Thought I'd post with a report of my first experience of the HV battery shut-off in our ZS Trophy Long Range. We were charging using a Gridserve rapid at Stone services northbound on the M6. As I'm used to my MG4 now I no longer instinctively press the on/off button when you stop to exit the car. I then proceeded to try and rapid charge whilst the car was still 'on'. The charge failed to start so I tried the next charge cable with the same result. It wasn't until I sat back in the car that I realised I had left the start/stop button in the 'on' position. It then took a few attempts to turn the car 'off' using the start/stop button. I feared that I had bricked the car, as the HV battery error message appeared on the display. I'm not sure if it was trying to charge with the start/stop button in the 'on' position or trying multiple chargers in quick succession that caused the problem. It might be a combination of the two things.
So, with the bonnet up and a 10mm spanner in my hand ready to try the 12v battery disconnection fix, I asked my wife to connect to the ZS using the iSmart App. I then got her to try and start a charge remotely from the app after I had plugged in the original rapid charge cable, which naturally failed. To my surprise, after turning the car off and back on again using the start/stop button the battery fault had cleared. It might have been a complete coincidence but worth trying to cycle through this procedure if you ever receive the HV battery fault. Ignore having the spanner in your hand and bonnet open as I don't think that part of the procedure helped at all!