there shouldn't be too much of an issue with space, with the g&g, there might actually be too much space cause even my 8 cell 4000 mah nimh can shift around inside the stock. What I need to determine at this point is the power draw for the 2 different guns to find the right battery. Since I'm a firm believer in not halfassing things that can be dangerous, I'll have a good charger that can balance charge.
The rest of the stuff like the triggermaster should give good warning that the battery is dry enough for a charge.
What's the usual method of determining how much power a motor draws? Once I find out the draw I should be able to pick a battery that puts out enough amps for the strongest motor of the 2 and I should be fine, right?