I've been using a plug like this ( https://www.amazon.co.uk/Charger-Syncwire-4-Port-Interchangeable-Adaptor-White/dp/B011KPRE1G/ref=sr_1_7?ie=UTF8&qid=150635523

I've been using a plug like this ( https://www.amazon.co.uk/Charger-Syncwire-4-Port-Interchangeable-Adaptor-White/dp/B011KPRE1G/ref=sr_1_7?ie=UTF8&qid=1506355234&sr=8-7&keywords=usb+plug https://www.amazon.co.uk/Charger-Syncwire-4-Port-Interchange... )for my phone/watch/headphone/kindle charging for years. It's very handy - especially when travelling.