Anyone keeping track of the battery's soh

I've been taking a reading every month. This month's was not looking great

Screenshot_20231202-123543 by Darrell Hayes posted Dec 9, 2023 at 2:31 PM

SOC 89.9 - 11.5. I'm guessing this represents the top & bottom buffers. The 11.5 stays pretty consistent, but the 89.9 is the lowest it has been. SOH & capacity just keep dropping, but if you take into account that the buffer keeps growing, the overall capacity seems to stay the same at about 113 to 114Ah.
I've only done DC charging once & tend to keep the charge in the 50-80% range most of the time. I allow it to go to 100% and sit for a couple hours once or twice a month to rebalance. 1.5 years on the road & 9k mi. I'll be interested to see what Mini has to say when I bring it in in June for 2yr maintenance.
I did do a 98mi drive yesterday & had 24% left over, so that is still well over the 114mi range rating

 

I’ve found that my SoH seems to drop during periods where I don’t leave the car plugged in and recovers afterwards, but it takes multiple days of being plugged in. If SoH is based on charge balance, I’m guessing your battery is out of balance enough that leaving it plugged in for a couple hours doesn’t do much.

 

I guess I'll give that a try. I figured since the cell voltage range is only 0.01V, it was probably pretty well balanced, but maybe SOH has nothing to do with voltage range