The RAVPower 14000 mAh PB-13 is powered with a Samsung Lithium-Ion battery. The power bank is charged via a micro-USB port on the side. It is rated at 100-240V. 2-USB to USB-micro cables is provided. Multiple adapters for various devices and a travel mesh bag. It even has a LED flashlight, which is operated by a 3-second press of the power button.
The design is simple and the battery is very simple to use. I have a white one, they have black also. 4-blue LED's provide an indication of the battery status of the Power Bank. It has over current and short circuit protections built in. Charging is really easy. It has a superfast output charge. Dual USB ports provide a 1A and 2A availability. So, yes you can charge 2 devices at once. The 2A plug will drive a lot more power to your phone.
I use this mainly to charge either my laptop or Galaxy Note 3. I can start with a full charge on my RAVPower 14000 mAh with a dead phone and get almost 3 full charges. On my laptop I have never really used it for more than a boost. What I do notice is I can use my laptop steadily for about an hour and battery life remains stable. If I just use it for a quick boost while leaving the laptop idle I see it increase at about 10% every 20 minutes or so.
In conclusion, all I can say is this is my go to of all the chargers I have. It has never failed me and I use it almost daily. If you need a boost in your charging life, then this is for you.
You can grab one HERE
1-light = <25% charge.
2-lights = 25-50% charge
3-lights = 50-75% charge
4-lights = 75-100% charge
Output: 5V / 1A; 5V / 2A
Input: 5V / 1A
Weight: 10.6 ounces
Size: 4.92 x 3.15 x 0.79 inches