Thanks, that is useful. My system is of my own design and I did not get to implement yet an add-on for charging USB devices. On the list of things to do, but low priority.
No worries, just to be clear should have said when I fall below 7 kmph at night with my lights on (up steep'ish hills) I get a message about lost connection with charger (on the Edge 800 screen).
From memory my Sondelux setup used to give no message but my headlight would dim.
Not sure why the symptoms are different as I didnt have a dynamo tail-light with my Moulton.
Just the Edelux and E-werk, cache battery and Edge 800.