A123 cells galore..

[suicideneil]

Most half decent lipo chargers can do A123s (Li-fe or Li-ion setting, whichever says 3.7v for the fully charged voltage and 3.3v for the resting voltage), but it does need to be a 6s charger and have a good power output to make the most of that ~5c charge rate potential. 12 of those cells weighs about the same as 7 or 8 nimh cells, which isnt too bad, but still twice as heavy as a similar spec'd lipo, so... personal choice.