Btw, you do have a 12V system voltage display as an option in the area between the gauges. For those who weren't aware, here's how you activate it:
1) On the right spoke of the steering wheel, press the left arrow to activate the main menu.
2) Use the down arrow to scroll down to "Options". Press the "check" button in the middle of the up/down/left/right arrows.
3) Use the up or down arrow to get to "i" with a circle around it.
4) Use the right arrow to get to "Edit List". Press the "check" button.
5) Arrow down to "Battery Voltage" and press the "check" button.
6) Keep pressing the left arrow until until you're back to the main menu.
7) Arrow up to "Info", then press the "check" button.
Now there will be a system voltage display added to whatever other items you've selected for your normal scrolling menu between the gauges. My '17 MH is in the low 70ks for mileage now with mostly highway miles, so I've spent a fair amount of time watching the system voltage. Except for the one time the car died on me, when the battery dropped to 11.8V, it has always run between 12.5V and 15.5V...oddly, more often at those extremes than you would expect. The car often sits for a week or two between uses, and always with a CTek smart charger connected under the hood. Consequently, the 12V battery always has a full charge on it when I start any drive...and yet the voltage monitor will often show 12.5 as I start a drive. This has been true since the car was new, so I quit worrying about it. And as for the 15.5V readings that I see occasionally, I used to worry about that as well...until I did some reading on the charging requirements of AGM batteries. They appear to favor a sightly higher charging voltage...at least 0.5V higher than a conventional battery, if not more. I suppose I'll be needing a new battery at some point, but have not noticed any performance degradation so far (knock on wood).
I hope all this is useful to someone.