Well I have my 100 dollar ESEV, it has a solid ground fault indicator ( which I knew before purchase ) and have started the process of taking it a part.
My initial goal is to fix or disable the GFI feature and to then modify the board for 240V operation
I've spent a few hours tracing things out, looking at part numbers and have a good feel for how this is designed ( I am EE with 30+ years design background )
So here is my first impressions and comments
1) The unit is pretty easy to open up. Just use a flat blade screw driver and pry the top cover off. It is welded, but doesn't take much force ( on this unit anyways ) to break the weld. To put back together would just need some silicon to hold to cover back on
2) Removing the PCB is a major pain-in-the-ass. One has to cut some wires, remove some screws, but one screw is un-accessible as its under the bump where the J1772 cord enters. I ended up drilling a small hole to get a screw driver to remove the hidden screw
3) Once I had the PCB out and flip over, my jaw dropped with all the components. I have reviewed the open source design and it has about 1/20th the part count. These units have a relay for all 5 J1772 wire, a low-side current measurement, which is one of the reasons you can't just make the neutral the other phase for 240V, GFI, dual power supply's, a pair of atmel processors and associated parts
Summary, this is a single phase design and cannot have split phase 240 ( US ). It is though worth nothing but a firmware change should able to handle 230 vac as that's what is used in the EU ( still one neutral one hot ). the internal supply's are rated for the higher voltage.
I've heard from other forum member's that most of the units sold, all have the ground fault issues, in varying degrees, as i first guessed these are earlier prototypes
For 100 bucks, its worth the parts if you want to build your own charger and as time allows, I'll do my best to fix the GFI and then come up with a method for 240V operation, for now, its a time filler / fun time project