Hi Don - sorry for the loss. I punched a hole in the ground last weekend with a Quest. Have to blame 3D flying below ground level, not the radio!!
I use 6v receiver batteries made by SR Batteries. They are more expensive but I haven't had a failure and the description of their batteries on their website in my mind is worth the extra $$. I believe 6v also gives more voltage headroom for cell failures. Consider checking your batteries under load. I put a Voltmagic monitor in my "less disposable" airplanes, but checking with a DVM is just as good provided you use one with an adequate internal resistance to simulate a reasonable load on the battery. The Voltmagic can also tell you if the plane was "hit" during the last flight (I think the receiver has to have failsafe feature for this function). I charge with ACE DDVC variable charger, at C/10 for 15 hours before flying. Several times a season I charge/discharge to measure the capacity using a SuperBrain 977. The only thing I don't like about this charger is the display clears 15 minutes after the cycle is over, so you need to be around to catch it. I would look into the Triton for my next cycle/charger. I've been warned not to use a fast cycle/charger for rx packs - better to go slow with something like the DDVC. The H9 Digital Servo/receiver current meter is handy too. You can check charger output, servo drain and other loads with it. If you're using NiMH, they seem to self-discharge much more quickly than NiCd (within a week or so). I stick with NiCd except in really weight sensitive applications. The NiCd seem to be more durable and tolerant. I've had switch harnesses fail. I use the heavy duty ones now, as well as heavy guage/gold plated extension cables.