Soundwave on 09 January 2016
It depends entirely on the hardware needs too. If it has a powerful processor and the goal is to push better graphics because they need unification between the portable and console (therefor the portable cannot be weak otherwise you can't have scalable games) and is something along the lines of a Tegra X1 or Apple A9X chip ... absolutely, they'll need something that can power a device at 7-10 watts/hour for 3-4 hours. So that means a large battery.
The good thing though is batteries these days are dirt cheap. The batteries in even high end phones for example cost like $5-$6 at cost.
