Trouble with my drv8825 driver

hey everybody i am in trouble with my stepper motor driver (drv8825) i am using 12 v battery with 2 amp like when my nema17 not connect with my driver the voltage is equal to input voltage 12v but when i connect with my stepper motor the voltage drop to 6v i am very confused like i adjust vref to 0.24v and it consume 0.48 ampere my nema17 starts vibrating but not spin i am using it with my project self balancing robot. Kindly help me guys.

The voltage drop you are describing sounds very strange. What kind of battery are you using, and are you sure it is charged?

If your motor is rated for 2A, then 0.4A per phase may not be enough current to sufficiently power it. Can you try setting your driver’s current limit between 1 and 1.5A, which corresponds to a VREF voltage between 0.5 and 0.75V on the DRV8825?

If charging your battery and adjusting the current limit do not fix the problem, could you post some pictures of your setup and a datasheet for your motor (or a link to where you got it)?

- Patrick