Do nicad rec. packs need to be discharged?
No. Battery cycling should be done when it warrants, like if you do not fly during the winter season. Charge the batteries, discharge then recharge once a month.
The better solution is to install a "trickle" device between the wall charger and connectors. The Ace Auto Add-A-Trickle will work fine. It's easy to install and is automatic. Once you have the batteries charged for the normal period (18 to 20 hours) the unit will automatically switch to a trickle current. Leave the radio connected until you go fly. After your flying session, recharge the radio normally and the unit will recharge then go into the trickle mode. This way your batteries will always be in top shape reqdy for the next flying session. FMI do an internet search for Red's R/C Battery Clinic. You will find all you answers there.