I thought I would give one of these a try, I was a skeptic but now I am not, I jump started my 77 suburban with a 350 and a stone cold dead batt. I had to try about 15 times to get it to start(cranked 3 sec and let set 10) no gas to the carb, it had been sitting for about a month. But it did start. I should have primed the carb but I wanted to see what this thing could do. I got it for my dr650 just cause it makes me nervous with no kick starter and it is a heavy bike to push start I also use it for usb charging like my phone and little quadcopters.