These days, "small" portable batteries have a capacity of around 5,000mAh, which means they easily fit into your pocket and still have enough power to fully top up your phone once. Meanwhile, a 10,000mAh battery can give today's flagship phoness two full charges. A 20,000mAh battery can charge two phones twice,. Generally speaking, you charge the battery itself via USB-C (input). Speeds differ depending on the battery you choose. Many batteries also still include a standard USB-A port (output). This is for plugging in USB-A-to-Lightning or USB-A-to-USB-C cables for. Pass-through charging is another feature to consider; with it, you can charge your device and a portable power bank simultaneously. That's convenient if both your phone and backup battery are running on empty. You shouldn't encounter any safety. Another factor to consider is how quickly a power bank can charge your device. Battery output is measured in voltage and amperage. Amperage (or current) is the amount of electricity. Wireless charging has become popular because it allows you to power up compatible devices without a cable. Qi is the dominant standard for compatible Android phones (up to 15W), while Apple iPhones rely on MagSafe charging (up to 25W). iPhones will.
