These are some tips on how to improve the battery life (and avoid overheating) of your BlackBerry 10 smartphone.
Update to the latest OS
Ensure you have the latest BlackBerry 10 OS version for your device, as updates can include improved battery management and performance. To check for updates, go to Settings > Software Updates.
Use the correct charger
Utilize the official BlackBerry charger that came with your device as this has been optimized to deliver the correct charge for your BlackBerry 10 smartphone.
Charge correctly
Regularly allowing the battery to fully discharge down to empty is not recommended for lithium-ion (Li-ion) based batteries (the type found in your mobile phone) and will likely shorten the battery life. Li-ion batteries are designed to be charged frequently. The preferred approach is for shallow discharging before recharging, to prolong the battery life. However, it is better to charge for extended periods of time rather than for very short bursts (i.e. less than 15 minutes).
Turn off unused connections
Though the radios on BlackBerry 10 are designed to be efficient, you may notice an improvement in battery life by turning off any network connections that you aren't using, for example, Wi-Fi, NFC, Bluetooth, 4G/LTE. You can do this in Settings > Network Connections.
Adjust screen brightness
By dimming the display brightness you can significantly increase the battery life, as the screen is one of the components that uses the most power. To adjust the display brightness, go to Settings > Display.
Though there is no "auto-dim" setting, the BlackBerry 10 does feature an algorithm to optimize the backlight level.
Turn screen off
When not in use, it's always a good idea to turn off the screen to conserve battery power. You can do this by pressing the Power/Lock button at the top of your BlackBerry 10 smartphone.
Also lowering the Screen Lock Timeout in Settings > Display will turn the screen off quicker after being left idle.
Another battery saving tip is to switch off Allow Gestures when Locked, if you don't mind using the Power button to unlock the device.
Manage accounts
In the Settings > Accounts section you can add, edit or remove accounts such as email, calendar, contacts, Twitter, Facebook etc. These accounts use battery power to stay updated so it's advisable to remove any that aren't regularly used or required.
Use Push Email
Whenever possible, choose IMAP or Active Sync when setting up a new email account. These typically use push delivery mechanism, a more efficient method than the POP protocol which has to regularly check for new messages. If push email isn't available or supported with your email account and you don't need instant notification, you can increase the interval between checking emails to improve battery performance.
Customize Notifications
You can setup your Notifications in Settings to conserve battery. For example ringtone sounds and vibrate will use more power than just having LED notifications. You can also enable Bedside Mode by swiping down from the top of the screen after locking your screen. This is a quick and easy way to turn off all notifications for when you don't want or need to be notified, for example, overnight.
Third-party apps
Ensure you close any apps that don't need running in the background, when you are finished using them. Also check the app settings for anything that might improve battery life, for example, the refresh intervals on social media, weather or news apps. Try reducing any refresh settings on apps that maintain active connections to services or data.
Overheating
Excluding faulty hardware or outside temperatures, overheating tends to occur when there is a large demand placed on the device, particularly its processor and battery. You can expect your device to get hotter while playing certain games, or watching videos, for example.
Many of the power saving tips above will help keep your device running cooler, and you can use Charger Alert to warn you if the battery reaches or exceeds a certain temperature.
The recommended maximum operating temperature for the BlackBerry 10 smartphone battery is 35 °C (95 °F) though it is not uncommon for it to run above this, and the device should have a safety mechanism to automatically switch off if it gets dangerously hot.
Remember not to leave your device in extremely cold conditions or in direct sunlight (e.g. your vehicle's dashboard). If you're device continues to regularly overheat when not in use or while charging, consider getting it professionally inspected from the retailer or manufacturer.