Hi Hans,
A folding prop is not ideal for regenerative braking as the blades are obviously supposed to fold back automatically when the boat is moving and the propellor is stopped.
You can try connecting a simple switch to the brake wires and see what happen when the brake switch is turned on while the propellor is still turning fast enough to keep itself open, but I suspect the braking effect of the 10kW motor may slow the propellor too much, allowing the lateral force to overcome the centrifugal force at lower rpm, causing the blades to fold back.
I don't know whether lowering the
Reverse charging current (A) would reduce the braking effect sufficiently to allow the propellor to keep spinning fast enough to stay open with the brake switch activated.
Please note that the VEC500 controller will usually emit a 15 beep error code continually while the brake switch
(regen) is engaged whether the prop is turning or not.
I am pretty sure that the VEC500 controllers do not support variable regen, and the fixed level of regenerative braking
(and cruise function) will only work in the motor's default forward direction, therefore it will not produce any braking effect or charging current if the motor is turning in a "switched" reverse direction.
Alan