My phone is giving me a false percentage?

[nicolejackson2214]

So I have a S3 which I got in February of 2013 and when I first got the phone I never noticed any problems with it dying rapidly but by the end of the school day I'd find my phone almost completely dead with the data left on. So I learned to turn the data off and just leave it to where I could still receive and send texts/phone calls. My mom tossed my phone into our turtle tank and I had problems with the screen when I first fixed it but they eventually went away. Earlier this year I noticed the battery life would not stay at all so I now just keep the phone in airplane mode and just use the wifi. Last month i bought a new battery because throughout May until October, my phone would not charge. It eventually stopped charging on the wall and I thought it was just my charger so I bought a new one, but it would say it's charging while it's actually just draining. I started just using the computer to charge it because if it's plugged into the wall, it won't get to 100% by time I wake up. The new battery is still doing the same thing. Except now my phone will give the green light as if it were at 100, i'll turn on the screen and it'll say 100% but as soon as I take it off it will drop to 90 or 73 or 82. And this past week it's been even lower percentages like 55. I know the phone is old but I have to get a job in order to upgrade so I want to fix it if I can. Do you guys think it's a phone issue itself or just the charging port or ?? I really don't know what else it really could be :/ Any help is appreciated.

 

[Sergiusz Jasper]

So I have a S3 which I got in February of 2013 and when I first got the phone I never noticed any problems with it dying rapidly but by the end of the school day I'd find my phone almost completely dead with the data left on. So I learned to turn the data off and just leave it to where I could still receive and send texts/phone calls. My mom tossed my phone into our turtle tank and I had problems with the screen when I first fixed it but they eventually went away. Earlier this year I noticed the battery life would not stay at all so I now just keep the phone in airplane mode and just use the wifi. Last month i bought a new battery because throughout May until October, my phone would not charge. It eventually stopped charging on the wall and I thought it was just my charger so I bought a new one, but it would say it's charging while it's actually just draining. I started just using the computer to charge it because if it's plugged into the wall, it won't get to 100% by time I wake up. The new battery is still doing the same thing. Except now my phone will give the green light as if it were at 100, i'll turn on the screen and it'll say 100% but as soon as I take it off it will drop to 90 or 73 or 82. And this past week it's been even lower percentages like 55. I know the phone is old but I have to get a job in order to upgrade so I want to fix it if I can. Do you guys think it's a phone issue itself or just the charging port or ?? I really don't know what else it really could be :/ Any help is appreciated.

I would say replacement of the battery should help and is cheap.