http://www.nyko.com/products/product-detail/?name=Power+Pak+for+Wii+U

Does anyone have any idea when it will be available? Been waiting for a release date. A day one purchase for me.

3x the longevity? How long do the Nintendo stock batteries last? They're usually good with those sort of things.

I think they last between 3 and 4 hours.

3-4 hours for stock battery. 6-8 hours for the Nintendo upgraded battery (more close to 8 hours I believe). So Nyko will last 9-12 hours or so? I'll probably just get the Nintendo upgraded version considering I usually never buy 3rd party products.

Must remember, bigger battery, more weight, will the Nyko battery bulge out the back? I bought one for my original 3ds and it turned it into a fat little thing, though the feel was nice.

Don't know about weight but I know it fits inside the battery compartment. So no it won't bulge. Can't imagine weight being that big an issues.

Eh, I'll be staying away from Nyko batteries, ever since their rechargeable Wiimote batterys died within a few months if even that.

Also, & I'm not 100% sure, but I keep reading that li-on (nintendo's) batteries are more reliable or longer lasting than li-po (nyko's).

This is probabally true, used the nyko on my 3ds for about a year, and battery was not holding a charge like it used to, switched back to original, it lasts longer than the big fat one did, my son plays it often, my xl never has a problem.

Hopefully they include the upgraded Nintendo battery for future consoles. That would nullify one negative talking point. I don't mind plugging it into the wall but it would be nice to see the original stock battery replaced with new one for future customers. Not sure if Nintendo would see the cost-benefit on that...