This is a very convenient and small external battery charger. It’s ideal for the on-the-go situations where you want to be sure that you’ll have extra power on hand in the case your smartphone runs out of power.

The 3000 mAh battery capacity is nominally sufficient to fully charge most smartphones out there. For instance, iPhone 5S battery capacity is little over 1500 mAh, while Galaxy S4 has a 2600 mAh battery. Keep in mind that there is some inefficiency associated with the charging process, so that the amount of power that you get will be about 80%-90% of the nominal battery capacity. I have been able to fully charge my iPhone 4S and Galaxy S3. I’ve also been able to charge my first generation iPad to about 40% of its capacity, but this small battery is definitely not meant to be used with tablets. This is especially true since the 1 A current output will require really long charging period for any of the main tablets out there.

Battery comes with a small USB cable with four different attachments: mini USB, micro USB, Apple 9-pin, and a generic charger. The battery also has a small strap, but I am not exactly sure of what usage situations would it come in handy for. This is an ideal battery to carry around with you in your pocket.

Both the instruction booklet and the info on the box are written in very bad English, and phrases vary from incomprehensible to hilarious. There are no mentions on the box’s cover of the battery’s capacity or charging times, things that are among the most useful pieces of info for comparison shopping for instance.

Even though this power bank works well enough, and it seems adequate for most purposes for which it’s intended, its design and build quality don’t exactly scream high quality and elegance. The exterior shell is built out of two pieces of plastic that were snapped together, and the joining edge is a bit sharp and unrefined. I am not a total design snob, but the build quality of this battery makes me wonder how durable it is in the long run. I would have also appreciated some way of gauging the total charge capacity. As it is it’s impossible to tell how much charge you have left before the battery discharges completely.

I also think that at $15 this battery is reasonably priced. It doesn’t have all the bells and whistles of the some of the more sophisticated batteries that are available out there, but so far it has gotten the job done just as advertised.