unsupported battery.....

Buy a battery that is supported. Hate to say it, but if you bought a super cheap extended life battery, you're risking some damage to your phone. If the phone is refusing to charge it, there is probably a good reason for it.

 

How long did you attempt to charge it for? I had the same issue with my extended life battery, at first, too. Upon placing the batter and new backing on my phone I tried to charge it and even turn it on, but to no avail. While it was sitting on my desk with the charger plugged in, I was attempting to write a letter to the person who sold it to me about a refund when out of nowhere the phone turned on and was charging fine.

Have you tried letting it sit on the charger for at least 10 minutes?