I have been charging my 1.5 Roadster (number 189) with an older HPC model 06-001919-00. I've had no problems charging my car. Today I invited another Roadster owner with a 2.5 version car to use my HPC since I have 70 amp cabilities with it, but everytime we try starting a charge on his car it trips the GFI on the side of the HPC and shows red lights on both the car' charge port and the HPC and an error message on the screen in the Roadster saying there is a charger failure. We've tried starting the charging at various other charging rates besides 70 amps with the same issues. Anyone have some insights on this problem. To be clear the HPC still works just fine on my 1.5 version car and Richard has used other HPCs before without issue.