RE: Hitec X4 programing NiCd in Auto
If your pack is getting extremely warm then definitely check the delta peak and lower it some. (It should be set to "default" from the factory.) My packs typically rise some 15 degs F before shutoff but only right at the very end of charge say the last 5 minutes or so. I've had absolutely NO trouble out of mine. Also, my Accucycle Elite gets the pack warmer than my X4 does although neither let it get warm enough to damage it.
P.S. The process for changing from "Man" to "Auto" is tricky. It involves pressing the Start/Enter key and while holding it pressing the inc/dec keys simultaneously. It takes some playing around but it will go there with some patience. I don't use auto with NiXX packs at all on mine.