A quick note to remember is that the 4.8 volt pack is the "nominal" voltage at 1.2 volts per cell. A fully charged pack will reach about 1.4 volts per cell and top off around 5.6 volts. The same goes for a 7.2 volt lipoly. That voltage is for the normal voltage, however, fully charged lipoly cells reach 4 volts each and you would be putting 8 volts to your RX - that is too much.

So, the simple solution I use: The max I go is a 5-cell RX pack (6-volt) that will max out about 7 volts. or if using Lipoly for the RX, install a regulator.

Please note, you are talking to an Old JR radio guy who stil prefers using 4.8 volt NiCd's in his planes