The LED lights that run off a battery is basically what you get when you order the IR sky screen set for a CED Millenium chrono. The catch is... they are IR, so you can't tell if its on or not.
CED attempts to get around this by putting some visible red/green leds inline to show battery status, etc. They don't really light up enough to be visible (for me).
Being pretty far north (for the continental USA, not counting Alaska of course!) we get some steep sunlight angles... the sky screen shades don't do much good, and sometimes even with the IR lighting I have problems clocking shots - I think the direct sunlight coming in at such a steep angle interferes with the weaker (relatively) IR lighting coming straight down. Then again, I might be all wet on this one. I'm sure there's a lighting guru out there just waiting to chime in...
A few years ago I'd chatted with some action pistol shooters, and they described the chrono box they used at matches to certify guns as 'major' or 'minor' power levels... basically a plywood box with two CED Milleniums back to back, and interior lighting (incandescent, as they had 110VAC handy at the range).
Sounded like a neat idea, and the wife got me a heavy duty surveyors tripod from HD last Christmas... I was going to build my chrono box, but now I need new side screens because the wiring jacks are hosed.
The ez-up pop-up sun shade sounds like it might be a good bit easier...