by PegLeg » Fri May 25, 2007 9:49 am
Les
The 8.4 rating on the receiver is for a max. anything less is OK. Most servos (aircraft) have been operating and rated for 4.8v (4 cell) due to the desire to minimize weight.
With larger sail craft where weight of the batteries is less of a factor but the power needs are higher we seem to have drifted to 5 cells (6v). The added voltage gives higher torque and faster speed, the added battery weight usually is placed low for the effect of added "ballast".
Still there are trade offs. I use a 2500 Mah Nimh pack (5 aa cells) in light conditions and a 5 cel 4/5a (4000 mah Nimh)heavier pack in heavier air.
My recomendation is that you worry less about the voltage and concentrate more on the amp capacity of the cells. That is where the "time on water" will come from. Incidentally using the 2500 mah pack I get a full day of racing in most winds.
Good luck