The JDapter has no such warnings.I was motivated to buy the Tesla Gen UMC by this post (rather it''s predecessor) so it seems like a good place to complain. I used it with the Nema 6-20 adapter and a 20ft 12 gauge extension cord. It worked once for an 8hour charge. The next time I tried it, a few months later, it started charging and the gave up after an hour. The UMC no longer lights with any adapter. As it was still under warranty Tesla took it back and promised to send a replacement but they are back ordered because, I suppose, they have to supply one with each Model3 so they have run out for the commoners like me. Others may want to consider my experience with a product that is genius in theory.
After complaining to Tesla, I finally received a replacement today. I plugged it into my 14-50 receptacle and watched the green lights, then plugged in my "teslatap" (labelled "Duosida") and plugged it into my Bolt. Charging worked for about one hour and then was interrupted (no idea why, no blackouts, nothing else was affected). Unplugged everything then tried it all again, it charged for a half-hour then was interrupted. The only commonality in the two interruptions was that the failure occurred near the time when charging was due to end (according to the Bolt dashboard), as if the setup cannot deal with the end of the charging sequence. I tried it a third time (when charging was due to end in ten minutes) and it finished without incident. Anyone have any ideas? Don't blame my 240v line which has been working with my Clippercreek for two years without any problems./forum/images/ChevyBolt/smilies/tango_face_sad.png
I read on the Teslatap website (http://www.umc-j1772.com) the following: "Only compatible with some of the new Tesla Model 3 UMC's and you must use only the NEMA 14-50 or 5-15 connector." That may pretty much kill it for me.