What are the best way for my cellphone battery last longer?

it's better if your mobile phone won't be displayed under the heat of the sun. try to have it drained atleast once a week before charging it. this techniques help me when i want to make my mobile phone's battery last longer.

These days most batteries are charged in the factory, so when you get them just charge them for a couple of hours. Also, with modern batteries (Lithium Iron) try not to let the battery drain all the way out like you used to with the old Ni Cad batts of old. The battery has no memory and last longer when you just charge it when you remember, if its half way done and you are at home for 30 mins, plug it in. After a year I still get 2 full days use out of mine and that's what I'm looking for. Your usage may warrant more, but if you can't get to a power source in 48 hours, I'm guessing you have other issues to worry about ;)

Don't leave your cellphone sitting in the cold, like your car etc.