I don't know how relevant this is but hopefully it will help someone. I had problems with the moto g not charging when I let the battery get fully drained.It turned out the smart charger wasn't recognising the device and not putting any power to it. Try using a less smart charger - my cheap car one worked & it charged fine. Then it worked fine on my expensive charger thereafter so long as I don't let it run empty. I didn't have to start booting into recovery mode or anything just a normal power up once it had some charge.