Amazon has the Mpow 12000mAh Backup Battery Portable Charger Power Bank for a low $32.99 shipped. That’s half off the list price and the lowest we could find it for. 60 Amazon customers rated it with a near perfect 4.5/5 stars and left great reviews. The Mpow features dual USB ports that supports two devices charging at the same time including a 2.1A port for quick charging tablets like the iPad. It includes a MicroUSB cable that charges the battery but can then be used for charging devices when away from a AC.
With the money you save on the Mpow, you could get a few GTMax Keyboard Silicone Skin Cover for your Macbook for only $1.65.