One of the widgets he showed at -- [node:2725] -- was a battery management module. The instance he showed was for the ThunderSKY batteries. It's a PC board sized correctly to bolt into place on the 90AH ThunderSKY battery cells. But he described some interesting characteristics.
First - it is built to integrate with a larger controller system. Each board has connecting wires for a data bus. I recognized the name but don't remember it, recognized it as a standard I'd seen referenced in embedded microcontroller applications. JT-311 maybe?? Anyway the idea is that each BMS board connects between two battery cells, similar to the way you wire up powercheq units. But because it has a data bus, then there could be a central control unit that gathers data from all the individual BMS units.
Someone asked him if it could be used with other chemistries. He answered that it's not the battery chemistry that's important but the voltage cutoffs. Those determine resistor and other component values, and the design is the same regardless of the chemistry, you simply use different component values for an SLA BMS board versus a thundersky BMS board versus BMS boards for other battery chemistries.
On the ThunderSKY Yahoo!Group they tend to use BMS designed by Reap Systems -- http://www.reapsystems.co.uk/ -- and I just looked and that unit is rather different from the one showed at the meeting yesterday. At yesterday's meeting he mentioned in passing working with Damon Rudman on battery testing and it's possible that's who designed the BMS, since Damon has past experience with battery balancer design.
Another person asked him for the capacity. He answered saying it's a 5W resistor, then someone else did the math in their head and said that means it's a 2A capacity. So clearly the capacity for a BMS unit to shuttle power is based again on the component values.