I'll only build a J1772 conversion cable with high quality ITT/Canon parts and assembled with industrial crimping tools by accomplished professionals. I'll test complete empty to full range mode 70A charging before letting anyone else use it. I've done a fair amount of Roadster charging at 30A from J1772 stations and have never had a problem. I use a homemade J1772-to-Roadster adapter that uses a cheap J inlet that Cathy and I soldered ourselves. The right way to do this is with industrial crimping tools, something we didn't have available when we built our prototype adapter in 2010. J1772 Charging for the Tesla Roadster - Tom Saxton's Blog For overnight charging on a road trip, I typically do a standard mode charge to 87% overnight, then kick off a full range mode charge two hours before we're ready to leave. That sets us up to leave with maximum charge. If the timing is right, I'll just do a full range mode in one session. In the first case, there's usually a few hours between when the first charge ends and the second starts. I've done two complete empty-to-full Roadster charges at a Blink station at the Portland Crown Plaza: 42 kWh and 33+8 kWh. Likewise at the AeroVironment station in Wolf Creek, OR: 23+8 kWh. At a ChargePoint station at the Four Points Sheraton in Emeryville, CA we did 15.3 kWh from 120V, then over about 30 hours in three sessions we did 12.7+24.5+9 kWh from the J1772 port. We've done several more sessions around 10 kWh at various Blink and ChargePoint stations. I've never had a problem with the J1772 connector getting hot. Obviously, I don't have a ton of data points since most of our charging has been from either Tesla charging stations or NEMA 14-50 outlets using a mobile connector.