As promised, I purchased a 40A OpenEVSE charger kit and I am now providing a brief initial review. It was on sale when I ordered it. The total cost, including free shipping, with a 14-50 plug was $407. I believe this is the least expensive 40A charger available other than the off-brand models from China. I ordered the kit Thursday last week and it arrived by US Postal Service on Tuesday this week.
It took me about 2 hours to assemble the kit. The instructions are not the best as in several cases they rely on photos that are not as clear as necessary (either printed out or on my monitor). Based on this, I found myself double and triple checking wiring which slowed things down quite a bit. In addition, one of the wires in the cable that goes to the car is not used, but the directions do not explicitly mention this. Rather, the other wires are all mentioned, but the unused wire is ignored by the instructions. I took quite a bit of time studying the instructions to ensure that I had not missed directions for this wire.
At first the unit did not work after I finished assembling it. I reviewed the FAQ at openevse.com and it suggested several possible issues, including reversed wires between the control module and the display module. That was the problem in my case. Once I connected the wires correctly, everything worked properly.
I like the web / wifi interface. It provides useful data and allows setting options like charge amperage easily. I also like charging at 40A versus 32A that the Tesla portable charger provides. Using the J1772 adaptor has not been a problem. My Model 3 Performance reported charging at a rate of 29 MPH with the Tesla charger. It now reports charging at a rate of 36 MPH with the OpenEVSE charger. The included charging cable is longer than the Tesla cable which is convenient as the Tesla cable barely reached my charge port. Also, despite carrying more current, the OpenEVSE cable is just a flexible and easy to maneuver as the Tesla cable.
At this point, I am highly satisfied with the OpenEVSE device. At full price and fully assembled, it may not be competitive with the Tesla Wall Charger since they are roughly equal in price, with the wall charger providing 48A. However, in kit form at about $400, I am very happy with the OpenEVSE. If I did not already have a 14-50 socket and associated breaker installed, I might have chosen the wall charger since I imagine installation would have been about the same price as installing the 14-50 socket and breaker. There is one additional benefit of the OpenEVSE charger. It is not proprietary and can charge any EV. Thus, if I purchase a non-Tesla EV in the future, I can still use this charger.
So, other than some frustrating assembly instructions, I give the OpenEVSE charger a full thumbs up.
Please feel free to ask questions as I am happy to share my thoughts and experiences in more detail if requested.