Why wont my battery charge?

[AC Question]

Recently I switched phones with my son, both S5. The phone i traded for wont hold a charge more than 60%. What is going on? Is it the phone, which could be expensive or battery?Thanks for any advise

 

[dpham00]

It could be a battery calibration issue, if so I would let it drain completely and recharge to see if it would go to 100%. Otherwise it is probably a bad battery