According to Apple, some of the USB-C charge cables included with the MacBook or sold separately through June 2015 might fail because of a design issue. The MacBook may not charge or only charge intermittently when connected to a power adapter with an affected cable.
Fortunately, Apple is providing free replacement cables to eligible customers. If you think you might qualify, see Apple’s support page for more information on getting your replacement cable. Some customers have reported that they have already received the replacement cable from Apple.
Related article: The History of USB … It’s Not Quite As Simple As 1, 2, 3
And if you’re looking to bring new capabilities to your 12” Retina MacBook, be sure to check out MacSales.com’s selection of USB-C cables and accessories including the OWC USB-C Dock!