im using 2x2s 5000mah 40c batteries. Ive never actually let the cut-off kick in. It also seems that there are hundreds of opinions on what the safe voltage cut-off is. I wasted my money on the novak smart stop. If i have to time my runs than whats the point of the smart stop or any cut-off for that matter? I guess I need to find a cut-off thats adjustable up to 3.7 volts.