[folivier]

I think Balqon is the USA distributor for these LiFePO4 cells. But they also will sell to anybody. As such you can get a wholesale price but with very little support. The system I bought from them had a Housepower BMS. Is Balqon producing their own BMS now?
The BMS is basically a board and individual cell sensors that monitor the pack voltage and individual cell voltage. If the voltage exceeds the set point (either high or low) it will shut off the contactor which isolates the pack thus protecting it. A very simple system.
For charging you want to prevent the high voltage from exceeding 14.0vdc. And on discharge you want to prevent the voltage from getting below 12 vdc or so. Again the BMS contactor will isolate the pack if this occurs. Any other control will come from your inverter. On my system (now Richards) the only difficult part was setting the older Freedom inverter to charge it correctly. Again you want to charge at as high an amperage rate as your inverter allows until the amps get down to 10-20 and the voltage starts to rise, shutting off charge at 13.8-14.0 vdc. Float charge voltage is an unknown right now. Some sources say to not float, others say to float at just below the resting voltage which is about 13.3-13.4 vdc.