So stoked for the results!
As I see it, MiniBMS is compatible with just about any charger, so the BMS doesn’t dictate which charger to use. Instead, the choice boils down to the type of electrical outlets or circuits you’ll be using for charging—mainly to avoid blowing fuses.
You’ve mentioned 1000 amps for both the motor and the battery, but in reality, the battery side will rarely, if ever, hit that level. This is especially true with Kelly controllers, which are notorious for inflating their specifications. On top of that, you haven’t clarified your target EV range. The range heavily depends on how hard you’re drawing power from the battery. Higher current draw (C-rate) means shorter trips between charges.
I’m not an authority on motors, but I know that direct drive setups come with significant hurdles. DC motors tend to have a narrow RPM range and can overheat when operating at low speeds. Balancing the gearing to provide enough torque for low-speed performance without exceeding the motor’s RPM at higher speeds is a tough challenge. Direct drive systems also lose efficiency, leading to extra heat in the motor and controller.
When operating at high C-rates, battery cooling can become critical. Cells at the core of the pack often face heat issues since they don’t cool as easily as the outer cells. If ignored, this could lead to premature failure of those central cells.
In all the direct drive projects I’ve seen, there’s almost always some kind of compromise. It might be sluggish acceleration, limited range, reduced top speed, or overheating in the system. Honestly, I’ve yet to see a direct drive conversion that didn’t struggle with one or more of these problems.
