There are a lot of external batteries/power banks/portable chargers out there, and often the experience can be summarized purely in specs. While there's always odd or unusual behavior to watch out for, you usually know what you're getting when rated outputs, features, and capacities are all listed. The Goal Zero Sherpa 100 AC Portable power Bank checks a whole lot of boxes if you're after a really high-end, airline-safe battery, and right now it's $60 off at multiple retailers, including Amazon, down to just $240 from its usual $300 price tag. The truly monstrous Goal Zero Yeti 1400 is also discounted by $360 to "just" $1,440.