The Switch seems like a pretty lean so the space for a battery is going to be an issue. The size, and weight, of a battery are a challenge for almost every portable electronic on the market. This lead me to wonder what battery life Nintendo has been using in other devices. Both the 3DS and the Wii U gamepad have 3-5 hours of battery life. This would seem to lineup with the battery life with a lot of smartphones when the screen is on.