to make sure the PCM update (TSB 18-092-19) had been applied when they had my Jeep for the blower TSB earlier in the year. This TSB will ensure a 2018 JL can still start if the Aux battery is depleted.

 

[mwilk012]

Just got a call from the dealership that it definitely was the radio, since they pulled the fuse overnight. While they were at it, I asked them to make sure the PCM update (TSB 18-092-19) had been applied when they had my Jeep for the blower TSB earlier in the year. This TSB will ensure a 2018 JL can still start if the Aux battery is depleted.

Good deal! Sounds like they did a pretty good job taking care of you and your Jeep.

Sponsored