I've experienced the same thing on my Galaxy S4. I think it eats up battery when it is waiting for you to say "Ok Google." You can turn this off in the settings of Google Now. I've done this and it appears to have helped. I've noticed that Google Search only eats up battery when it is open in the background. Once I close it with the task manager, it stops. And it seems to not be eating all that battery with the "Ok Google" detection turned off. At least it isn't being kept awake (which is it was awake for hours before).
11-28-2013 08:56 PM