I've read a few threads about battery drains when closing the lid on MacBooks and thought I'd share a fix that seems to be working for me. The full details can be found here - http://vivekn.com/blog/2014/11/16/yosemite-battery-issues/ The bottom line was the standby delay for my MacBook running Yosemite was 3 hours, i.e. I close my lid and it kept running for 3 hours before fully entering standby. Decreasing this timer has helped a lot. In terminal use pmset -g If your standbydelay is 10800 (seconds) this equates to 3 hours. To set it to a more reasonable 20 minutes use this terminal command sudo pmset -a standbydelay 1200 I've not encountered any problems myself.