Charging problem with nexus S

[xBlast]

I had my nexus s for 1 year and a half , now my phone is taking forever to charge , i plugged my cellphone at 2 am last night and it was at 20% Woke up at 12 o'clock and it was a 54...
I changed my battery and my charger (addapter and usb thingy) Is the problem my cellphone ?