You buy yourself a shiny new MacBook Pro Retina, and it comes with a pretty healthy claim on battery life. Especially, taking into account all those pixels that are being pushed around on that gorgeous display. You may also, like me, have noticed over time a pretty sizeable deterioration in your actual battery life. For example; this morning my 13-inch MacBook Pro Retina was showing 2 hours 43 minutes remaining on an 80% charge, and I've been struggling to get much over 3.5 hours total usage before needing a wall outlet. But, a bit of searching around and I found a couple of solutions that should see your battery life return to normal.