We have a couple where I work. I have used it to start the Explorer I drive at work. So far, they have worked just fine. We quit buying the bigger combo power pack/air compressor because after 18 months or so, they won't hold a charge more than a few days. We have not had the new ones long enough to see how long they last. You don't have to worry about jumper cables being charged up, but sometimes a dead vehicle is parked where you can't get to it. We tried to push a lady's car back to jump it, but it would not shift out of park with a dead battery. That's when these things really come in handy. They will also run our MDT and charge up a cell phone. Pretty handy.