How to maximize battery life on the BlackBerry KEY2
* Open your Settings Menu, and tap on Battery.
* Tap on Battery Saver. Set it to turn on automatically at 15%. You can also enable it now, if you like.
* Turn off Adaptive brightness and disable Ambient display.
* Set your device to sleep after 15 seconds of inactivity.
* Open Display Settings. Reduce Brightness level to the minimum.
* Turn off keyboard brightness optimization. Turn down both keyboard and backlight brightness.
* Tap on Apps & Notifications. Remember your battery-gorging apps? Let's do something about them.
* First, uninstall any apps you don't use frequently.
* For each app, disable Background Data
* For each app, tap on Battery Usage, then Battery Optimization. Make sure the app is set to "Optimize."
* Navigate to Connected Devices. Disable Bluetooth and NFC.
* Do away with any widgets you don't need, and keep your wallpaper simple. Your best option is a solid black background.
Naturally, you don't have to follow all of the advice here and in some cases, you won't want to. These are just the steps to get the absolute most of your battery. You can pick and choose as you see fit!