Before any talk of discharge, charge, voltages....

What kind of rx pack is it? nicd or mimh? what's the size (mah)?

nicd has memory effects and likes to be discharged after use otherwise they can stop charging fully.

nimh is recommended to always have some charge on it. never let it drain 100%. If you're leaving it charging overnight, make sure the charge is a trickle charger, otherwise it can get hot and explode if overcharged. I always charge my pack the night before a race, irregardless of how much charge is on it at that time. Doesn't hurt it one bit. I even throw it on the charger afte the last qual so i have a full charge for the main.