Fisher, you could probably use the night flight module by just simply providing power to the two power pins on the X-port plug (removing it and using the two wires on a servo plug to feed off the plane's power). I think your RX will be providing around 6 volts or so of power. Even giving or taking 2 to 5 volts shouldn't hurt those LEDs in it. You'll not be able to change the LED display modes. Perhaps you could try grounding the input pin wire for a split second and this might be enough to get it to change modes?
On using a watch battery....Why not just take advantage of the plane's battery? Yes, LEDs will take some abuse but the higher the voltage the more hot (and short lived) that may be. I'd just figure out what your input voltage is going to be, then grab enough LEDs at Radio Shack to equal that voltage roughly, then wire them in series. I'm pretty sure that is how it works, or at least I haven't had a problem. If you are using less LEDs then the required voltage input then you'd have to use a resistor to lower the input voltage. But, there are so many LED choices at Radio Shack that I'm sure you can find the right combination and number of LEDs to equal the input voltage. Doesn't have to be close, just within 2 to 4 volts or so.
Just reember that even with the night flight module if you won't have any lights on top of the plane it's VERY hard to see from a distance while turning and showing you the top. You have to get the plane high and above you to keep a good eye on whats going on. I'd put a few LEDS on the wing tips on top of the plane, as well as maybe a light on the nose and at the tail. You could easily use thin wire and some scotch tape to run LEDS all the way out to these tips of the plane.
I would also consider RC-CAMs X-port module adapter that allows you to use X-port modules (Combat, night flight, etc) with standard electronics. You could plug the night flight module into this little do-hickey and then be able to use the full functions of it through your standard RX. He used to have free plans for this but I think he took them off and is now selling this thing for around $30. I plan to buy one to use the combat module with my Brushless Stryker. Going to prey on my friend's stock Challengers, Extremes, and Strykers with my 85mph killing machine.
