wait! now it's a good thing that this abomination needs its own battery?

You still have to physically replace it. I don't get why since the 3DS has its own power.

Probably because it'll be plugged into the battery entrance, and this is able to absorb power, not to release it. Still the opposite was possible: another battery for the add-on, which would eventually be used by the console itself.

There WILL be a third party version with a built in battery that extends the 3DS's life. I'm sure of it. Just wait and see. Probably won't be six months after the real deal comes out.....

I believe the Slide Pad communicates with the 3DS thru the infrared port, thus the need of an AAA battery.
Hopefully 480 hours will be enough to keep the thing working until the redesigned 3DS is released (with the 2nd slide pad built-in). This way a battery replacement wouldn't be necessary (unless you want to keep the thing in your collection, on which case I would recommed you remove the battery before storing it).

LOL! I wish that was true, you'd only have to it like 20 times a year!

I'm not going to lie when I looked at the title, at first I thought it said the slider pad extended playtime 480hours as in the 3ds lasts 480hours...

lol I misunderstood the title at first

I still don't get why the thing doesn't work off of the 3DS battery life -_-