Oddity with 12V battery voltage measurements andtranmission

Finally managed to get some current measurements with the car in the high and low voltage states. Voltage measurements on the battery, current measurements with a clamp ammeter on the positive cable that runs to the front of the car:

Transmission in "D":
13.6V with current varying mostly between 30mA and 70mA (sometimes a little higher) into the battery.

Transmission in "P":
14.1V, on the transition from 13.6V the current went briefly over 2 A (too fast to read more than the first digit) then it fell back in seconds to somewhat over 1A, but varying. Again, into the battery. Let's call it 1.2A with huge error bars.

The current at 13.6V is very similar to what I have measured for a BatteryMinder 1500 on the same car, once it is in float mode. The current at 14.1V is at the high end seen during the absorption phase with that charger. I did not wait long enough to see if it continued to behave like the absorption phase. If it did it would have fallen very slowly (over hours) down to 200-300 mA.

Turned the car off, opened and closed a few doors and then locked the car, then waited 5 minutes, and the battery was reading 12.65V. Before the drive the car had just come off the charger and it was also at 12.65V. Seems to me that this Prius is somewhat overcharging the 12V battery for no obvious reason. The battery is fully charged as far as a battery charger is concerned, but the car often pushes it to a charging voltage anyway. Admittedly that is only ~1/40C at worst, and probably ~1/150C (300 mA) at best. Still, float is ~1/600C and down.

One other odd observation (so many...). Drove the car or had it sit in READY for about 35 minutes. That entire time it was stuck at 14.1V. Stopped at a store for 10 minutes where the car was turned off. After turning it back on in a few seconds it was showing 13.6V in "D" again, and it stayed like that for the 20 minutes it took to get home, and 10 minutes more while I made those measurements. Almost like the logic got stuck on the first part of the trip somehow, or power cycling is needed to let it reexamine the state of the 12V.