Batteries are hellishly annoying to change all the time, especially if you don\'t have a charger. Things get expensive when you have to buy new batteries every week just to keep the thing working. My old Trust tablet\'s pen used up it\'s battery in about 4 hours of use, forcing me to buy more. If you\'re an artist, that\'s just won\'t do at all.
Efflixi: The batteryless pens/mice don\'t have cords at all, they simply work when touching the surface of the tablet.