For testing we have intentionally stalled the motor, as this can occur out in the field if it is not used properly(jammed board). When the actuator is raising it draws about a maximum of 3A, lowering is obviously less, the current never gets any higher until put into a stall where it reaches above 8A. We have the firmware monitor this current and anything above the 8A we stop the actuator however when stopped the back EMF is sparking across the soldered terminals on the bottom of the relay. This spark is quite visible.
When testing we did put a 0805 100nF 50V cap across the motor terminals to stop the spark and this basically exploded when the stall occurred. Not a great idea.
I am not sure what the stall current of the actuator is will have to do some more testing.
We are running directly off a car/truck battery. The weight of the load is about 20kg so it is not heavy.
Thanks for the replies,
Jason