Will be going on a trip to Australia for business. I'm looking for an external battery I can use to power my iPad (1st gen @ 5v, .5 amp), iPod Touch (4th gen), & Asus UX31 ultrabook (19vdc @ +2a) while I'm on that 14hr flight. Unfortunate I won't be in business/1st class where there could have been some chance I would have had access on board power plugs.

TIA!