I have a few PRO/TEK 5 Cell 1600mah NIMH receiver packs. These are what I use and have used to power the electronics in my truggies. I have a few questions...
Just as a matter of reference I am a club/entry level racer with 20+ years of experience in R/C. I am about to launch a brand new RC8T Champ Ed. and want to make sure I have the best and proper electronics in my truck.
I use a Hitec 5955 to steer and a JR Z9100S to go. I will try to use these through most of this race season and maybe upgrade next spring.
1. What is the best way to keep these NIMH battery packs charged to their full potential? Right now I am using the charging lead on my Spektrum receiver and/or a basic wall charger. I charge the batteries until they are warm in my hand and then go run them. I usually charge overnight before I go racing. I normally get 4-5 tanks out of 1 pack before I swap but I have NO idea if that is good or bad or what. I just swap to be safe.
2. Is there an inexpensive but better charger/charging method I can use to keep these batteries fresh and powerful?
3. At the end of last race season I took these out of my truck and they have just sat. They were not discharged. Is that a problem? Should I somehow cycle these batteries?
4. LIPO: I am interested in this battery technology but it is very confusing and I am not sure if I should even venture into this realm...? Pros? Cons? Costs? I know its an initial investment in batteries, chargers, etc. I wouldnt even know where to start. There is so much LIPE tech talk out there right now.
Thanks...

The only optimal charge for NiMh batts is some kind of peak detecting charge where the charger senses the small characteristic rise in voltage as the cells become fully charged. You can't match this with a wall type charger no matter how long you allow it to charge.

The 2/3a cells that are used in rx packs don't like charging at more than 1amp and life and performance will suffer charging at more than 1amp. I charge mine 1400s and 1600mah rx pacs at 0.5amp and only charge at 1amp when I'm pinched for time.

This is a decent, cheap charger and can balance charge lipo when you get there -

http://www.hobbypartz.com/thac6smbachw.html

NiMh are supposed to be stoed charged and cycled one a month to best maintain them. You will need to cycle them until you see the disch mah stabilize. Would be best to start with what is known as a forming charge - a low rate, very long charge to wake them up, something like 16hrs at 160ma. Then cycle them and see what kind of disch numbers the pacs puts up. If I don't run mine every month, it takes 2 or 3 cycles to get them back cycling them at 0.5a disch, 0.5a charge.