So last night I close the screen as I always do to put the Macbook to sleep, battery was at around 50%. This morning it went completely dead. Since I bought the rMBP a week ago I've always used the 45W Magsafe charger with the Magsafe 2 adapter as I prefer the angled plug. It wouldn't power on at all, though the light on the Magsafe plug turned red so I assume it was charging. So I open the box and opened up the 60W charger. As soon as I plugged it in, it immediately powered on without pressing the power button, but everything was going at a snail's pace. Took a good minute to see the logon prompt, another minute to logon. Activity monitor shows the CPU usage pinned at 100%, so I shut it down which took another minute. Tried again after a few minutes, still slow as a snail. Battery was at 3% at this point. Tried again in a few minutes and the speed came back to normal, the charge was at 5% at this point. So the issues are, what caused the battery to drain in the first place (power nap is off), and why is it so slow until it reached 5% charge. Anyone seen this behavior before?