How can I tell if I need a new battery or a new charging port?

[AC Question]

I have a Galaxy S5 and some water splashed on it today. The charging port was open, and there is a rather large open crack near the front camera, but it didn't seem to be damaged when I texted on it immediately afterwards. When I got off work, it was off and it will register that there is a charger but the charging screen keeps flashing on and off and the phone will only turn on for a few seconds before the screen goes dim (usually on the at&t logo) and then the phone turns off. Is there anyway to tell if that would be caused by the battery or the charging port?

 

[Rukbat]

There's water in the phone. You need a new charging port, probably a new motherboard, and probably some other new parts. It may not pay to repair it. (Replacing almost everything - which you may need - is more expensive than a new phone.) If you have insurance, it usually covers water damage.