Just bought this battery from amazon,
https://www.amazon.com/gp/product/B01IOJSN3E/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
ive been playing music and its been holding charge more than the battery that was in there.
i will let battery drain zero and then charge it up and see how it holds up. It came charged at 33 and after 30 minutes of use its at 30 % ..
im excited to see the results, the battery was $13 USD and got delivered in two days, came in a yellow bubbled envelope and the battery was in a little box that said nexus 6p
one thing i noticed was that the flex cable was running from the bottom of the battery as opposed to the OEM that ran on top of the battery, it sits well, but honestly i did see a gap in size. the OEM battery actually filled in the whole compartment and the after market one left some space. i attached it and now im using the phone outside in the cold (im in Riverside CA) and its raining outside, and it seems to be holding up..
opening the phone wasnt hard, got the needed tools from a local dollar store, phillips precision screw driver, a hobby blade kit and it was super simple to open.