[reiderM]

Dumb question: How do these balance cells? Do the individual boards drain individually? Otherwise pretty brilliant actually. Short range wireless is easy as heck and low power, and for the manufacturers, saving assembly time is probably a big draw.

This is how most OEM modules work. The balancing circuitry is attached to each module, and a main BMS controller of sorts communicates with this circuitry. Helps reduce wiring complexity and points of failure.

 

[reiderM]

Presumably yes. Although more sophisticated systems are possible, it appears that BMS balancing is normally based on discharging individual cells through bypass resistors, so there's no need for current to flow between the cell and a central BMS device. It is common for modules to be equipped with "slave" BMS units which handle this themselves, only using their connections to the BMS master for coordinating communication; that makes a wireless network a straightforward (although unnecessary) variation on the usual wired network between BMS master and slaves.

My thoughts exactly. What do you gain from wireless? There's really not a lot of wires in a BMS master-slave network, not sure what GM is on about. This seems to be more of a "use big technological words to impress customer" type video.

 

[reiderM]

No, we are on the same page. I'm familiar with how it works in most OEM vehicles currently. Obviously wireless cell taps would be very much impossible (wireless electricity)! I just don't think there would really be any cost savings. 22awg wires for CAN communication with balance boards is a cheap and simple solution. Wireless is not as simple, and I can't imagine it's as cheap (although I'm not sure).

I need to learn more about it though for sure.