Dr. Prius battery life test?

I have a 2017 with 81 000 miles (niMH). I tried the battery life test and I did what the app asked. Put the car in Drive, pushed the gas pedal and the brake. Then, I ran the AC with headlights on to make sure it drew enough current. It took around 15 minutes to discharge the battery. In the end, it gave me a result of 63% capacity. I was surprised since I was expecting to get another 8 years out of this car before it needs a replacement. I know hot climate kill battery but I'm living up north where it remain below freezing for six months. Is the test really that accurate or it need to be done a few times to account for variables?

 

I did it again but, with a warmed up battery and engine after a 40 miles trip. You have to charge it to 80% but, this time, the charging stopped when it reached 70% (9 bars out of 10). Nonetheless, I did the whole process making sure it always drew between 5.7 and 6.5 amps until it reached 40%. In the end, it gave me 67% capacity. It looks like there are too many variables... Is there any way a dealer could get more accurate results? I read, on Toyota.com that the HV battery warranty apply when you have less than 70% capacity left. I don't have any trouble codes and there is less than 0.2 volts variation between each blocks. It's just that it would be great if I could avoid a costly repair after the warranty is over.