I saw some reviews of this 14,000mAh pack from RAVPower on Youtube. I want to buy something like this but I am not sure if this is the right one for my Samsumg Galaxy4. Do you guys have some experience in picking this kind of product? I checked in Amazon and found the price is acceptable and is the quality I am worry about..

http://]http://www.amazon.com/RAVPow...dp/B00EHEEFWY/

Any advice on this would be really appreciated. thanks.