Best portable battery?

[PaulWog]

I'm looking to get a large portable battery. Something between 10,000 mah and 30,000 mah, for around or less than $150.

I would prefer the battery to be the form factor of an iPad. I basically want to have something I could stack with a Macbook Pro, or an iPad, and carry around to extend battery life.

If it's cube shaped, or more chunky, that is fine too if that shape makes functional sense. Brand / quality matters as well, since I've had some bad experiences with mobile external batteries in the past just crapping out.

Any recommendations?

 

[carestudio]

I never tried this before but saw the news few months ago
http://www.kanex.com/gopower-usbc

Kanex is not on the top of my Mac accessories list, but they do carry some "OK" stuff.

 

[kayzee]

i dont know much about portable batteries... what exactly does 15,000 mAh mean? do i generally want a higher number?