SC430 auto 2005: Advice re flat battery. I've had my beautiful car for nearly 6 yrs and it has been reliably unreliable during this period in not starting if I leave it for any period of time. During the winter I can drive 100 miles, park for a couple of hours, then it won't start without being jumped. In the summer I can sometimes leave it for a couple of days before it fails to start. Again I have to jump start it. Despite renewing the battery annually and making sure I turn EVERYTHING off, I now permanently carry a very heavy duty power pack in the boot to start up wherever I am. It's a joke. On one occasion I drove it for most of the day, stopped to concentrate on a hands free call for 20 minutes only to find I had to jump it to re-start. My local dealer has not been able to resolve and I really don't know where to turn to. I absolutely love my car but I no longer drive it in the winter, too much trouble in the rain to jump it, so it is garaged for at least six months. I've read that other owners have had the same or similar problems - if they've been resolved, how? Certainly doesn't look good for Lexus, my local fiends/neighbours can't understand it at all. Find it amazing that I haven't got rid by now!! We've tried a trickle charge but even that can't be relied upon on such a big engine. Any advice. I live in Hampshire.