True, although there seem to be an awful lot of individual cell monitoring ICs out there these days... even from those folks like Maxim.
Plus I'm told that lithium ion, in particular, parallels quite nicely compared to NiCads/NiMHs -- that you can even ignore individual cell monitoring in some cases without much risk.
"The voltage change isn't a big deal. You build up a strings of batteries then buck convert to whatever you need."
Yeah, but if you're looking for the best efficiency it is harder to build a buck converter that operates over a 4:1 input range rather than the 1.25:1 that a single string gives you.
Still, I don't claim to actually know what I'm talking about here. :-)
Here's a list of a bunch of HP batteries and their rated voltages:
3, 6, and 9 cell packs all claim to be 10.8V or 11.1V, whereas the 4, 8, and
12 cell packs all claim to be 14.8V.