This works exactly as it said it would. My car battery was dead. Wouldn鈥檛 even crank when I tried to start the car (I have a push start). Not even the car door locks were working. I hooked this up to my car battery鈥 think my car battery was so discharged that the booster couldn鈥檛 detect it. So I put the bypass mode on, and on one try the car started. This booster is amazing.