Catching up over the past year (Level 2 Charging and a 12V DC/DC converter installed)

 The rear "engine" compartment has gotten a bit more crowded over the past year, I finally got around to programming the MCU to control the Brusa over can bus and can successfully charge the pack, sequencing precharge contactors all from an ESP32 MCU (the code ceased to fit in the Arduino Uno that I started with). At some point, I'll probably move to an STM32F4 micro that supports auto-code generation for some more advanced State of Charge estimation algorithms.

I also learned what happens if you apply a reverse polarity to a Chevy volt DC/DC converter module. As you might suspect it lets the magic smoke out, it was actually quite spectacular and loud. So for the 2nd try, I opened up the unit and confirmed which was the proper positive terminal, along with adding additional lower current fuses in the HVDC wiring. Details on the converter can be found here
media3.ev-tv.me/VoltAPMUserGuide.pdf
fortunately many units are available on eBay.