I love my Dual Optima's. When I tore off the front end at plant bamboo mudfest on sunday; I cut through the positive wire for my winch on the frame. After the engine fire, I had drained the optima on the winch, but because of the isolator, the other was fine. Even after the engine bay fire, Tonka fired right up, and went home under his own power.
The Optima wasn't even damaged. After a trickle charge, I hooked up the dual system again, and all is well.