Mobile Phones Android What Is A Portable Charger? What to know about the handheld power banks you can carry anywhere By Mark Thomas Knapp Updated May 06, 2019 Diane Macdonald/Getty Images Android Switching from iOS Tweet Share Email A portable charger, sometimes called a power bank, is simply a reusable battery that can be charged over and over again for multiple uses. It's usually small enough to fit in your hand. Covered by a protective casing, it can connect to any variety of input and output sources, allowing you charge various devices (a smartphone or a laptop, for instance) from almost anywhere without the need for a wall outlet. Portable chargers can come in a wide variety of forms and have a broad range of features, but the most essential aspect is that they have a rechargeable battery built-in that is used for extending the power and use time of your other devices. Many smartphones have battery capacities measured in mAh (Milliamp Hours), and tend to range between 2,000mAh and 5,000mAh, though there are the occasional differences. Typical battery banks used for powering phones and laptops will also have their battery capacity measured in Milliamp Hours, which makes it easy to determine which size charger you need for a specific device. How Portable Chargers Work Instead of charging your phone, tablet, or other device directly from a wall outlet, you charge it instead from the power stored in the portable charger by inserting the charger (or charger cable) to the device that needs power. You can always check the charge on the device you are recharging (i.e. your phone) to see whether or not it is fully charged up. Given the short lifespan of many smartphones, many of the most popular and best portable chargers are USB devices. These usually are on the smaller side so they can easily come along with you in a pocket or purse and extend your phone’s battery life. Portable chargers are often equipped with one or more USB ports allowing them to connect to nearly any variety of cable used to charge modern smartphones. Standard Micro-USB, USB-C, and Apple Lightning cables ending with a USB Type-A are some of the most common connections you’ll be looking for to use with a portable charger. How to Use A Portable Charger Portable chargers come in an incredible variety, and that means there’s no hard and fast rule about how they work or how you’ll charge them. Many of the smaller portable chargers are recharged over Micro-USB or USB Type-C connections, while larger battery banks may use DC connectors like you might find on laptops and other electronics. There are even solar-powered portable chargers on the market. Learn more about USB connections Power banks will charge like just about any other electronic device with a rechargeable battery built-in. Some may charge faster because of the connector used or because a smaller capacity battery can recharge more quickly. To charge a device using a portable charger, just connect your device to the portable charger and turn the charger's power on. It will begin charging the dead or low-powered device. Some chargers provide an indicator to show you when the charge is done; some do not. What Else Can Portable Chargers Do? While the most basic portable chargers will just offer a USB output to charge one device, other (usually more expensive) chargers will offer whole host of special features. Some offer support for various quick charging technologies, letting you top up your smartphone extra quickly. Some include multiple USB ports so you can keep multiple devices charging at the same time. That’s just what portable chargers can do for smartphones, tablets, and the like. Some portable chargers have a lot more utility, with three-prong outlets, DC power, and flashlights not uncommon. Some portable chargers for laptops offer up a ton of power to keep energy-hungry computers powered. There are even specialized power banks for jumping cars that include a port to directly connect alligator clip cables. Some portable chargers offer charging for a single-use only. That means you can use it just one time, then you must dispose of it. If you think you'll need to use one more often than that, double-check the package to be sure the charger you choose can be recharged over and over for multiple uses. Single-use portable chargers can be handy in some situations and are good for very tight budgets; multiple-use chargers are a better choice for people who frequently need to recharge devices when away from home. With all the capacities available and features, there’s a portable charger for just about any device you’re trying to keep powered on.