Yes but I should read 1.66V so it should be 340. That's why USB seems good and the external power not...
I just tried to power via Vin with 7.4V, and it didn't work. So I tried with much voltage, 11.1, and this time it works ! I just found this weird that it didn't work with 7.4V... Anyway, it seems to work fine with 11.1V coming directly from the LI-PO and not the 5V from ESC's BEC. I hope this is going to continue working !
Thanks !