The UNIFUN U821 power bank has been around for quite some time now, but only recently did I have a chance to get my hands on one to see just how good this thing was built and functioned. Although 10,400mAh isn't anything spectacular in terms of backup battery life when compared to the likes of Vinsic's 20,000mAh power bank, it's the rugged construction and waterproof design that makes this option ideal for outdoor use.
Easily portable and able to be pocketed, the UNIFUN power bank measures approximately 5.75 x 2.75 x 1-inches and features a thick plastic casing accented with a TPU bumper around the edge. It feels solid in the hand, weighing about 300g and sporting a metal plate in the center for no particular reason aside from aesthetics. Keeping in mind that it has an IP66 protection rating, it can certainly handle the elements and some nasty drops, but isn't built for submerging underwater for any extended period of time. Included with the power bank is a 2ft. Micro-USB cable that can be used to charge the unit and/or your mobile device.
There are 4 blue LED lights on the front that indicate how much battery life remains: 4 = 75-100%, 3 = 50-75%, 2 = 25-50%, and 1 = 0-25%. Next to the TPU power button on the side is a removable plug that reveals 2 USB outputs and the Micro-USB input. If you're only charging one device you'll want to plug into the 2nd output as it provides a steady 2A charge opposed to the first 1A output. With two devices charging simultaneously there isn't much of a difference in charging speeds, though. Speed isn't so much what UNIFUN is after here as much as a reliable power source that is capable of powering a couple devices in a bind.
Up top you'll find a built-in LED flashlight that's plenty bright enough for navigating your way through the woods or finding personal items in the dark, but I wouldn't rely on it to do much more than that for its size. It can be turned on and off by simply holding the power button for a few seconds. If you're only running the flashlight without charging any of your gadgets on the side you can expect it last around 6-8 days when used fairly regularly. At the opposite end of the power bank is small rubber clip that can be used to attach a lanyard or carabiner for securing to your equipment.
After putting the UNIFUN waterproof power bank through a few cycles I'd say it definitely lives up to the good reviews its been given. The bright orange color makes it easy to spot even in low light situations. It's built well and can take a beating, but I don't know that I'd make this my go-to power bank for every day situations. However, when it's time to hit the water on the weekends or get some hunting in this season I'll definitely tote this one with me.