It's confusing when people say things like "if you have stop start you have 2 batteries". Technically true, but it's either 2x12v batteries without etorque or a 48v battery and a 12V battery with etorque.
It's a common misconception that Aux is a "Start/Stop Battery" since it showed up when Start/Stop did. But it's not. Aux is an electronics and communications battery that is isolated during engine starts to provide clean stable power to the electronics and communications network.
Kind of semantics at that point, it's not the starting battery, but the one that provides power during all those start/stop events. It wasn't necessary when your vehicle started once per trip.
It wasn't necessary on the JK which has MUCH less reliance on the electronics. The JL is the most drive-by-wire vehicle Jeep has produced. Combine that with the Wrangler being the most owner customized vehicle there is and it becomes apparent why they took an extra step to insure cleanly powered electronics.
The aux battery is a Stop/Start and only a Stop/Start battery from all the evidence I see, what is your evidence to the contrary?
All etorque setups are the same. 48v primary battery under the drivers side opposite the fuel tank. Belt start generator that charges at 48v. The 12v battery is charged by the 48v battery. Using a battery tender on the 12v is still a good practice as it's standard lead/acid configuration with discharge over time. The 48v battery is a lithium ion pack and will hold a charge for a very long time so there's no need to worry about it. The 4xe is an entirely different set up that has a massive battery under the rear seat, charges vis plug in and/or regenerative braking, and I believe operates around 400v.Appreciate the knowledge and input assistance here.. Won't lie, I've heard this so many different ways in regards to the "Primary" 12v Battery and the "Secondary / AUX" Mini 12v Battery that is supposedly under the Passenger Firewall area in the Engine compartment.
Last I'd heard was that only the 4xe and the 2.0L 4 cylinder had the 48v battery and that the 3.6L V6 eTorque had the Primary 12v and AUX 12v Battery.
I have a 2023 JL Rubicon with the 3.6L eTorque. So which Battery combination do we have with this Engine?
On a side note, I use a 12v Battery charger / tender as I don't drive it much, I'm guessing that this would only charge the main 12v Battery then and not the 48v Battery.
-Thanks..
The JL Starting - Charging System wiring diagram. Aux is only powering the electronics, communication and relay controls.
But claiming it has nothing to do with the addition of stop/start is burying your head in the sand. When you're vehicles starting battery is going to start the vehicle 50 times a day, the odds of its voltage dipping enough that the sensitive electronics may have issues goes way up. That is why they added the dedicated battery to run those electronics independent of the constantly under heavy load in town starting battery. The electronics have always been sensitive. Killed a pcm in my 89 xj from low voltage caused by repeated long winch pulls. Are the new electronics more sensitive to voltage drop? I'm guessing no as our 2019 etorque had the 4LO 12v charging issue many have had, dropping as low as 9v a few times to the point it had to sit for hours before the 48v battery put enough juice back in to start and run with no ill effect on the electronics for 40k+ miles after that. The fact is the aux battery was added because of the ESS period.
I don't see it that way because engine starts aren't particularly hard on AGM/Lead-Acid batteries. It's always a large sudden discharge followed by an immediate recharge. That's the AGM/Lead-Acid wheelhouse, it's the best kind of battery for those functions.
The aux battery is lead acid though? My 2017 ram had all those features you mentioned, no ESS, and no aux battery? It literally had the exact same 8.4" uconnect? See it how you like, but ess was really the only change and along with it came the aux battery. Anyone who's ever had a flooded carb will disagree with your immediate recharge theory of lead acid. Too many starting/cranking events in quick succession has always lead to a low battery and always will. Traffic light after traffic light where the engine runs less time than its off or even starting is no different than a vehicle that won't start or won't idle. It's draining on the main battery.
Yes, Aux is AGM Lead Acid.
