For long term storage, you do
not want to:
- Leave it at a high state of charge (>55% for NCA batteries, >70% for LFP batteries) that can increase battery capacity degradation. In general, degradation during storage is lower at lower state of charge all the way down to 0-1%, but (in lab testing of batteries) tends to get significantly worse above 55%/70% (though degradation is smaller/slower generally with LFP batteries than with NCA batteries).
- Allow it to fall to 0% or lower through vampire drain (which is much greater with sentry mode and/or cabin overheat protection with AC, but can still be a percent every few days with that stuff off).
So an easy safe way to park the car is plugged in with the target charge of 50% (the lowest allowed in the UI) (you can leave sentry mode and/or cabin overheat protection on, at the increased cost of your house electricity bill to keep it charged to 50%). If not plugged in, leave enough charge in it so that vampire drain will not pull it down to 0% or lower (but that requires knowing how much vampire drain there is through previous observation).
However, four days is not that long a time, so you have plenty of leeway with respect to vampire drain.