Why does my battery drain so fast now?

[AC Question]

Galaxy S5. Ok, so my phone had been acting up and running stupid slow (not all the time, but at random) frequently over the course of the week or so. It picked a bad time to act up again and I ended up punching the screen while screaming obscenities at it. I don't often get that angry, but IIRC several things were adding up to fuel my temper, and very occasionally something gets brutalized, like, the whole reason I have the S5 is cuz my S3 was thrown off a 12 ft ladder onto a concrete parking lot. Anyway...When my S5 got punched, the battery life was at like 40%. It instantly reset itself and once booted back up, was at 2%. And ever since then even when it charges over night, it seems to be normal to get from 100 down to around 40%, but once at 40, it will be at 15-10 and sometimes even lower in no time flat. I was just wondering why that may be, and if it is coincidental that it was JUST after it taking a blow to the face, and what may be done to help fix that problem. Also, not sure if it may be related to a recurring issue, but the reason it likely was abused was because it has been quite slow in the past couple months when running off mobile data, not sure if it may be my device or Verizon...but it seems to be anywhere at random, and when I am in areas that it never seemed to run slow before and that I still have very strong phone signal.

 

[chanchan05]

The S5 is a 2 year old phone. If the battery is 2 years old as well, this is to be expected. Just get a new battery.