Ok so I have a 12" PBook with a 45watt AC adapter. I have a friend with a 12" iBook and a 45watt adapter, another has a 15" TiPBook and a 65Watt charger. My Kensington car/airplane adapter outputs a continuos 75watts. I am curious as to why they are at different values. As stated in this thread the power adapters can have problems supplying enough charge at a lower wattage and I assume if too high a wattage that the battery and circuitry can be harmed. I would like to know why Apple would use different values and also if I can use a 65watt power adapter instead of the stock 45watt adapter to charge my laptop faster. I think I can as the car charger is at 75 but I want to be sure. Thanks.