look at [url=http://www.rcpilot.eu] . They offer new concept for charging battery pack of A123 cells. The battery is divided into subpacks during charge to save energy from power source. One charger can support up to 4 subpacks. After charging the subpacks, they can be connected in varios combinations to provide different voltage and capacity.
Charge and balance process for battery 12S2P takes only 10-15 minutes at 10A charge current per subpack.
Also they provide kits for battery assembly compatible to their chargers.
Some pictures from website: