I'm also concerned about the 12v functioning of the Bolt. I recently got a little device that plugs into the "cigarette lighter" of the Bolt that constantly reads the functioning of the 12v system from Amazon (Palumma car charger). Very interesting to watch. It reveals a pattern of recharging the battery after a start to 14.9v for a few seconds, then settles down to about 12.6v after a minute. As the battery drops, you see the cars computer charger kicking in at 12.5 to bring the voltage back to 12.6. Any variation from the above pattern will be easily detectable, and will lead me to do a battery load test to check the integrity of the battery. (There is a separate thread on load testing the battery).
When you think about it, all of the cars' computer electronics and sensors are dependent on the good functioning of a lousy lead acid battery. It seems to me that insuring that it is in good shape is key to proper functioning of the Bolt.