rollingrock, your car battery is likely lead-acid or something like that, and its as big as a brick right? and the alternator keeps it charged.. batteries in these mp3 players are a whole other story. Lithium-ion based (expensive), and they have to handle hundreds of complete charge and discharge cycles which is wear and tear to a battery. Oh, and they gotta be really, really small (expensive). The $80 that Gateway may charge is not the price of the battery, either. Probably half of that goes towards the cost of labor to change it out, handling, and profit of course. These batteries probably cost around $40, my best guess as replacement iPod batteries sell to consumers for $50 (see here : www.ipodbattery.com).