Chosen Solution
I just received the iFixit battery that I ordered for my iPhone X. When I put it into the phone and plugged it in, the phone did not turn on. When I plugged it into the power brick, the phone started bootlooping. When I plugged in the old battery to the phone, the phone worked fine. Is the battery i ordered defective or is there something I need to do? Update (07/19/2021) Edit: The battery began working after cleaning the connector.
There could be a chance it’s defective. If you have a volt meter you can probe the battery contacts in the connector to get a voltage reading.
