For a few weeks I've looked for a USB-charger that could keep my 12" Macbook topped up when on the go. But all 2.1 / 2.4 A chargers fall 4-6 Watts short and the battery in the Macbook slowly drains while using, and the charging when closed is real slow. I've gotten best results with a Powergorilla Minigorilla with iPad adapter that slowly puts juice in the Macbook when in my bag. But after looking for 3A chargers online without success, I thought, why not try one of those usually-only-for-android-users-with-huge-phones-quick-charge-things. Since the USB-C charger that comes with the Macbook is way more than 5V, some Android phones have USB-C too, and the Macbook seems to accept most power sources, I thought there might be a small chance of it working. SUCCESS! I'm now powering my Macbook with a (really tiny I might add) Samsung USB charger, and charging with 2-5 Watts at the same time. When the Macbook is closed, it seems to charge as fast as my 15" RMBP with a 60 W (13") Magsafe charger. Now I can leave the 29 W charger at home and use ONE power source for my Macbook, iPhone, Wifi hotspot and bluetooth speaker! Sure, still a clutter of cables, but thats an issue for another time.