recently my phone's battery's been dying when it gets to about 50% T_T i've been using this phone only for about two years

update:
my phone battery is now swollen and the back has come off on its own, rip

@alreadydeadxd
If the back is already off that makes it easy to change the battery.

@FritzAdalis yeah, now i need the money to get a new one T_T no phone for me for a while, lol