Motor configuration reference

Default values and descriptions for all motor configuration limits in VESC firmware — current, voltage, temperature, speed, and more.

All default motor configuration values are defined in motor/mcconf_default.h. Every value can be overridden per hardware target via #define in the hardware header before including mcconf_default.h.

Current limits

Current limits protect the motor and controller from damage. The firmware enforces these limits continuously.

Parameter	Default	Description
MCCONF_L_CURRENT_MAX	60.0 A	Maximum motor current (motoring)
MCCONF_L_CURRENT_MIN	-60.0 A	Maximum motor current (braking / regeneration)
MCCONF_L_IN_CURRENT_MAX	99.0 A	Maximum battery/input current (discharge)
MCCONF_L_IN_CURRENT_MIN	-60.0 A	Maximum battery/input current (charge / regen)
MCCONF_L_MAX_ABS_CURRENT	130.0 A	Absolute instantaneous current above which FAULT_CODE_ABS_OVER_CURRENT is triggered
MCCONF_L_CURRENT_MAX_SCALE	1.0	Scale factor applied to MCCONF_L_CURRENT_MAX
MCCONF_L_CURRENT_MIN_SCALE	1.0	Scale factor applied to MCCONF_L_CURRENT_MIN

Input current mapping

Parameter	Default	Description
MCCONF_L_IN_CURRENT_MAP_START	1.0 A	Input current at which the q-axis current limit mapping begins
MCCONF_L_IN_CURRENT_MAP_FILTER	0.005	Low-pass filter constant for the mapped input current limit

The absolute current limit (MCCONF_L_MAX_ABS_CURRENT) applies to the unfiltered peak current. If MCCONF_L_SLOW_ABS_OVERCURRENT is true (default: false), the filtered current is used instead, which is slower to react.

Voltage limits

Parameter	Default	Description
MCCONF_L_MIN_VOLTAGE	8.0 V	Minimum input voltage; triggers FAULT_CODE_UNDER_VOLTAGE below this
MCCONF_L_MAX_VOLTAGE	57.0 V	Maximum input voltage; triggers FAULT_CODE_OVER_VOLTAGE above this

Battery cutoff

As battery voltage drops, the firmware gradually reduces positive current to protect the battery:

Parameter	Default	Description
MCCONF_L_BATTERY_CUT_START	10.0 V	Start reducing positive current output at this voltage
MCCONF_L_BATTERY_CUT_END	8.0 V	Positive current is fully blocked at or below this voltage
MCCONF_L_BATTERY_REGEN_CUT_START	1000.0 V	Start reducing regenerative current at this voltage (effectively disabled by default)
MCCONF_L_BATTERY_REGEN_CUT_END	1100.0 V	Regenerative current is fully blocked above this voltage (effectively disabled by default)

The regenerative cut defaults are intentionally set far above any realistic battery voltage, meaning regenerative braking is not voltage-limited by default. Set these to meaningful values (e.g., 4.1 V × cells) to protect lithium cells from overcharge during braking.

Temperature limits

The firmware monitors both MOSFET (FET) and motor temperatures. When temperature exceeds the start threshold, current is linearly reduced. At the end threshold, the output is shut off entirely.

MOSFET temperature

Parameter	Default	Description
MCCONF_L_LIM_TEMP_FET_START	85.0 °C	Begin current limiting at this FET temperature
MCCONF_L_LIM_TEMP_FET_END	100.0 °C	Shut off all output at this FET temperature; triggers FAULT_CODE_OVER_TEMP_FET

Motor temperature

Parameter	Default	Description
MCCONF_L_LIM_TEMP_MOTOR_START	85.0 °C	Begin current limiting at this motor temperature
MCCONF_L_LIM_TEMP_MOTOR_END	100.0 °C	Shut off all output at this motor temperature; triggers FAULT_CODE_OVER_TEMP_MOTOR

Acceleration thermal derating

Parameter	Default	Description
MCCONF_L_LIM_TEMP_ACCEL_DEC	0.15	Decrease temperature thresholds by this fraction during acceleration to provide extra headroom

Motor temperature sensor

Parameter	Default	Description
MCCONF_M_MOTOR_TEMP_SENS_TYPE	TEMP_SENSOR_NTC_10K_25C	Motor temperature sensor type
MCCONF_M_NTC_MOTOR_BETA	3380.0	Beta coefficient for NTC thermistor
MCCONF_M_PTC_MOTOR_COEFF	0.61 %/K	Temperature coefficient for PTC sensors
MCCONF_M_NTCX_PTCX_RES	10000 Ω	Reference resistance for custom NTC/PTC sensors
MCCONF_M_NTCX_PTCX_BASE_TEMP	25.0 °C	Reference temperature for custom NTC/PTC sensors

Supported sensor types (temp_sensor_type):

typedef enum {
    TEMP_SENSOR_NTC_10K_25C = 0,
    TEMP_SENSOR_PTC_1K_100C,
    TEMP_SENSOR_KTY83_122,
    TEMP_SENSOR_NTC_100K_25C,
    TEMP_SENSOR_KTY84_130,
    TEMP_SENSOR_NTCX,
    TEMP_SENSOR_PTCX,
    TEMP_SENSOR_PT1000,
    TEMP_SENSOR_DISABLED
} temp_sensor_type;

Speed limits

Parameter	Default	Description
MCCONF_L_RPM_MAX	100000 ERPM	Maximum electrical RPM (upper)
MCCONF_L_RPM_MIN	-100000 ERPM	Maximum electrical RPM (lower)
MCCONF_L_RPM_START	0.8	Fraction of maximum RPM at which RPM-based current limiting begins

Duty cycle limits

Parameter	Default	Description
MCCONF_L_MIN_DUTY	0.005	Minimum duty cycle (avoids discontinuous conduction)
MCCONF_L_MAX_DUTY	0.95	Maximum duty cycle
MCCONF_L_DUTY_START	1.0	Duty cycle fraction at which current limiting is applied (1.0 = disabled)

Brake limits

Parameter	Default	Description
MCCONF_L_CURR_MAX_RPM_FBRAKE	300 ERPM	Maximum ERPM at which full brake (all-low-side) is applied
MCCONF_L_CURR_MAX_RPM_FBRAKE_CC	1500 ERPM	Maximum ERPM at which full brake is applied in current control mode

Power limits

Parameter	Default	Description
MCCONF_L_WATT_MAX	1500000 W	Maximum output power
MCCONF_L_WATT_MIN	-1500000 W	Maximum braking power (negative = regen)

The default power limits are set to very high values (1.5 MW) and are effectively unlimited for all practical VESC hardware. Set these to realistic values to prevent battery over-discharge or motor overheating.

Speed PID parameters

Parameter	Default	Description
MCCONF_S_PID_KP	0.004	Proportional gain
MCCONF_S_PID_KI	0.004	Integral gain
MCCONF_S_PID_KD	0.0001	Derivative gain
MCCONF_S_PID_KD_FILTER	0.2	Derivative term low-pass filter coefficient
MCCONF_S_PID_MIN_RPM	900.0 ERPM	Minimum RPM setpoint in speed control mode
MCCONF_S_PID_ALLOW_BRAKING	true	Allow the speed PID to apply braking current
MCCONF_S_PID_RAMP_ERPMS_S	25000 ERPM/s	Input speed ramp rate
MCCONF_SP_PID_LOOP_RATE	PID_RATE_1000_HZ	PID loop execution rate

Position PID parameters

Parameter	Default	Description
MCCONF_P_PID_KP	0.025	Proportional gain
MCCONF_P_PID_KI	0.0	Integral gain
MCCONF_P_PID_KD	0.00000	Derivative gain
MCCONF_P_PID_KD_PROC	0.00035	Derivative gain applied to the process variable
MCCONF_P_PID_KD_FILTER	0.2	Derivative term low-pass filter coefficient
MCCONF_P_PID_ANG_DIV	1.0	Divide the angle by this factor before the PID input
MCCONF_P_PID_GAIN_DEC_ANGLE	0.0	Reduce PID gains when the error is below this angle (degrees)
MCCONF_P_PID_OFFSET	0.0	Angle offset applied to the position setpoint

Ramping

Parameter	Default	Description
MCCONF_M_RAMP_STEP	0.02	Maximum duty cycle ramp step per millisecond at full duty cycle
MCCONF_M_CURRENT_BACKOFF_GAIN	0.5	Error gain for the current limiting backoff algorithm

Fault behavior

Parameter	Default	Description
MCCONF_M_FAULT_STOP_TIME	500 ms	Duration during which commands are ignored after a fault
MCCONF_L_SLOW_ABS_OVERCURRENT	false	Use the filtered current for absolute overcurrent detection

Encoder configuration

Parameter	Default	Description
MCCONF_M_ENCODER_COUNTS	8192	Encoder counts per revolution
MCCONF_M_ENCODER_SIN_AMP	1.0	Sin/cos encoder sine channel amplitude
MCCONF_M_ENCODER_SIN_OFFSET	1.65 V	Sin/cos encoder sine channel offset
MCCONF_M_ENCODER_COS_AMP	1.0	Sin/cos encoder cosine channel amplitude
MCCONF_M_ENCODER_COS_OFFSET	1.65 V	Sin/cos encoder cosine channel offset
MCCONF_M_ENCODER_SINCOS_FILTER	0.5	Signal filter constant for sin/cos encoder
MCCONF_M_ENCODER_SINCOS_PHASE	0.0°	Phase correction for sin/cos encoder
MCCONF_M_SENSOR_PORT_MODE	SENSOR_PORT_MODE_HALL	Mode of the hall/encoder port

Setup info

Setup parameters are used to convert electrical measurements (ERPM, amp-hours) to mechanical units (m/s, km):

Parameter	Default	Description
MCCONF_SI_MOTOR_POLES	14	Number of motor poles (electrical cycles per mechanical revolution × 2)
MCCONF_SI_GEAR_RATIO	3	Drive gear ratio (motor revs per wheel rev)
MCCONF_SI_WHEEL_DIAMETER	0.083 m	Wheel or drum diameter
MCCONF_SI_BATTERY_TYPE	BATTERY_TYPE_LIION_3_0__4_2	Battery chemistry
MCCONF_SI_BATTERY_CELLS	3	Number of cells in series
MCCONF_SI_BATTERY_AH	6.0 Ah	Battery capacity
MCCONF_SI_MOTOR_NL_CURRENT	1.0 A	Motor no-load current (used in efficiency calculations)

Miscellaneous

Parameter	Default	Description
MCCONF_M_INVERT_DIRECTION	false	Invert the motor direction
MCCONF_M_DRV8301_OC_MODE	DRV8301_OC_LIMIT	DRV8301 over-current protection mode
MCCONF_M_DRV8301_OC_ADJ	16	DRV8301 over-current threshold adjustment
MCCONF_M_HALL_EXTRA_SAMPLES	3	Extra ADC samples for hall sensor filtering
MCCONF_M_BATT_FILTER_CONST	45	Battery voltage level filter time constant
MCCONF_M_OUT_AUX_MODE	OUT_AUX_MODE_OFF	Auxiliary output mode

Changing current limits, voltage limits, or temperature limits outside the rated range of your hardware can cause permanent damage to the MOSFET bridge, motor, or battery. Always verify your hardware’s ratings before adjusting defaults.