What I was trying to say in comparing the two approaches is that with the diode, the motor will continue to supply torque because the diode is allowing current to continue to flow in the motor.
However with the MOV, there is not path for the motor (now functioning as a generator) to maintain current in the motor.
It sounds like the spool down time is not critical. In that case you should go with whatever makes you most comfortable, which sounds like the diode. Just remember the MOV if the diode doesn't work our (i.e. too much power to dissipate.
Relentless searching has led to perhaps a slightly better choice of diode, although now I am getting feedback from members that has me thinking twice about needing one at all:
My only worry would be, if this thing ever shorts out, it will provide a direct path to the battery which could set fire to the whole electrical circuit... and my car.
You use the right fuse to prevent that. A diode that takes 200A at 100V will explode immediately anyway.
You should realise its essential to wear eye-protection working on high-current circuits due to
such failure modes? Shorting out metal contacts at those power levels also splatters metal vapor and
molten metal around, another reason to wear eye-protection (and gloves). And don't forget the
high voltage(!)
200A fuse? I didn't know they went that high. I figured it was all breakers at that point. In any case I recently purchased a "battery disconnect rotary switch" rated at 300A. I will use it to open the circuit when I leave the vehicle (frequently) or in an emergency short condition (hopefully seldom).
Gahhhrrrlic:
200A fuse? I didn't know they went that high. I figured it was all breakers at that point. In any case I recently purchased a "battery disconnect rotary switch" rated at 300A. I will use it to open the circuit when I leave the vehicle (frequently) or in an emergency short condition (hopefully seldom).
High power dc fuses are specialist - breaking a high power DC arc is not trivial, so a breaker/contactor might be
the best option - you'd have to research this.