Mobile battery packs can power your USB devices on the go, but they often come with ports that offer different amounts of power. Poor labelling can sometimes add to the confusion, so here's what you need to know to ensure you use the right port for your device.
If you're lucky, your battery will just list the amount of power each port provides in amps (like the first one shown in the video above). Most smartphones require a minimum of 0.5A to charge, while some need 1A. Tablets often require a minimum of 1A and sometimes as much as 2.1A to charge. You can still plug smartphones into these higher-powered ports. In fact, they'll charge faster if you do.
Other companies mark their ports by the name of the device you'll probably use with it. Apple and Samsung's power requirements tend to be a little different than your average USB device, which is why you see this happen. The manual should tell you the power each port provides, but you can make an educated guess by how they're labelled. iPad ports almost always provide 2 or 2.1A. So do Samsung ports, though some batteries offer 1.5A instead. Universal, Android or phone ports typically provide 1A of power, though in some rare cases you'll see 0.5A.
Most ports will work with most devices, with the exception of low-power ports and tablets. Those won't do anything, so make sure to save a higher-powered port for your higher-powered devices. If you check the power requirements in each device's manual, you should have no trouble matching them to the correct port on your battery. And, when in doubt, pretty much anything will charge on the high-powered 2.1A ports. With that basic information, you should have no trouble using your mobile battery as intended.