Combining 120V supplies for 240V

There is a way to double your charge rate when you have 120V supplies (either through TT-30s or regular household 120V plugs) but I really don't recommend pursuing this. I tried it once in a rented condo with a box I built (using safety relays) and it just didn't work, even though it had worked at my house.

Instead, I'd recommend getting a portable EVSE that allows you to charge at 16A from a 20A receptacle (instead of the regular 12A) since a lot of newer condos and houses have 20A receptacles in their garages. Also, you can sometimes get access to a 30A dryer receptacle. Go to this page to read about portable EVSEs.