Yep, I got it, thanks. Had the flasher show battery percentage once but then decided to abort and switch to a more powerful USB port. It did't go beyond that but when I switched it back it immeidately showed "12%, continuing"

Well, I now know how to flash It ended up too quickly though but I do see the 'Updating SW release. Success' line.

On a side note, flasher is open source, isn't it? Is it not possible to come up with a 'charger' tool that doesn't require a gigabyte image and cannot reflash if you only want to charge? Or is this situation too rare?

Even if it is rare, I think it would be useful to add this procedure description to the first post in this thread for dummies like me.

(Of course, the first thing I myself would answer would be 'do it, people will thank you!' )