My experience with NiCd vs. NiMH packs covers the transition period between the two.
My general observations are that if you don't run the device down until it quits and have the means to do a 14-16hr charge of the pack periodically, so as to balance the cells, NiMH packs work well. If you frequently run the device down until it quits, NiCd packs work better, and also generally have a much longer calendar life. Actually, being able to do a 14-16hr charge on either chemistry once in a while is very beneficial.
That said, it really equals out pretty much. You have to charge NiCd packs more often, obviously, but in the end you probably get more accumulated mAh out of them. With the NiMH packs, you don't have to charge nearly as often, but they don't last as long. This is particularly true if the pack is run down to a low enough level that either over discharges a cell or cells, and/or a reverse charge of a cell or cells occurs. The former not really having any effect on NiCd's and the later, NiCd's being much more tolerant of.
The idea of building an LSD pack may be the ideal solution. I have no experience with LSD welded or soldered packs, but that might work out well.
Dave
