Keeping balance is good. knowing how much capacity when balance is less important. Running flat just to know the capacity is not something Tesla recommends.
Please read my post more carefully.
The idea is not to run it flat so
you know the capacity... when you hit zero miles it won't go any lower, but you still have capacity. The only way the BMS can know the actual capacity of the pack, is to calibrate it by running the pack flat and then charging to 100%.
Charging to 93% gets the charging circuit to be at constant voltage charging. Upon reaching 93% and when the charging stop, BMS takes voltage measurement of each of the 16 modules and decides which modules need to bleed off some charge (the ones with the higher voltage) by turning on the bleeding resistor of those modules. These resistors are fairly low wattage, so as not to cause overheating and not to highly impact the remaining charge of the whole pack. Balancing remain on for a long time for those module until the next time you charge to 93% to have the CV charging again, at which time the BMS makes another determination on which module's bleeding resistor needs to be turned on.
The theory is that ostensibly at 93% balancing
starts. Some modules may be at full charge then, and some will not. So the BMS starts bleeding down those which are higher, and charging up those which are lower. Eventually all the modules will be close to the same voltage and all will be practically fully-charged. That is full capacity.
And you can see that if balancing were done when the car is
not charging, it would impair range. That would be senseless.
Some have suggested that, instead of using bleed resistors to drain off higher packs (just venting that energy as waste heat), that those higher modules should be diverted to a resistive element in the coolant loop when the weather is cold. I think it's a fantastic idea, but suspect that Tesla hasn't done it because that would drop the module voltage way too quickly, and also the voltage to the element would be quite variable depending on how many modules were diverted to it.
I guess you could do it the same way the service center does it: Open the windows and run the heater on max.
Good idea. Everyone should calibrate their system say, once a year (birthday?) after you're pretty sure you have the pack balanced. (This is where individual module voltage readings would be very handy) You might end up with a few more miles than you thought. Heck if most here have been charging only to 90%, you're surely out of balance, so just fixing that might gain you a few miles.
The car was designed to be charged to 100%. No theorizing is stronger than Tesla's silence on the issue.