Please add Di2 battery level

Hi,

Just downloaded the program and loving it!  Thank you for all the work.  But it would be really nice to have the Di2 battery level in %.  This field is found under the Edge 830 list of standard fields.  It would awesome if this change can be incorporated into the next release.  Thank you.

Also, I'm having a problem with the preview screen go blank while I'm building the screen.  Clicking on 'refresh' doesn't solve the problem.  To make the preview show up I have to close and reopen the program.  I'm not sure if this is a bug in the program or something in my PC that is causing it.  I'm running Windows 10.  Thanks.

Jonathan