Why is my battery draining so fast?

[AC Question]

Okay so i bought a Samsung Galaxy Note 4 about a year and a half ago and the battery has been doing this thing for a while now. it will show that i have 45% battery left and as I am watching it the battery percentage drops so fast. it will say 45% and then instead of going like a normal battery and going 44% it will just drop strait down to 15% or even lower and then before i can stand up and walk the two feet to my charger it will die. sometimes i get my portable charger plugged in after it dies and it will say 1-3% while it's still shut off so i turn it back on and then it says 44% again. i dont know what to do with it. this whole cycle happens within ten minutes and almost always happens once the battery life drops below 50%. sometimes it will be nice and let me get to 25% before it shuts down.

is there something wrong with the phone? should i just buy a new battery? I had to have the screen replaced a few months ago but i don't think that should have done anything to the battery, should it?

 

[nahoku]

Whether or not the screen replacement now affects your battery life would be pure conjecture. My first guess would be the battery. They're cheap enough on Amazon. Some people like the Anker batteries... 2 batteries with a charger = $29. I went with the Samsung/charger combo myself. Check out Amazon.