iPhone XS Max smart battery case or mophie for iPhone XS Max

[Alexrat1996]

which do I buy the apple battery cases preowned /used from eBay or do I get the mophie for iPhone XS Max ?

Will either other drop my maximum capacity of the phone battery mines still at 100% ?

 

[Newtons Apple]

which do I buy the apple battery cases preowned /used from eBay or do I get the mophie for iPhone XS Max ?

Will either other drop my maximum capacity of the phone battery mines still at 100% ?

Mine stayed over 100% for a year and 3 months. Was still 100% when I sold it.

 

[Shadowbech]

If you have XS Max I would not worry about capacity being dropped. I have a launch day device and using a smart battery case and my phone still reads 100% till this day. I've read it's the XS (5.8 inch) that are experiencing capacity drop.

However, my XS Max came with 3351 MaH capacity. The actual design capacity the XS Max is 3174 MaH (Per Coconut Battery).