So my new rMBP is just under two weeks old & I have calibrated the battery today. Something I'm finding weird is that the battery remaining percentage is showing as one value in the system display & then any other third party apps are showing a different value. For example, at the moment the OS is showing %age as 96%. However two separate apps that show battery status are showing it around 91%. Battery Health iStat Pro As I said I've calibrated & also reset the SMC. Any reason this could be happening or is it normal?