Why is my Iphone not holding a charge after it has been on the charger all day?

It tays on while it is on the charger but after disconnection it turns off. I did drop it in water months ago so I know this contributed but is it able to continue to hold a charge ever.

Might need to replace battery

Sounds like the charging circuit or the battery is faulty. Dropping it in water may have caused corrosion somewhere.

My iphone did the same, get a new battery and when you take it to the apple store DO NOT say you dropped it in water otherwise you won't get it for free.