This is all very interesting. We are very intermittent users of ours, and have run into battery trouble a few times. I was led to believe the on-board computer was to blame - no-one mentioned that it could be anything so simple as the alarm system. We'll try that and see what happens, but at the same time we won’t want to risk suddenly being without a car when we need it, so I expect we'll go on making a point of giving it a good spin every couple of weeks. <sigh>