Based on my usage. There is no way that my battery should be sub 80%. Please note that I used Amazon Video last night not after the most recent full charge. Apple Store said diagnostics showed that my battery was fine. Said that NFC being on constantly could be causing the drain. Great. So I suppose apple wants me to disable another feature that I want to use. And of course their is no way to turn the NFC chip on and off based upon use, so it's like looking for a credit card terminal to read. May be the last iPhone i get for awhile and I have had every whole number device.