battery only lasts 6 hours!! pls help!

[potatolove]

i've bought this phone a month or two ago and all i've done to it was unlock it (its from sprint) so i can use it in canada.

I have done absolutely nothing else to it, and all i do with my phone is call and text. i dont do any email check or whatever so all of that data stuff is off. i've tried the simple stuff like setting the brightness to like 40 %?

i dont know anything about this technology stuff and i dont use or need the phone to do anything else really but text and call

i thought it was normal for my phone to only last 6 hours until i bumped into a friend and his phone lasts 2 days!

im just wondering what is wrong? is there any way i can fix it?

thank you!

p.s i have spent time reading in the forum but i dont understand half the stuff mentioned because im new to the terminology and stuff sorry!