Lithium Iron batteries are also know as "LiFe Packs", "A123 Packs", "A123 Racing", "Lithium Iron Nanophosphate", and "Lithium Phosphate". They are different from Lithium polymer batteries in that the cell voltage is nominally 3.3V for Lithium Iron versus 3.7V for Lithium Polymer. Make sure you use a charger that supports Lithium Iron (LiFe) batteries or you may damage the battery or worse.
There are three methods to power your receiver and servos. One method is to just use the
Battery Eliminator Circuit (BEC) that is part of your
Electronic Speed Controller (ESC). If the ESC does not have a BEC, or if the power is for a non-electric powered model, then you will need a separate battery. Below are receiver packs you can use directly. Since servos run on either 4.8V or 6V, a two cell Lipo (7.4V) alone is high of a voltage for a receiver pack and may cause damage. The LiFe packs below are 6.6V packs with a Futaba J-Connector you can plug directly into your receiver.
The third and final method is to use a 7.4V two cell LiPo pack and a
Battery Eliminator Circuit (BEC).
Prices, product specifications, and product availability are subject to change without notice.