BlackBerry's trackball is very weak, you need to clean your hand first before roll the trackball. Do not use the wet hands. Make sure you don't press it too strong. Oil and some sticky things will break the trackball. There is another way how to avoid using trackball by using some shortcut tricks.
Also, BlackBerry's battery is not strong, charge your battery as long as possible and avoid charging in unstable electric source, using wall or computer charger is recommended. By plug the USB port from BlackBerry to computer, the battery will be charged.
If you send or receive the call, try to reduce the volume and do not use sound equalizer, headset will help you how to safe the battery power.
Reducing the backlight timeout and brightness will also help, the battery would be not powering much for the screen, disabling the key tone or trackball sound are recommended.
Do not forget to turn off unused connection (e.g. GPS, Wi-Fi®, Bluetooth®), also turn off the phone connection with the SIM card provider when you are out of signal coverage. If you turn it on while you are out of signal coverage, the BlackBerry would be trying to find the signal and it is drying the battery.
Disabling audio and LED notification also will help. Including turning off the LED signal coverage.
