I recently got a new 3DS, and have noticed a fair bit of chatter online about the various power saving modes, and how much battery life you should expect.
I have a small device called a Charger Doctor which plugs inline with a USB charger and tells you the voltage supplied and how much current is being drawn, so I decided to investigate if this could be used to test how the various settings make a difference to power usage.
My first assumption was that when the 3DS is fully charged (i.e. the charging light goes out), the device will pull power over the mains lead rather than depleting the battery.
As far as I can tell this holds up as true. I see a drain of less than 1mA when it’s fully charged, but plugged in and off, around 300mA with full brightness, wifi and 3d on, and powersaving off, and around 160mA with brightness at minimum, wifi and 3d off and powersaving on. That equates to roughly 3.5 vs 6.5 hours for max vs min, according to the battery life calculator maths I found online, so it looks roughly correct.
At the bottom of the page you’ll find a link to the Google spreadsheet detailing my tests. These were all performed with the 3DS connected to an Anker Astro E4 battery pack using a USB charge cable. Whenever the battery charging light turned on, I’d wait until it went out again, to ensure the power reading just indicated the actual usage, and not the power being trickled back into the battery.
Overall, I found the following things:
- 3D Off will give you a fair saving in battery life. Just turning the 3D down a bit won’t make a difference.
- Turning off Super Stable 3D doesn’t seem to make any obvious gain.
- Screen brightness makes a huge difference – if you want a long battery life, put it as low as you can!
- The Power Saving option also is worth turning on, if you don’t mind how it makes the screens look.
- Leaving your WiFi on is fine if you’re sat at home with a decent WiFi connection. If you’re out and about, the constant StreetPass scanning will flatten the battery faster, so turn off WiFi if you’re not bothered by the StreetPass hits.
Sleep Mode: As far as I can tell the battery drain is very low – certainly if left at home so it’s not having to constantly scan for new Wifi access points – It should last well over a week left on standby.
3D: Makes a big difference on vs off – Somewhere between 45 minutes and 1.5 hours depending on what you’re doing. Having 3d on but at minimum vs 3d on at maximum makes no noticeable difference, (so turning it “down a bit” won’t save you any power – it’s all or nothing)
Super Stable 3D: Doesn’t actually appear to make any difference in a bright room. It’s possible the camera hardware is always active, even if not being used for head tracking. Actually having a face in view seems to make no difference, either.
Screen Brightness: By far the biggest difference – brightness at minimum should give you at least 1.5 hours extra – possibly much more depending on the game.
Power Saving: Can give you around half an hour extra, so certainly worth leaving it on, if the way it looks doesn’t bother you.
Wifi: When at home, with wifi on, connected to your home router, but not actively doing anything it doesn’t make any obvious difference (so there’s no benefit in turning it off if you’re playing an offline only game.) However, if you’re not at home, it appears to use more considerably power scanning for APs and Streetpass (reducing battery life by anything up to an hour and a half!)
Things I’m yet to test
- Super Stable 3D – in a dark room
- Auto Brightness – again, is it worth it over just manually changing the brightness
- Audio tests – headphones vs speakers
- MH4 – higher drain
Note that all battery life values are just estimates, based on the usage of my European New 3DS – other models will vary.