It’s not theft unless the owner specified in the conditions of the rental that car’s couldn’t be charged at the property. (Even then “Theft” is a strong word!)

That being said - there is obviously a big difference in charging your phone and charging a car and really we are at a point where this should be clear in all holiday rental agreements one way or another.

I don’t think the owner would be happy if someone just turned on all the taps in the house and left them running for the entirety of their stay. There is a sort of “fair use” which is assumed (if not actually in writing)

Question comes if car charging should always be assumed “fair use” or is that above and beyond? Or is it a gray area that just “depends”… Much better for everyone if all this is made as clear as possible in the agreement right at the beginning.