panamamike said:
If I run out of battery range, then leave the car off overnight with no charging cable, will I be able to start it up and go the next day?
Don't know how much battery the US version REX will preserve.
The REx generator will automatically turn on trying to preserve the battery pack's charge level at ~6.5%. It would be possible although not easy to park immediately after a very fast run up a steep incline with heat full on such that the charge level could be lower, but likely not lower than ~2% because the car would automatically reduce electric loads to preserve the charge level.
However, no electric load would reduce the battery pack's charge level overnight unless preconditioning were enabled. I'm guessing that preconditioning without an EVSE plugged in would not occur below a certain charge level. If the pack's temperature is considerably lower in the morning than it was when parked, the charge level would drop a bit until the pack warmed up.
The bottom line is that your car should be able to enter drive readiness state the following morning regardless of how you parked it the previous night. The REx engine would start and try to preserve a 6.5% charge level, so you should be able to drive as long as you don't exceed the REx generator's output long enough to discharge to below ~2% where propulsive power would start being decreased.