Nyko has announced some accessories for the upcoming American launch of the Nintendo 3DS, which should help the device’s battery life. The Power Pak+ plugs into the 3DS and will deliver about double the battery life. It adds extra bulk, but has a debossed surface to improve your grip.

You can also opt for the Charge Base, which powers up the 3DS directly and comes with a Power Pak+ of its own to extend battery life. Both can use the official 3DS AC adapter for a recharge. The Power Pak+ should be available on March 27 for $20. The Charge Base will be ready soon after and should cost $30.

The Samsung Galaxy S handset already has a user-replaceable battery. The kind you don’t even have to unscrew some screws to get at even. Just open the back cover and swap it out for a fresh one. It’s designed to be that easy.

So we aren’t sure why you would want to bulk up your phone with this thing, even if it does give you an extra 8.5 hours of talk time. Still, we’ve seen worse. Nothing on pricing or availability yet.

A common complaint about the iPhone and the iPhone 3g is that it runs out of juice more often than we’d like. PhoneSuit may just have the solution with it’s new Mili Power Pack. It slides onto your iPhone/iPhone 3G from the bottom, covering most of the back of the device while leaving both the top and the front exposed.

The Mili features an 1800 mAh battery and a mini-USB port for recharging, while a full-size USB port can be used for charging other accessories. According to PhoneSuit, the Mili Power Pack will give you up to 350 hours of standby time, 6 hours of talk time or Internet use over 3G, 12 hours of talk time on EDGE, and 7 hours of Internet use over Wi-Fi. Also 28 hours of audio playback or 8 hours of video playback.