The 'genius' said it was dead and could not be repaired...
Sporadic battery issues. Apple genius plugged it into his machine and it said it was unrepairable. I invested $24.99 on a new battery and it is good as new.
I used iFix it step by step and followed the comments by actual users and it went without a hitch. Very simple. I have a background in electronics so for me very simple. For others, it could be moderately difficult.
Don't always assume the geniuses know everything. I went from a $300+ replacement to a $24.99 part.