A:AnswerThere’s a mini usb (flat) that most Android devices use to charge that also fits into this Apple Watch charger...mine is labeled “DC-IN”. When you plug it in there & connect to any ‘dongle’/usb port, there’s a light that comes on.
So far... I’ve been able to “recharge” my watch (series 2) full from approx. 25% 2 times before needing to recharge this travel charger!