I have a new Macbook Air 11" (mid2013). Everything was fine until the upgrade of SMC firmware to version 2.0. It shows installed 4 or 5 times. After the last one i'm having problems with the battery. Suddenly it shows the message "Not Charging" or "Replace Now".
I reset the SMC but nothing changes. I'm using it connected to the power adapter b/c it's the only way to turn on the machine when it happens, and suddenly it's start to charge normally and if I reset it starts without the power adaptar connected.
Please your help to define if its a software or a hardware issue.