With some clever wiring you can set it up so that with 2 5S packs one powers each drive motor and they both power the weapon. You would need 2 links and high discharge lipos but it would give you the 2 voltages in the same system. the atlernative is two totally independent systems like in Binky & Conker: binky running a 2.6Ah 4S for drive and 2x 2.6Ah 5S for weapon. Conker has 1x 3.3Ah 4S for drive and 2x 2.7Ah 6S for the weapon.