Yes, please define usable. Tesla sometimes shows battery capacity locked out due to cold, etc but I don't think that's what you're referencing here...
Is this "Useable" calculation based on Temperature, efficiency, degradation?
Can you explain how 'usable battery level' is sourced. I've checked twice today and it matches my energy chart+ consumption+30 miles+average (vs instant) .. "Projected Range" exactly. Maybe popup/hover help box over it?
Customer support service by UserEcho