unable to charge new battery

After installing my new battery my phone won't charge. I have tried a force restart but nothing works. During the replacement, when I took the battery holder off and removed the battery connection, another component was stuck to the battery holder, It had a small disc at the end of a wire and appeared to fit in a socket receptor adjacent to the screw receptor furthest from the edge of the battery. I replaced this but wonder if it might be broken.

The old battery sometimes wouldn't charge if I didnt have the connector in firmly. However, when charged the battery wouldn't hold the charge for more than a couple of hours. When I connect to the charge port now my iphone isn't recognized on my computer so I must have done damage when I changed the battery. The only problem I had was that when I pulled off the battery holder the wire with the connector came with it as well as another wire that was lifted out of it's socket. I don't know what the latter was for but suspect that is the issue.