Why go to all that much trouble and weight (4 cells) just to get what you would have had originally with a single C cell alkaline?

It ain't broke, so don't fix it.

If you thing you need more flight time, simply use a D cell alkaline instead of a C cell and you'll get something like around 2500mah or more of reserve power at 1.5 volts.

Now, if you're asking the question because you want to use your flight pack as a power source for your glo igniter at the same time, well... bad idea.

Highflight