Assessing overall HV battery health

Greetings everyone,

I have a 2005 Prius with 70k miles (purchased from private party last December with 66k miles). I reside in Sonoma County, CA, where the weather is relatively temperate (see attached chart of average highs and lows throughout the year).



Although the likelihood of having an HV battery failure at this point is low, I’d like to assess the battery’s overall state of health. If nothing else, this I’d like to establish a baseline to measure against in case I have problems in the future.

Based on a 45 mile trip a couple of days ago, I compiled some data regarding the voltages of the individual battery blocks. With 3,384 rows of data, here’s what I came up with…

# of instances each individual battery block reported the lowest/highest voltage:



Difference between highest and lowest battery blocks:
Mean: 0.178716612 volts
Median: 0.17 volts (kept it to 2 decimal places in order to get a meaningful figure)

Clearly, block 0 had the highest voltage most of the time, with block 13 coming in a distant second.
Block 10 most commonly had the lowest voltage, followed by blocks 11 and 8.

Questions:
Do with these numbers, do I have any reason to be concerned?
At what voltage difference between blocks should I become concerned?
What other data should I collect/compile in order to assess the health of my HV battery?

Any feedback/suggestions would be greatly appreciated.

Thanks!