RAVPower 3350mAh Battery Pack | $5 | Amazon | Promo code KJAPB335
Photo: Amazon

Giant battery packs with capacity for days and three different types of USB ports have their place in the world, but you should also own a pocket-sized pack for quick charges on the go. This one from RAVPower has enough juice for about a full phone charge in most cases, and it’s only $5 today with promo code KJAPB335.