I was about to plan a trip to the Apple Store but I wasn't ready to drop a bomb on repairs because I knew it'd be expensive (it's a 2015 model, so out of warranty). Tried everything you tried but to no avail. I read online to reset the SMC which I did but after doing that the low battery imagine wouldn't appear either. Changed the wall socket and everything but I could feel the static on fingers so knew the charger was fine. After 30 mins, I tried switching it on but it was showing the low battery image so I proceeded to connect my charger but it wouldn't charge. I had used it 30 mins prior to it completely switching off. Last night my Macbook 12' started doing the same thing. The 12-inch Retina display packs a higher resolution than the 13-inch MacBook Air despite being an inch smaller allowing for crisp images and more desktop room.Old topic but just wanted to share my experience as well. Controversially ditching traditional connectivity for a sole USB-C port has allowed for a design that is extremely thin and lightweight, making it the perfect portable companion. Apple boasts that the notebook additionally uses a new 'tiered' battery design to maximize space inside the chassis and delivers 9-10 hours of runtime depending on use. It also packs a lowly 480p FaceTime webcam, a backlit full-size keyboard with a thin 'butterfly mechanism' keyboard design, a clever haptic-capable 'Force Touch' trackpad, and a beautiful 12' TFT LED-backlit active-matrix 'Retina' display (2304x1440 native resolution at 226 ppi). This all is housed in a wafer thin (0.14-0.52 inch), 2.03 pound, aluminum case offered in 'traditional' silver color as well as gold (pictured) and a darker slate 'Space Gray' color option. The MacBook 'Core M' 1.1 12-Inch (Early 2015) features a 14-nm 1.1 GHz Intel 'Core M' processor (M-5Y31) with two independent processor 'cores' on a single chip, a 4 MB level 3 cache, an 'integrated' Intel HD Graphics 5300 graphics processor that shares system memory. However, like the MacBook Air, these MacBook models run OS X rather than the iPad's iOS.

'Reinvented' for the ultimate in portability, the 'Early 2015' MacBook models are even lighter and thinner than the smallest models from the MacBook Air series, and with just one USB-C port for connectivity and a headphone jack, the hardware more resembles an iPad with an attached keyboard than it resembles earlier Apple notebooks.

Macbook air early 2015 motherboard