There are a few things you can do to help cut down on battery drain.  One of which being turning off Wi-Fi and Bluetooth if you are not using them at that moment. Another being to set the screen sleep time to a lower time than what it is at currently, this will ensure that the screen is not draining power when it does not need to be. You can also activate the battery saver option located in the Battery section of the device settings.

If you need any further assistance with this question, please contact the Sonim Customer Experience Center at 1-833-MY-SONIM (1-833-697-6646) or email us at [email protected].  We are open 24 hours a day, Monday-Friday and we will further assist in troubleshooting.