Phone Won't charge or turn on?

[AC Question]

So this past week i went to Hawaii. the day before i came back my phones's battery started lasting shorter and shorter times and my phone would only charge when off. A couple of days after coming back from hawaii suddenly my phone started charging just fine again and the battery life seemed to last forever.(thinking it was the humidity) Then, just the day after it started working again i tried to plug my phone in and it showed the charging sign but lost battery life rapidly. Soon it was dead and wont charge at all! even when off! it wont turn on either.
And yes, i did try several different chargers.
My mom also has the same phone and and i switched our batteries, my battery charged fine in her phone and her battery wouldn't charge in my phone. i don't know if that helps but its just more information.
Hoping to get some help from you!
Thanks!

 

[UJ95x]

So is the battery still dying quickly when off the charger or is it just charging slowly?
Could you post a screenshot of your battery stats page?

 

[Rukbat]

I'd say that your humidity guess might be close. It sounds as if your phone's been water damaged. (Bringing a phone filled with hot humid air into a cold air-conditioned hotel causes condensation, which is water. Whether it condenses out of the air or you drop the phone into a glass of it, water damage is water damage.)