I was very impressed with the easy launch of my Niva-Chevrolet, which stood for a week in the cold - 10, - 15 degrees. The battery lives for the 4th winter, it is already rather weak. I used to wear home to warm and recharge. Now I think that up to - 30 this booster will cope with starting the engine without much effort. Haven't tried any other brand of car yet. When I returned home, I checked the booster charge level, 5 bars lit up, 100 percent! Although I reviewed a lot of videos on the Internet about these devices before buying, he impressed me a lot! Very happy with this purchase!