My main computer is my iMac. It seemed like every time I opened my MacBook Pro, it would show this screen:
So I researched a bit and fixed it. Here's what I did:
- Turn off "PowerNap while on battery power". This is the Energy preference pane.
- Turn off "Allow Bluetooth devices to wake this computer". This is in the Bluetooth preference pane under Advanced.
That's it.
Now, when I open my MacBook the battery has barely moved from the previous day. For example, 3 days ago I closed my laptop with 64% battery. I opened it this morning with 50% battery. A 5%/day battery drain is excellent for a computer that's keeping its running memory actively powered. Previously I'd see what seemed to be 5%/hour (I didn't actually measure it but rarely did I open my laptop and it wasn't dead).
If you want to track your battery usage, check out iStat Menus. It has a graph to show battery drain over time (past hour, day, week, month).