I replaced the battery (from ifixit) and it won't hold a charge.

I replaced the battery (from ifixit) and it won't hold a charge. Hi, I replaced the battery in my 20 month old fitbit blaze because it wouldn’t hold a charge. I followed all the instructions, let it discharge down to 1 bar and then charged it up. It still won’t hold a charge for more than a day now. It was like 5 days when new. Is this thing trash?