Hi-Energy 2S 3450mAh 10C Li-Fe RX Hi-Energy O-HE2SFE345010R is specifically intended to be used for powering model flight controls such as recievers, servos and gyros in larger models. The robust nature of Li-Fe technology makes it ideal for this application and the nominal voltage of 6.6v means that in most situations, the electronics do not need to be HV compliant. It is wise to check that all your electronics can cope with this voltage as some will only tolerate 5v.
Unlike Nimh packs, Li-Fe is much less prone to self discharge but it does need a charger designed to cater for this battery chemistry. Most of our latest Sigma EQ chargers do.