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 50% of its capacity, but this small battery is definitely not meant to be used with tablets. The battery uses 5V/1A for both the input and the output, which is the typical voltage/current for most smartphone chargers.

This battery has a very basic cylindrical look. Most of the body is made out of an aluminum pipe. The pipe actually screws in at one end, so you can open up this battery and take a look at its innards. Those are not particularly pretty to look at: a big cylindrical battery taped to a small logic/USB board. The battery has a small LED light at one end that glows when the battery is being charged or discharged. The whole battery looks like a big roll of Mentos. The other end of the battery has a small LED flashlight. This form factor is actually ideally suited for such function, but unfortunately the lightbulb is not very bright. If the manufacturer were to increase the lumens in the future version of this product then this could really be a very convenient multipurpose tool.

The battery comes with a 2-in-one USB cable that has both the micro USB and the Apple 30-pin ends. This is one of the few such batteries that includes the Apple cable, but it’s probably not Apple-certified. The cable worked fine with my iPhone 4S and first generation iPad, but as Apple phases out the 30-pin cable in favor of the lightning cable this charger’s cable will become obsolete.

At $15 this battery is pretty reasonably priced. I am not sure how reliable it is in the long run, but so far I’ve had pretty good experience with it. 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.