So come into this thread I read the OP, see the 3 hours charge time, think "that's pretty reasonable", and see that they're using a 4310 mAh battery, which is on the top end of what I would have expected. Good stuff.
And then I start reading the replies... holy hell. I know neogaf has a reputation for over-reacting to things, but this thread is just straight up nuts. Go outside, take a walk, have a breath of fresh air, and when you've calmed down you can come back and we can actually look at the facts.
You're back? Great, nice day outside, isn't it? Okay, now let's talk batteries.
Battery Size
At 4310 mAh, Switch has
by far the highest-capacity battery of any gaming device ever made. Here's what's currently out there:
3DS / 2DS - 1300 mAh
New 3DS - 1400 mAh
(New) 3DS XL - 1750 mAh
PS Vita - 2200 mAh
That's about twice the capacity of PS Vita or almost three and a half times the capacity of the 3DS or 2DS.
Now, you're surely saying "but X phone or Y tablet has such-and-such a capacity, Nintendo must be able to fit more in there!", but I'm willing to be X phone and Y tablet aren't actively cooled. A typical phone or tablet these days is basically a battery with some electronics and a screen attached. For a phone the battery could account for 60-70% of the internal volume, and it can be even higher for tablets.
Nintendo doesn't have the luxury of dedicating so much internal space to batteries, because it has to fit a fan and heatsink in there, which likely occupies as much as half the space between the screen and the rear of the case. Have a look at this rear-view photo of the Switch:
The blue box I've included is pretty much the best-case-scenario for how much space Nintendo can allocate to the battery in Switch. If you look at the fan vents at the top and bottom of the unit you can see where the heatsink and fan are going to sit (and I've been pretty conservative with the red box for this, as I'm not even including the area around the third vent to the lower right). Then on the left we've got space taken up by the game card slot, microSD slot, kickstand, and likely part of the logic board (which will overlap the cooling system).
There's no space for a bigger battery. The reason I say 4310 mAh is at the top end of what I would have expected is because there's just nowhere to put anything bigger. A 4310 mAh battery is basically Nintendo squeezing as big a battery as they possibly can in there. Quote me on this, when we see teardowns in March there isn't going to be some big gap where they could have put a bigger battery. They've squeezed in as much as they can without increasing the physical size of the device.