Never had a problem with mine.......... until a week ago. I was off skiing for a week and when I returned, the battery was flat. I jumped it from my wifes car and all has been well since. It was also v cold while I was away (-10 C) which I think had a part to play. My suggestion would be to buy a battery conditioner and leave it connected while you are not using the car. They are pretty cheap and I guess the cable would shut in the boot lid quite easily.