Three to five hours of battery life to be specific. That’s pretty wimpy compared to the amount of time a regular DS can hold up(close to 15 hours). I expect this is because of 3D demands of the new handheld. Cool graphics cost you some hefty battery life. As for recharging your system, that will take 3.5 hours.
This is not a deal breaker but it is a little annoying. I could go quite a bit of time without charging my DS but then again I don’t play it regularly. I guess the 3DS will not be made for those long plane rides.