Ive checked the circuit again and all I can say is if you think its got polarity protection then try it. The MOSFET are not protected (acording to there published circuit) and will generate a short across the battery. The only protection they have is before the voltage reg for the ICs. This should be made clear or someone will try it and be very dissapointed. If it does have a diode protecting it as it says it does then a diode at 100A with a 0.7V (at best) will produce 70W of heat!! Far more than you will get with just the MOSFETS and would take this power away from your motor. Again all I can say is try it but be prepared for the cost of repair.