@emsenn @ajroach42 @djsundog the pi 3 won't run on adafruit's battery circuit since it maxes out at 1W. When I tried it I had to fall back to the pi 2, and even that got less than an hour on the lipoly I had.
I've read that HDMI has a lot more overhead than LVDS because of the encoding/decoding process it needs to support the HDMI spec's DRM requirements.