My phone is fully charged, then I start using it in the public transports... After 45min, the battery life dropped under 70%. Mobile manufacturers' program the obsolescence of their devices, as well as the components. The main reason for this drop is also the apps that we use on a daily basis, killing the battery life quickly. We've made a short collection of 7 apps that you should use a bit less or turn off when not using it maybe to save your battery.
1# SnapChat
Taking a lot of your mobile's resources: memory usage and battery life. The app can consume a big part of your internal storage if you aren't careful (check by going to settings>mobile data).
2# BBC News
Known as a battery killer, BBC News drains battery life from your phone. Androidpit.com mentioned a solution in its article: Uninstall the app and create a shortcut to the BBC News Website on your home screen. It provides almost the same user's experience.
3# Facebook
Last year, the app was outed for its excessive battery usage. This is due to the fact that Facebook app updates even when running in the background. Thus, fifteen minutes of Facebook, without videos, can use 5MB of Data.
4# Maps
Most users are using Google Maps, this app can destroy your battery life with the use of the GPS location services. In fact, ten minutes of usage can use up to 6MB.
5# Weather App
The app is often refreshed when you change locations or experience changes in the weather itself.
6# Twitter
Like Facebook, Twitter uses a lot of our battery life by refreshing even when running in the background. It helps your feed load faster when you open it but it will drain your battery very quickly.
7# Skype
Exactly like Facebook, Skype doesn't stop the connection to the server when you don't close out the app. Make sure to sign up if you don't want your battery drained and are prevented to unexpected calls on Skype.
Source (c): www.androidpit.com / mashable.com