Slightly peculiar 12V battery observations

The 12V in our 2007 was charged to full with a Battery Tender Jr. yesterday. Measured at the jump point before charging it was 12.54V (at around 70F). That is around 75% SOC on most AGM tables. This particular charger maxes out at .750A, and in this case after starting it rapidly climbed to .578 A at 13.48 V and then over the next 3.75 hours the current fell to .549 A while the voltage rose to 13.67. This was 2:00 PM and it was starting to get really hot out, so paused until the car was in the shade of the house, restarted at 5:15 PM (12.73V measured right before) and by 6:15 PM it was flashing green (13.57V, .53-.56A oscillating), and at 6:50 PM it was solid green (float) at 13.13V and the current varying rapidly between 0 and 0.6A. I have no idea what the shape of that waveform is.

Anyway, let it sit overnight and it was 12.69V at 8:15 AM (70F), but down to 12.57 V at 14:24 (at the jump point), it is a hot day and it was at least 85F by that point. It was not driven today. Then a battery test (HF electronic battery tester) was run on the battery in the car. SOH 85%, SOC 100% AH 43 Volt 12.66 Internal R. 8.56 mOhm. Typical for this battery recently.

So the peculiarities...

1. Using an IR "gun" thermometer measured the temperature in the car through the 1" gap at the top of a window as 115F. However, the temperature of the battery (gun aimed right at it at close range) was only 105F. The battery was on the north side of the car, so the sheet metal right next to it was not in direct sun. Anyway, there can apparently be quite a substantial difference between the 12V temperature and the cabin temperature for a Prius parked in direct sunlight, with all 4 windows rolled down one inch. Intrinsically - there were no fans going.

2. Measured voltage and current at battery with UT210E multimeter and found 12.65 V (same as the tester) but only 13 mA. I have only ever seen 25 mA (car inactive for a while) or more (door open or car active). Current test was repeated 2 more times with the same results.

The second of these is more interesting. Some possibilities are:

A. Heat affects car and/or battery so less current drawn. Never measured on this hot a day before. Boring.

B. Heat affects multimeter Again, never measured on this hot a day. Boring.

C. Recently started turning off the cabin fan before turning the car off. The car somehow knows this even when off and uses less current. Not Boring.

A and/or B are more likely, but C would be interesting if true. I started turning off the fan because of the observation that under normal operating conditions (car fully warmed up, in D or P) the inverter puts out 14.1V or 13.6V, depending solely on whether or not the cabin fan is going. This is a binary decision, it is 14.1V for any fan speed even though the current used varies tremendously. I figured that if the cabin fan is initially off it should lower the startup current from the 12V battery, in whatever period the cabin fan was working off the 12V battery before the inverter took over, which would be better for it long term. I didn't expect that the fan position would matter while the car was off though. Probably it doesn't, but it would be fascinating if that actually makes a difference.