I just realized. The Switch on the go needs, at least, three batteries, one for the screen and two for the controllers when dettached. How energy consuming is that going to be? How will the battery life of each individual device be?

I hope its at min, 8 hours

One of the biggest variables about it right now (along with price). My best guess is a new tegra chip with an equal balance of power and efficiency upgrades over the X1, giving maybe 6 hours of play on a charge.

Probably 5 hours. 6 if we're lucky

Probably around 3-4 hours

I'm guessing 4-5 hours for the most demanding games. It's already a powerhouse, but being actively cooled, the fan is going to use extra power whenever it needs to run. We can only hope it has a user replaceable battery, or that the tablet can siphon power from the controllers' batteries if it needs to. 6 hrs would be incredible, considering that's what I get while just web browsing on my phone and tablet.

On the plus side, it's pretty thick, so they may have put a pretty beefy battery in there to begin with. Only time will tell.

It needs 6-8 hours. Hopefully NVIDIA pulls this off.

If the Wii U Pro can last 80 hours, the Joy-cons should handle infinite battery.

It's as big as a Shield tablet, so I would use that as a baseline. I would guesstimate 5 to 6 hours. It used more power than a Vita/3DS, but the batteries on these two are way smaller than on tablets.

5-6 hours would be amazing since my rotten mobile phone (Samsung S4 mini) doesn't even last two hours in games.

I think 3-4 hours is the sweet spot and anything over that is a huge bonus and engineering masterpiece.