S3 battery problem

[hafmb]

Hi guys, so I fully charged my s3 and it took more than 5 hours for that. I even got the fully charged notification however when i unplugged it said low battery less than 5% and few seconds later it died. I ordered a new noot battery. Is it the battery or the phone that is messed up?
currently im using s4 charger because my usb wouldn't work and the s4 charger only works at home which is very weird.
help pleaseee:-\

 

[B. Diddy]

Welcome to Android Central! Sounds like a failing battery. Let us know if the new battery works.

 

[hafmb]

It doesn't! takes forever and shows different battery percentages at times

 

[B. Diddy]

The new battery does the same thing? It must be the phone, then. You might have to do a factory reset. Also check the battery contacts to make sure they're not dirty.