My MBP is only getting 4-5 hours of battery without having anything open and my maximum battery is degrading rapidly.
Should I try and get a replacement battery or is this normal? My friend who bought the exact same computer as me is getting up to 7 hours of battery per charge. I've reset the SMC and it didn't do anything.

Should I try and get a replacement battery or is this normal? My friend who bought the exact same computer as me is getting up to 7 hours of battery per charge. I've reset the SMC and it didn't do anything.
