Tesla Model S Supercharging Rate

Update Jan 23, 2020: I charged my S100D at a different supercharger (Colorado Springs) over the weekend twice. It was cold with temp in 34-38°F range and I arrived at the supercharger after having driven 100+ miles with 30+% SoC. Both times I saw 8-11 kW more than the above graph at the same SoC. By this time my S100D had been updated to firmware 2019.40.2.1

Update Feb 2, 2020: After I got 2020.4.1 update for 2014 S85, I supercharged at the same supercharger again. I had driven about 75 miles and temperature outside was 70°F. I charged from 20% to 56%. This time I saw 89 kW at 20% SoC. From there on,  I saw 7-19 kW more now than I saw with 2019.32.12.7. At 55%, I was still seeing 57 kW compared to 49 kW previously. Charging rates may have been improved for older batteries with recent firmware updates. One of these days I will update the following charts when I have more time. 

Since the firmware version v10, there have been several reports of supercharging rates having been dropped significantly on older Model S. Since I own a 2014 Model S 85 (built May 2014) and a 2017 Model S 100D (built June 2017), I charged them both at the same supercharger using the same stall and recorded charging power at regular intervals. I tried to keep conditions as close to to same as possible. I first charged the 2014 S 85 one day under following conditions:

Model Year: 2014
Battery Size: 85 kWh
Starting SoC: 10%
Ambient temperature: 72F
Firmware: 2019.32.12.7

I then charged 2017 S 100D couple of days later under following conditions:

Model year: 2017
Battery Size: 100 kWh
Starting Soc: 10%
Ambient temperature: 63F
Firmware: 2019.32.12.7

Since temperature the second time was little lower for 100D, I drove an extra 30 minutes before plugging into supercharger to make sure initial battery temperature would be close to the 85.

Here is the plot showing charging power at various battery percentages (click here for interactive chart).