Maybe need Ricky Ricardo to esplain
No, this is the heads up display like your vette. My previous post was all with the motor running, nothing was at rest with the motor OFF.

Prior to start, have no idea, never looked. Last month was checking things and put my meter on the battery and found 12.1V so had the battery replaced. Then was checking the heads up and noticed the 12.6V and wondered if the ALT had an issue. I'm use to seeing around 14V when the car is running all the time, unless there is some kind of heavy load. So I put the heads up on the BAT, stated the car and noted the voltage increase to 14.5V. After a short time it dropped down to 12.6 or 7V (don't remember).

BTW: Hate to tell you this...no I don't..lol.....person I know became very wealthy (to me) a few yrs before normal retirement age. Was average income just before. How did he do it ? Invented an additive to put in soda's (won't tell you which one's bought it) to make it stale / flat tasting after a certain amt of time unopened. Believe it or not.

When I see him I call him fuker...and he just laughs. I like my soda. :)

It's more of a technological world we live in...you don't know what you don't know...until you find out first hand for the most part.

Does your Caddy have an alternator with a clutch ? Many vehicles have these now. That could explain it.

Edit in: Guess not. It's a mechanical one way that decouples during belt quick deceleration.

Don't know, never thought of looking for something like that, its a 2012 SRX (actually the wife's car, mines a diesel pickup).

Most likely computer controlled voltage regulator. Cranks to 14 to recharge after starting, then holds system at 12.7.