I'm in the same boat with my s5. Battery just drains 2% every couple minutes. I did the cache instructions but no real difference after a few reboots. I took out the battery and inspected but all is fine. I am going to try getting a new battery so I can keep the phone as the new ones don't have any additional features I need. I will keep watching this thread though to see if there is a real answer to the excessive drain. While typing this my battery went from 91% to 88%.
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