eScreen Battery Level -1?

I was looking around at some diagnostics researching my phone battery life and I stumbled across the engineering screen (used for people who want to turn off 4G/LTE) and I noticed that on the diagnostic screen it says "Battery Level -1" for me. To see this, go to browser and type in "escreen://" (as stated in this tutorial: How to access the engineering (Help Me!) screen on BlackBerry 10 | CrackBerry.com)

Does anyone else have this? Does anyone know what this mean?