2019 M3 LR, Battery degradation

[vasuvius]

My M3 LR is 3 years old and has 30k miles on it. Recently I noticed that 100% of battery capacity is 274 miles instead of the 310 it should be. Tesla Service says that we should expect a 4% degradation per year which explains the current capacity numbers. (There’s no clarity on whether it’s 4% of the original capacity each year or whether it’s an exponential decay)

I’m trying to figure out the best charging pattern for battery health and there’s far too much conflicting information.
80% of our charging is at home 50A/240V wall outlet and the rest is superchargers.

Initially we followed the instructions from Tesla and plugged in the charger every night set to 90%. And then about a year or so ago, the charging system started giving us warning messages that repeatedly charging the battery when the usage is low is bad for the battery. Since then we’ve been charging to 80% except when we need to travel further.

Having read through a whole bunch of threads on this the answers are not very clear

 

[GtiMart]

IF you do the steps that are described in the thread How I Recovered Half of my Battery's Lost Capacity , you might get a better estimate of your capacity. It's possible that it's not all "lost" but that the BMS isn't quite calibrated properly. For the rest, it's normal to have lost a few percent.
Looking at TeslaFi, my maximum range estimated at 100% has oscillated between a bit under and a bit over the average of the fleet, depending on whether I've stayed at a stable SOC or if I did a road trip where I went down low, up high etc, a bit like what that thread talks about. Don't worry.

 

[vasuvius]

It’s going to be a bit tricky to try that charging pattern. The car is my wife’s daily driver and range anxiety kicks in at about 50%
But I can try to get capacity down to 30% before plugging it in.

 

[AlanSubie4Life]

Having read through a whole bunch of threads on this the answers are not very clear

If it works for you, plug in every day and set the limit to 50%. If 60% works better, use that. A bit late for this three years in but you might slow calendar aging a little.

Save the calibration for a road trip or something. I’ve never seen that do anything at all on my car though.