Posted by ChadS:
Yup, your Leaf's J1772 EVSE will work fine with the Model S. There's just the hassle of moving it between the Leaf and S.
It will probably charge at 30A, although it's possible it was installed at a lower level (the Leaf only pulls 15A). 30A should still generally be over 20 miles or range replaced per hour of charging, so overnight should be fine unless you plan to completely drain the car two days in a row.
For more info on charging a new Model S, see THIS thread.
I don't think you're in an EV Project area, so I'm not sure what EVSE you have. But if it's a Blink,
HERE is something to consider.