I have an Anker 20100 USB-C charger, yes, it works on my MacBook 12". It won't charge a 15" for sure...however, I have a 13" sitting here with me. I'll plug it and report back shortly
[doublepost=1481094747][/doublepost]Update: 7 minutes on the Anker charger. Started at 59%, ended at 59%. I provides enough power to "maintain" while working. I may try it when it's in sleep mode. It's not like with the MB12" which works like a normal charger.
Anker link at Amazon. They updated the description to state "MacBook Compatibility: In addition to standard functionality, USB-C port makes it compatible with the new MacBook 2015/2016 (not MacBook Pro), charging at 5V/3A"