I have a short commute and have charged to 70% since my '18 M3. When I get down to 30-40% I'll plug in again. During the winter I plug in every night for battery warming.
Charging to 50-55% instead would reduce the calendar aging.
In preparation for a longer trip (at least once a month), I'll charge to 90% and might forego charging until the next day (so unplugged overnight) to keep my battery calibrated.
The battery do not get calibrated.
Balancing = the viltage of the cells equalizes by burning of the voltage of the high cells.
Tesla use top balancing, only at high SOC.
I have had my car for about a month at the time with 55% or lower and the imbalance still only 4mV so the balancing thing is not an issue with low SOC strategy.
Calibration: Not the battery, but the BMS.
The BMS estimation of the battery capacity can drift sometimes.
Showing both low and high SOC to the BMS with the car sleeping makes the estimation of the capacity easier. If the BMS is off, it can ”see” the capacity and adjust the estimaded capacity.
This increases the displayed range but it do not increase the true capacity and not the true range.
If you plan to drive 100-0% then you might gaon a few miles in the navigation, but most often this do not make any difference as for example the Superchargers is more fare apart than this.
If you can, you'll probably want to leave sentry mode off at home to promote good battery health. Battery calibration happens when sentry is off and idle for several hours.
Sentry off mainly makes the battery disconnect, showing the open circuit voltage to the BMS.
In the long term there will be less cycles on the battery with sentry off, but cycles cause a rather small degradation so I would use sentry if I had to due to surroundings.
I’d rather loose 0.1% extra during the cars life than loose the whole car or get it trashed without sentry data.
