It depends on the battery and motor voltage.
If they are all 12v or 24v wire them in parallel.
If you have 2 xx 12v batteries, you can wire the batteries in series to give 24v into the controller.
If your motors are 12v, wire the 2 on each bogie in series and then the wires from each bogie in parallel.
Make sure you set the link in the controller to the correct battery voltage.
Stuart
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