Now retired my trips are about 25 miles total maybe2-3 times a week. Perhaps its a update to increase accuracy (or not...). I would just make enough trips to take the battery down to 10-20%, but since I usually solar charge (trickle), and can charge when there's a fair bit of sun (or partly cloudy), my luck is I'd have to make a longer trip on a low battery. I'm an avid believer of the old saying among pilots..."there are old pilots and bold pilots, but few old/bold pilots".