I've always wondered why companies making computing devices that run off batteries continually made things smaller and smaller, with the goal of also keeping the same (poor) battery life, rather than realizing that after a certain point these devices are small enough and they should instead start cramming ever bigger batteries into the same form factor.
Take an iPhone 4 and 5 as a recent example. The size of an iPhone 4 is just fine. I wouldn't want something smaller, in fact. Yet, with the iPhone 5 they had as one of their goals the idea to make the thing thinner in order to make it smaller. And while they made the power usage of the device better than the older device, they also made the battery smaller, relatively speaking. So in the end, the battery life isn't dramatically better than before. It is merely about the same, while you do get better performance from the device than you do the older one. I'd much rather have a device that was still the same thickness as before, with all the components inside still having undergone the size reduction they did, and with all the same power usage advances, but a much larger battery taking up all the saved space. This would give you a much better usable battery life. The device was already small enough. Making it smaller wasn't much of a gain.
Laptops have been the same story ever since there were laptops. It would be nicer if they lasted longer while running on the battery. They were pretty bulky in the beginning, but after a few years they got to a certain size that was most certainly small enough. And as time marched on, everything inside them got smaller and smaller, and we got smaller and smaller machines. And power usage for them kept getting better and better, but they kept putting smaller and smaller batteries in them as the overall device got smaller, too. And so, battery life was never improving. It was still being built to a certain battery life goal, which is all well and good, unless that goal is too short.
By this time, with all the power usage improvements that we've seen, and battery design improvements that we've seen, we should have had laptops that lasted 24-48 hours on a single charge many years ago. This story about Sony's device getting 24 hours of usable life out of a charge, with an external add-on battery for crying out loud, shouldn't be something to salivate over. This should've been the norm many years ago. With a battery inside the thing that is already capable of such usable life per charge. After a certain point, small is small enough, and we should be putting that space to use for more usable life out of those suckers.