New Theory re 12v/Sulfur Smell and anomalous ICE running
Humor me please. I've just gotten my 2017 pachy back from the shop for the third time in a 2 month period. Very strange experience. Problem started with the sulfur smell when charging with the level 1 charger. Around the same time I was also noticing strangely loud ICE engagement when main battery still had plenty of life on it. At the time, I chalked the erratic ICE behavior up to colder weather (mid 30's to 40F), and thought it was separate from the 'boiling 12v battery when charging problem'. First dealer performed some needed software updates but was unbelievably ill equipped to service the hybrid (if you can believe it, they didn't have a functioning charger there). Problem recurred immediately -- dangerously high levels of hydrogen sulfide in my attached garage when charging. Stopped charging the van at home and booked an appointment with the other local dealership. In the meantime I went to Autozone and got the 12v battery checked there. Voltage was ok, but CCA reading is low. No clear indication of a shot cell, but a weakened battery. Here's where it gets weird: When the second dealership charged the van on their level 2 charger, I was told that they had no problem. I then brought in my level 1 charger. Sulfur smell and battery hot to the touch after 50-70% charge is reached. They profess to be mystified and 'open a case' with Chrysler tech support. It all culminates, as anyone here would have predicted (and as I explicitly suggested from the get go) with a new 12v battery being installed. This leaves me with 2 questions: why would the problem happen on level 1 and not on level 2 charging? Has anyone else had a similar experience? (I find this so baffling that I suspect the dealer didn't actually check this carefully). But secondly, mustn't their be a problem in how the condition of the 12v battery is monitored by the vehicle, such that it is 'trying' to charge the 12v when not needed? (On another thread someone even spoke as if it were a known thing that the Pachy doesn't have an adequate 12v battery monitoring system in place.).
Here's my new theory -- sorry for the agonizingly long build up: could the strange/apparently unnecessary ICE engagement also be related to the vehicle 'thinking' that the 12v needs charging? Is the 12v charged from an alternator off the ICE? Or does all charging of the 12v go through the main battery pack? I ask because today, with a new 12v, the van runs amazingly smoothly, with no ICE activation at all -- though it is 39-40F.