Motor driver planning
Selecting a motor driver to work with the Lithiumate Lite.
You can get a DC motor driver ("controller") or an AC one ("inverter").
For pack voltages above 40 V, you need a motor driver that is isolated, meaning that the B- input (the negative of the battery pack) is not connected to the ground of the 12 V system.
Otherwise, there is a shock hazard.
Maybe, more than getting shocked, you may mind having a damaged controller.
So, regardless of the pack voltage, get an isolated motor controller.
Ideally, the motor driver must have an enable input, so that the BMS can shut it down it it needs to (to protect the battery).
However, even if there is no such input, there are other, indirect ways that you can wire the BMS to shut down the motor driver (such as by removing 12 V power from it).
Some motor drivers include the ability to regenerate electric energy when braking (inverters for AC motors always do that).
The Lithiumate Lite is compatible with regen.
Ideally, the motor driver must include a control input to disable just regen. That way, if the battery is already full, the BMS can disable the just the regen function, without having to disable the entire motor driver.
Newer, more powerful motor drivers have a CAN bus to enable them to be controller "by wire" instead of dedicated lines.
Most can be used either way. The Azure DMOC is the only one we are aware of that can only be controller by CAN bus.
The Lithiumate Lite does not have a CAN bus (the Lithiumate Pro does).
That doesn't mean that you cannot use a motor driver that has a CAN bus.
The idea here is that the best way to help the driver from getting stranded is to reduce the available drive when any cell voltage starts getting too low.
That will help in the following ways:
You can implement this function in one of 2 ways:
While this function is not required to protect the battery, it is a great convenience to the driver, and we strongly recommend that you implement it.
To implement this function, look for a motor driver that either uses a throttle pot, or has a "valet" control input.
Here is a list of available motor drivers.