I think you're talking about charging directly from a PSU. The discussion is about charging through the controller.
The PSU voltage needs to be well below the battery's discharge voltage. For 14s, you'd be safe with a 24 V PSU. 36 V would be pushing it. 54 V is much too high. Even if you could adjust it down to, say, 48 V, this would not work if your battery were discharged below 48/14 = 3.4 V per cell.
There's really not much more to it than what you've described, and it's unfortunate that more controllers don't implement this. In fact, if a controller does regen, it's basically already doing it. The difference is that in regen the input voltage is the back EMF induced by the motor's motion, whereas in charging the voltage comes from a DC supply. In fact, this is even easier since the controller doesn't have to do commutation switching.ElectricGod wrote: ↑Sep 07 2019 1:03amA lot of people don't know how this works...using a large capacitive bank and an inductor to bump the voltage up to the pack voltage.
I've never used this before, just read about it.
What I understand is the capacitors in the controller and the motor windings are what is used to boost the voltage to pack voltage.
Since you've worked this out, please explain how it works.
In normal operation (i.e. forward motion, forward torque), a controller is basically a variable-output buck converter with commutation thrown in for the motor phases. In regen this is reversed and the controller becomes a boost converter with commutation. In charging mode, it's a boost converter without the need for commutation (the charging is done through only one of the motor phases).
(For the motor control specialists - yes, I know what this controller is doing is better described as SVM rather than commutation - see my avatar! I just don't think it's necessary to go down that rabbit hole to have a general sense of how this works.)