reply to shdesigns
Re: effect of high charging current on NiMHs Yeah, incorrect/outdated specs for the batteries were one possibility I was thinking of.
I did some more search on optimal charging rate for NiMH, and stumbled onto this:
A very good thread, unfortunately, most of the cited material is now 404.
In any case, I concluded the following:
a) 0.5C - 1C is used partly because detecting completion is most reliable in that range (and also because the charging is reasonably fast)
b) if a charger is going much over 1C, the life and cycle time of the batteries may plummet
c) 0.1C may put in more charge with less stress, but it's much easier to miss completion at such a low rate, and overcharging is bad, even at such a low current
Looks to me NiMH charging is actually much more SW than HW, and so I may just try to roll my own charger when I get some spare time.
Wacky Races 2012!