[chbot] BMS - How they work?

[Marshland Engineering]

The problem I have (I think) is that you have some sort of regulated charging
circuit. From what I have read, once a cell is at 4.2 v a shunt is activated
to stop further charging. So what happens in the case of a vehicle or bike as
the voltage and current for charging is often much greater than the shunt and
the voltage pack can handle.  How does it stop 'charging' 

If the BMS is set to 4.2 volts, the fully charged batter of 4 cells is 16.8.
Too high for some aftermarket ignitions.