Reliable, safety-certified portable power for any smartphone or tablet Reliable, safety-tested and certified portable power where and when you need it. Reserve Power Banks deliver safe, dependable power for phones, tablets, GPS units, wearable and most other devices that charge via USB. Charge On The Go - UL-tested and certified Li-Ion batteries recharge from any wall charger, car charger or laptop/PC. Then connect your Lightning cable – or the micro-USB cable that ships with each Reserve Power Bank – to recharge your devices. The standard USB port delivers 12 watts of charging power (5 volts at 2.4 amps) for fast, safe charging. LED power gauge shows the battery's charge capacity with the push of a button. Slides easily into any pocket, purse, back or backpack so you're never without power. More Power to You – How far will 9000 mAh take you? Smartphone - Up to 3.6 charges Smartwatch - Up to 27.5 charges Large Tablet - Up to 1.2 extra charges That's enough to keep you powered up wherever your day takes you*. Built & Tested for Long, Reliable Life – Reserve Power Banks' safety-certified Li-Ion cells are secured inside a drop-tested, durable polycarbonate shell. Built-in power management circuits prevent the battery from overcharging, and from charging the attached device at a rate faster than it can safely handle.