Third day with new car, dead 12V battery, second day in a row :(

Six month update: no further issues at 4,810 miles, since March 14 12v warranty replacement.

A dealer replacement of the faulty battery completely fixed my problem.

 

Another benefit to using a battery monitor is to observe how battery chargers actually work. I have a few different chargers, none are the same.

Actually I am a bit surprised you come up with these things. I erased everything else I wrote.

 

Not sure what you meant by that, but what I said was that the 88% SOC shown in your previous post was incorrect because it should be 99% at 12.63 V for an open-circuit and rested flooded-cell. It could be that the monitor was calibrated for an AGM battery or is making some wrong assumptions. I also said that your monitor has no way of knowing whether the battery is being charged or not (because it is not measuring the current). So, I am pretty sure your conclusion that the battery only (or mostly) charges when you put the car in park is incorrect, and what you are seeing is an artifact of the monitor caused by small changes in the DC–DC converter voltage.

 

So, what is the troubleshooting procedure?