I’ve used and tested several of these power banks over the years. The main difference between different models from different manufacturers seems to come down to battery capacity. The 3400 mAh is on the lower end of the batteries that I’ve tested, which is not necessarily a bad thing. However, it is a bit bulkier than most batteries in this capacity range. What makes this extra bulk more than acceptable in my eyes is its elegant and functional design.

3400 mAh is enough of a capacity to fully charge most smartphones these days. I’ve tested this battery with iPhone 4S and Samsung Galaxy S3 and was able to fully charge both of these devices. The battery has an output current of 1 A, which roughly translates into the slower charging compared to the batteries with 2.1 A. In my experience it takes about an hour to two hours to fully charge a smartphone with this battery, depending on your usage – just like with all the other chargers, you will be able to use your smartphone while charging. I’ve also tested the battery with my iPad, but the charging was too slow and I was only able to get iPad charged to about half of its full capacity.

One of this batteries signature design features is its wrap-around USB cable. This makes it easier to carry your cable with you while on the go, as well as reduces the cable clutter in your bag. Unfortunately, the micro USB charging end of the cable doesn’t work with the iOS devices – for those you will need to use your own USB charging cable. The battery has four green LED lights that indicate the level of charge remaining. Fortunately, those can be turned off so that they don’t disturb you while the battery is being charged in your bedroom at night for instance.

One feature that would make this battery even more useful would be integrated wall outlet charger. That way you would not have to rely on any external chargers or devices for charging. If someone were to design a battery like that, with an integrated i-device support, then that would be a perfect external battery in my eyes.

If you are an Android phone user this small battery will be a great external charger to carry around – it’s portable, effective, and inexpensive.