What controls HV battery charging?

Hopefully this is an easy question for someone to answer.

What controls the HV battery fast (DC) charging current and voltage curve? Is it the LBC (BMS) or the VCM? Or something else?

The reason I'm asking, is that my 2015 charges much faster than my 2013 (where current tapers at a much lower voltage). If the LBC controls charging, I will swap a 2015 LBC into my 2013 and re-pair with the car to get a faster charging speed

If it's the vcm, then I can't just swap it out

Note that I am aware that ambient and battery temperature is part of the charge rate calculation, but is a constant in my comparison so is not the cause

TIA

Regardless of which part controls the charging I'd be leery of changing the control algorithm. The charge rates, etc are probably based on the capabilities of the battery. Unless you are sure the 2013 battery is identical to the 2015 battery changing the charging algorithm could cause issues, potentially serious ones.

Indeed. Depending on the build month of the 2013, the '15's pack is either 1 or 2 revisions newer in terms of chemistry.

We have been swapping battery modules, while leaving the original LBC in place, for years. The reported negative affects have been limited to an inaccurate GOM, fuel gauge and turtle indicator

I have personally run one of these "hybrid" packs for years, and have no serious side affects to report

So there are no safety related issues to consider.