ORIGINAL: flatspinjim
You don't have to run regulators with the A123s. They run a constant 6.6 volts without a drop off, but when they do drop off, it's sudden. The thing I like about the A123s is they put out over 30 amps, which means when you do a hard snap, or a really violent menuver you don't have to worry about your voltage or amperage dropping. They also recharge in about 15 minutes. In my 35%er I can get in 6 ten minute flights before I think about recharging
10-14kg-cm torque digital servos (such as Hitec 5645MG, 7985MG..) wont draw more than 2 Amps
Peak.. If they are locked, they draw about 1.8-2 amps maximum. So even if you were to lock 5 servos at once in a 30% aircraft (which would
never happen if you chose proper servos for the aircraft) they would draw total of 10 amps peak, momentarily.
The 22 awg "HD" servo cables are able to carry 3-3.5 amps continuous, and able to carry 5 Amps for a short period of time (measured in seconds) before getting warm and increase internal resistance.
Current LiPo cells are able to pump out 20-25 even 30C, that is in general 30-45 amps continuous draw for a 2000mah pack. A123 cell's only advantage is they can be used without a regulator and can be charged faster than LiPos. LiPos are cheap, lightweight and keep their balance well nowadays even if charged without balancer and dont lose their capacity in a short period. BTW some people are using LiPos directly without regs, without any problems and now some of the newer servos are directly compatible with 7.4V input voltage.
Back on the engine subject, I think running a walbro carbed gasser rich on top end is useless, and harmful in the long run, as it promotes carbon build-up, lower performance and plug fouling. One should run them as intended by the engine and oil manufacturer - 32:1 with mineral and 50:1 with synthetic with adequate cooling.