A bubby of mine bought me one of these for Christmas and swears by it. He uses it on his Porsche that spends a lot of time in the garage and heard me mention jump-starting the GN, again, so figured I could use it. I was just wondering if anyone else has one of these or knows anything about it. I have to admit, I really don't like the idea of leaving a battery charger plugged in and connected to my car all the time. Feels like I'm asking for trouble. Should I worry?