This USB Battery Pack Also Has An AC Outlet, and It's Never Been Cheaper
by Shep McAllister on Kinja Deals, shared by Elizabet from Lifehacker on (#4600K)
Portable battery packs with USB ports are a dime-a-dozen, but your options are a lot more limited if you need a portable AC outlet. The Jackery PowerBar though is a great option at a solid price.