I’ve been testing a bunch of different external USB batteries lately and will be posting a review of them soon, but this one caught my eye as something a bit different and worth its own review. It’s the Unifun 10400mAh USB External Travel Battery.
The thing that makes this one different from most of the others is that it’s ruggedized. In other words, it’s designed to withstand shocks and bumps, water, and dirt and dust that come with the territory of many of the places you want to use your devices. That’s something that’s likely to appeal to many GoPro users, especially those that use their cameras in precisely the kinds of situations where water and getting knocked around might be an issue. But there’s no reason it shouldn’t work with any device that uses the USB charging standards of 1A or 2.1A. I’ve used it with an iPhone and camera battery chargers.
The battery is completely encased in a bright orange plastic shell. The gray strips around the edges and on each face are softer rubber that help absorb light bumps and provide some grip when it’s lying down.
There’s also a flashlight. I don’t really get why battery manufacturers have decided that a flashlight is a must-have feature of external batteries, but several of them have it. The light it puts out is okay, but it’s nowhere as good as a dedicated flashlight. You turn it on by holding the power button down for a few seconds. It’s nominally a 3.3v/1W LED, but in practice that translates to a fairly dim light that can nevertheless still be useful in many circumstances like rummaging around in a backpack or finding something in a tent.
There are two regular USB output ports and a micro-USB input for charging the battery itself. You access the ports by pulling out a plastic cover that provides a basic seal against water.
There’s one button–a power button–and the charge status is indicated by four blue LED lights on the top.
It comes with a micro-USB cable. It doesn’t come with an AC plug, so you’ll need to have something else between the wall outlet and the micro-USB cable like an AC USB plug, a USB multi-port charger, or a USB car charger. There’s also a built-in loop for attaching to a keyring or clip (but it doesn’t come with the wrist-strap pictured here).
The battery is rated for a capacity of 10400mAh but, like many of the cheaper batteries from smaller brands, that’s exaggerated, and you’re not going to get anywhere near that in real-world use. There are combinations of reasons that can be–the manufacturers use cheaper, lower-capacity batteries to cut costs, and the process of moving power from the external battery, through a cable, and then into the battery of your device is quite inefficient.
I tested with a GoPro HERO4 Black (which uses exactly the same battery as the Silver and is rated for 1160mAh), charging with the battery inside the camera and running it down completely each cycle to the point that the GoPro wouldn’t power on. I was able to fully recharge the GoPro almost 6 times. So if you multiple that out, it comes to a little under 7000mAh. But your mileage will vary according to several factors, including what kind of device and charger you’re using and even temperature (lithium batteries don’t like the cold).
Although they’re not clearly marked as such, the two USB outputs aren’t equal. Output1 (closest to the end) puts out 5V/1A, which is the most commonly used output and is used by many phones and things like GoPro cameras. Output2 (closest to the middle) puts out a maximum of 5V/2.1A, which is often used by larger smartphones and tablets. But if you’re using both at once, the maximum combined output you can get is 2.1A, not 3.1A as you might expect. If a device can only handle 1A but you plug it into the 2.1A slot, the battery’s circuitry registers that and will only output 1A. Once your devices stop drawing charge the battery turns off after 30 seconds.
It is shock-resistant, dust-resistant, and water resistant, but only up to a point. It shouldn’t be confused with waterproof–you don’t want to be submerging this. The seal on the cover over the ports isn’t designed to withstand water pressure or a dunking. Technically, it has an IP66 rating, which means it should be completely protected against dust and protects against being sprayed with water (but not immersion). In practice, it’s only as good as the seal over the ports, so you have to make sure that the cover is securely in place.
The model number is U821.
It weighs 10.6oz / 300g.
It measures 5.8 x 3 x 1.1 inches / 147.5 x 75.5 x 28.5 mm.
The internal batteries are 18650 lithium battery cells rated for 1000 charge and discharge cycles.
For a sub-$20 battery, while the battery performance doesn’t live up to the best in class, the Unifun 10400mAh USB External Travel Battery does have features that most other batteries don’t and that make it attractive as an option for taking outdoors. So long as you’re realistic about how much juice it holds and aren’t immersing it underwater, it works well.
I bought mine at Amazon.