After Replacing Battery, Battery Won't Charge

I just replaced my Iphone 3gs battery. I put the phone back together the battery was read, and it was at 45%. I plugged it into charge and the battery would not take a charge. The battery is now dead and everytime I plug it in it will start up then immediately power off. Itunes reads the iphone I manged to put it into restore mode, and restore it while dead but that did nothing. It's now restored but the battery still won't charge. I took it all back apart to ensure everything was connected properly and it still won't charge. I was reading on here about a battery charging fuse and was curious. Though when my phone was on the vibrate function did work. The phone charged before i replaced the battery. And yes I tried the simple stuff such as using a number of different chargers and still nothing. Please help.