This modular BMS uses Bluetooth Low energy to get rid of wires.
This 2 minute footage shows balancing in progress.
Explanations are embedded...
Conclusion: balancers validated...
I managed to finish the assembly of the balancing cards today and I installed them seamlessly on the battery modules. The result is really cool. Performance tests are in progress.
General view of the 10 kWh string:
Each (70-element) module is equipped with a balancing card placed on top of it. This card continuously measures the module voltage and starts to dissipate power whenever the module voltage crosses a certain limit (can be setup up to 4.2 Volts).
A close up on the modules
The first things to notice are the "large" 60 x 60 x 10 mm fans. Thanks to them, each module is capable of a 50 watt continuous power dissipation. The square components with a black on white hexadecimal figure on them are the BlueTooth Low Energy modules (Zentri AMS001). Each BMS card is managed by an NXP LPC824 Cortex M0+ microcontroller featuring a very clean 12 bit ADC, among many other cool things.