Wont charge after battery replacement

Hi guys, just replaced the battery in a ipod touch 5th generation, all went well during the repair. After the repair I found the ipod touch wont charge, it stays where the last usage of the battery.

1. those 3 soldering points, what is the middle point's function? Is that possible that I missed the middle point soldering?

2. Do I have a defect battery? How do I tell? Previously the docking plug works just the battery life sucks.

Thanks all of your input help me to figure this out.