Yup, the BMS needs a good chance to measure the battery across varying states of charge, so that it can measure the battery voltages.
I went from charging every night to purposely running down to < 20% over a few days, and then charging back up in steps each night.
I'm on Octopus Go, and I use about 20 % a day if I'm in the office.
Normal:
80% Start of the day
70% Arrive at work, car sleeps for 8-9 hours
60% Arrive home, car sleeps for 5-6 hours
+40% Octopus Go 00:30 to 04:30
BMS cycle:
100% Start
90% Arrive at work, car sleeps for 8-9 hours
80% Arrive home, car sleeps for 12 hours
70% Arrive at work, car sleeps for 8-9 hours
60% Arrive home, car sleeps for 12 hours
50% Arrive at work, car sleeps for 8-9 hours
40% Arrive home, car sleeps for 12 hours
30% Arrive at work, car sleeps for 8-9 hours
20% Arrive home, car sleeps for 5-6 hours
+40% Octopus Go 00:30 to 04:30
etc.
In practice, it's got down to 15%-16% by the end of the cycle.
It’s interesting to see that you don’t need to take it right down below 10% to cycle the battery.
Is it important to do this in phases over several days or will a good 280 mile round trip journey in one day work to cycle the battery?