I can understand how it would be frustrating for your device to power off when the batter is still showing a charge, LISCAR39.
This certainly isn't how you should expect your phone to perform. Are you seeing any error messages on your device? Do you recall any changes just before this issue started? Are you experiencing any issue with the touch screen or physical buttons in addition to your device powering off?
Please run a Device Health Check: http://vz.to/2wDwhVR . Are you seeing any alerts once this has been completed?
Follow us on TWITTER @VZWSupport
If my response answered your question please click the _Correct Answer_ button under my response. This ensures others can benefit from our conversation. Thanks in advance for your help with this!!