New battery, but won’t charge

I purchased a new battery kit from you and I’m running it some issues. The old battery gave me the green snake even after a reboot. The new battery acts as if the iwatch can’t see it and won’t charge. It just flashes the apple logo. I left it over night same thing. I took the battery completely out and it’s doing the exact same thing without it. With the battery in it acts like it can’t see it. I put the old battery back in and it goes to the green snake and no logo.