I'm actually noticing the same issue but randomly; some days I get almost 20 hours before I hit 20%; others, maybe 12-14 and I'm at 20%. I have also noticed the phone gets hot around the top middle area if I'm in a low signal area and it drops to 3G. It's ironic and funny since I was having the exact same issues on the blackberry Z10...
anyways, wanted to ask..when you mentioned clearing the cache, did I understand you correctly that you also disabled Google now? If so, how would one go about doing that?
Thanks in advance for any help!