I'm going to begin using Futaba high voltage receivers and Hitec high voltage servos. Futaba Corp told me that the matchbox cannot use anything highter than a 5 cell pack due to it's voltage limitations. Have any of you used the matchbox with LiFe batteries ? Thanks.

Yes. A I've used matchboxes with 2S A123 packs. They have the same voltage characteristics as a 5 cell NiMH pack.

The LiFe batteries have basically the same voltages as a 5 cell nickel pack as stated above, so you won't really be operating on HV. If you wanted to use direct voltage from say a 2 cell LiIon or LiPo then you need to omit the matchbox and setup everything inside of the transmitter, run the servo leads directly to the receiver.

If you are referring to "matchboxes" which are a JR product, that's one thing
But if you are referring to Futaba's MSA-10, they are rated to run 2s lipo.

This is the Futaba MSA-10 Servo Synchronizer.
Ideal for Giant Scale Models that require multiple-servo control.
If using a LiPo receiver battery, do not use more than 2 cells.

http://www.gpdealera.com/cgi-bin/wga...pgm?I=FUTM4155

Thanks guys, great advice