When the initial three-to-five-hour battery life figure for the 3DS went public, many of us were left wondering what conditions could affect that amount of time. In the new Iwata Asks, 3DS designer Ryuji Umezu and Nintendo president Satoru Iwata give us some much-needed context.
Basically, it's what you'd expect; the 3D and backlighting require a lot of energy. Nintendo has implemented a power save mode which "precisely controls the brightness of the backlight according to the brightness of the screen being displayed," says Umezu. "When the screen as a whole is dark, the backlight itself gets darker, which saves power."
"When I measured [battery life] by playing several Nintendo games, with the backlight set to the brightest level and the power save mode turned off, battery duration was about three hours. But if you use the power save mode under the same conditions, it gets about 10-20% longer. And if you set the backlight to the darkest setting, the battery lasts five hours, but the power save mode makes less of a difference then."
Umezu also explains that the wireless StreetPass functionality doesn't make a huge difference, "but games that communicate a lot through local play and online play -- with the backlight set to high -- have an over 10% effect on the battery."