REI offers the Goal Zero Yeti 150 Portable Power Generator for $183.49 with free shipping. (Amazon charges the same.) That's the lowest price we could find by $47, although we saw this for $3 less last November. Meant for powering laptops, smartphones, and other smaller devices, this generator can be charged via wall outlets, solar panel (not included), or a 12-volt AC adapter (also not included).