What amperage model should I choose for a DC motor driver?
The driver current should be chosen as at least 1.5 times the motor's continuous running current. The instantaneous current at start-up can rise to 3–5 times the continuous current; not leaving this margin shortens the driver's life.
The continuous current value on the motor's nameplate is the starting point, but the selection is not made according to it. At the moment of start-up (inrush) the current rises to 3–5 times the continuous value.
Practical rule: driver current ≥ continuous current × 1.5. In applications with frequent starts and stops or that start under load, take this factor as 2.
It is also important that the driver has instantaneous overcurrent protection; without it, the start-up surge wears out the output stage over time.
The full topic: DC Motor Driver Selection Guide