Instead of making devices ultra thin I really wish manufacturers would simply fill up the freed space with batteries Doesn't make much sense. We get the same k

Instead of making devices ultra thin I really wish manufacturers would simply fill up the freed space with batteries Doesn't make much sense. We get the same kind of battery life now that we used to have to carry 2 or 3 spares to achieve, close to 8-10 hours with some models. And it keeps getting better. Even my Air gets around 5 hours of running time, and that too will get better --so no need to compromise on weight for something that can be improved with better technology tomorrow. After a point, it makes no sense to add a larger battery. What use would I have for a 15-20 hour battery? So I can use my laptop in the desert? Not only Apple MacBooks, this goes for mobilephones as well. Samsung Galaxy half an inch thick and a runtime of one week please. Are you going for long stretches of time alone in the woods with your phone? Because even on the road, you can charge it in a car-charger, in a motel, etc. Carrying something heavy and thick is a real problem, because most of us carry our phones 24/7. Charging it every day or every other day, less so. So, I'd go for thin (within reasonable bounds) and light, over thich, heavy but with more battery time.