[Megazone23]

Another recommendation I would add, which I've read other places as well, is that you might want to consider removing the batteries from the chassis when you charge them.

I believe the reasoning went something like this:
A) If something bad happens, the truck isn't at risk, but you've already figured that one out.
B) By charging the batts in an unrestricted place, it allows the heat from charging to dissipate better.
C) How the heck can you run the truck on another set of batts, if it's holding the charging batts? ;)