After experiencing very solid battery performance on my LG G2, battery use increased suddenly yesterday, seemingly due to Google Play Services. I had just switched off wifi in the background (when wifi is not available), so my question is whether Google may switch to GPS when wifi is blocked?? Anyway, after switching wifi back on, Google Play Services now seems to be back to normal (3% of battery use last 3 hrs vs. 30% yesterday). Maybe worthwhile checking out.