We spend a lot of time researching the gadgets we use, but often gloss over things when it comes to accessories. That seems to be especially true in the case of power, where most of us just sort of use whatever battery or charger we have on hand—convenience is the most important thing. But if you look into the matter, not all batteries are created equal. Thankfully, RAVPower's 27,000mAh, 110V AC-compatible battery has some decent specs in an inexpensive package, and we've got a coupon that makes it even cheaper.