There is one exception and that is the new LiFe packs... Lithium Iron Phosphate packs, which have a nominal voltage of 3.3 per cell. The packs are 2 cells which means nominal 6.6 volts per cell and are stated to be able to be used as direct replacement for 5 cell LiPo or NiMh packs. They are lighter and have a sufficient C rating to be used to power receivers and servos.

One caution, though, they require a specific type of charger.

Check them out at Tower Hobbies at the following link:

http://www3.towerhobbies.com/cgi-bin...&I=LXYAS8&P=ML

These are 1800 mah two cell packs.

CGr.