New battery doesn't seem to want to hold a charge

New battery doesn't seem to want to hold a charge

I ordered and followed the video instructions to replace the iPhone battery for a series 1. I also replaced the adhesive strip and the pressure band. The battery was at 0% so I charged it until it was at 100%, then gave it to my mother. The battery does not seem to want to hold a charge for more then a couple of hours. It's not getting much of a workout with my 80 year old mom, it's mostly keeps time and helps her find her phone.