Respuesta a "Replaced iPhone battery but it won't charge?"The fact the old battery charges, implies there is something wrong with the new one. I'd try and get the seller to refund/replace it.
Respuesta a "I did the Replacement, now it dies immediately if off the charger"Shorting a battery can cause irreversible damage to the cells. Also check for a voltage directly from the battery pack, if there isn't one then it could have become so discharged that the safety circuit has cut in. A short manual charge of the cell itself might revive it. Working with batteries can be dangerous, be extremely cautious!