After the upgrade to Android 6.0.1 our galaxy s5's had rapid battery drain - less than 8 hours from 100% to 0 - idle except for the occasional call on my wife's phone - 1 call on my phone. Went to the Verizon store and I will never do that again - he said phone was too old, needs new battery and NOT helpful at all. I played around resetting cache, then phone back to factory defaults to no avail. I then turned off my wifi and now it is working normal 3 to 4 days of battery with moderate use. I had replaced the new battery with the old as there was no difference. I had tried all the different remedies I saw on line to my phone only. When I turned of the wifi connection and battery usage returned to normal I did that to my wife's galaxy s5 and got the same result - normal battery drain. I wonder what turning off the wifi did. Is