Thought these would be a great product since they had great reviews. Bought them last year, so couldn't return them now. This last week we left the headlights on overnight while camping and needed to use these (getting a jump from a fellow-camper's big dually truck). At one point, a trickle of electricity came through, but not enough to ever start the ignition. Finally had to call roadside service who jumped my car in seconds, once they attached their cables. It wouldn't have been so bad had I known these were faulty ahead of time, but considering the hours spent delayed on our trip, plus the inconvenience of dealing with the roadside service company, were a disappointment. Now I'm throwing them out and buying some high-quality cables. I won't ever buy anything from amazon brand again that I need to absolutely rely on.