Nintendo's Bill Trinen took time to answer some questions over at Kotaku and there was some very happy confirmation concerning the battery life. I think anyone following 3DS news has heard the "3 - 5 hours" figure that came straight from Nintendo's own Japanese website, but they never clarified what was behind that figure. The 3DS has so many power consuming points to consider; touch-screen use, wireless communications, stereoscopic 3D, microphone use, different brightness levels, and running sound through the speakers or headphones. Well Bill Trinen says that the 3 - 5 hours is definitely with the brightness at it's highest, 3D enabled, and wireless turned on. He confirms that turning off 3D alone could give you as much as 3 more hours of battery life, and (however obvious) that a lower brightness and turning off the wireless functions will also extend the battery life.
It seems so odd how I was just totally indifferent to the very first piece of news about the 3DS (how it would display 3D without glasses, and would be shown at E3), to being blown away by the hardware and games shown around E3, to learning some disappointing news leading up to and including Nintendo World 2011 (such as the very low, but unclear battery life), to being so incredibly hyped up again from the details out of the two January 19th conferences.
I always play my DS lite on the second lowest brightness, and it's very comfortable to my eyes, so I'm sure I will be using a similar level of brightness on the 3DS. I will definitely leave the wireless on unless I'm on a highway or in a very unpopulated area (at my relatives, basically), and the 3D use will depend entirely upon the game. While I understand that it wouldn't be difficult to put a higher capacity battery into the 3DS, I'm very satisfied with an assumed 5 - 8 hour battery life that I will personally get out of the device on average, and the potential to play the device non-stop for an assumed 10 - 15 hours if I want to turn off/down as many battery consuming components as possible. I would say I'm most happy with the idea that there isn't any perceivable reason to wait on a "3DS lite" as they couldn't upgrade or add anything that I would care about (such as phone service), which goes a long way towards justifying my decision to buy the 3DS sooner than later.
What kind of settings do you think you guys will use everyday? Are the benefits of leaving on the wireless promising enough that you would leave it on when you carry the 3DS with you, even if it meant cutting down the battery life of every charge?
I would recommend reading through that Kotaku Q&A as there are some other interesting bits of new info.