I have now used this jump starter to start about 6 cars, my lawn mower 20 times, several motorcycles, work trucks, etc.
This thing is so powerful it managed to start a company work truck that was so dead it couldnt even start by being jump started by a running mazda 3. Clipped this on and it turned the motor over and fired up. The jump starter was beeping at me so I guess i maxed it out but it got the job done. Turns over even completely dead batteries like they were brand new. I can jump several times and the battery level has never gone below 71% even after sitting for months. 5 stars all the way.