A power bank is a portable external battery used to charge phones and other devices when a wall outlet is unavailable. Understanding power bank usage and selection helps you stay connected away from home, whether you need a dedicated external battery or want to use your phone itself as a backup power source.
What is a power bank?
A power bank is a portable device that stores electrical energy and can be used to charge your gadgets when you don't have access to a wall socket. It essentially acts as a portable battery pack that you can carry with you wherever you go. Apple's MagSafe Battery Pack is the clearest official example of a phone power bank: it attaches magnetically to supported iPhone models and charges them wirelessly on the go. Apple says it supports iPhone 12, iPhone 12 Pro, iPhone 12 Pro Max, iPhone 13, iPhone 13 Pro, iPhone 14, and iPhone 14 Pro models. Apple documents that MagSafe Battery Pack use is limited to supported iPhone models listed above.
How power banks work
A power bank stores energy in its internal battery and transfers it to your device when connected. Apple documents that a MagSafe Battery Pack charges an iPhone by snapping to the back of the phone or MagSafe case, and it can also be recharged itself by connecting it to power with a cable and a compatible adapter. Google documents Battery Share as a reverse-wireless-charging feature that lets a Pixel phone charge another device by placing it back-to-back with the other device.
Types of power banks
There are three main types of power banks backed by official sources:
- Wired power banks: External batteries that charge a phone through a cable. Apple documents this general charging method for iPhone.
- Wireless/MagSafe power banks: Battery packs that attach and charge wirelessly. Apple documents MagSafe Battery Pack for supported iPhones.
- Reverse wireless charging phones: Phones that act like a power bank. Google documents this for Pixel via Battery Share.
How to use a phone as a power bank
Google's Battery Share feature lets you use a supported Pixel phone as a wireless power bank. To turn it on:
- Open Settings.
- Tap Battery.
- Tap Battery Share.
- Place your Pixel phone back-to-back with the device you want to charge.
Google says Battery Share is available on Google Pixel 5 and later, excluding Pixel A-Series and Google Pixel 9 Pro Fold.
Factors to consider when choosing a power bank
When selecting a power bank, consider these key factors to make an informed decision:
- Capacity: Measured in milliampere-hours (mAh), this determines how much charge the power bank can store. Higher capacity means more charges for your devices.
- Portability: Compact and lightweight designs are easier to carry in your bag or pocket.
- Number of ports: Multiple output ports allow you to charge several devices simultaneously.
- Output speed: Higher output currents enable faster charging for your devices.
Tips for using power banks safely
Follow these essential safety guidelines when using a power bank:
- Apple documents that MagSafe Battery Pack use requires supported iPhone models.
- Apple documents that the iPhone should not be charged through a keyboard unless the keyboard has a high-power USB port.
- Store and use power banks in a temperature range of 0°C to 45°C (32°F to 113°F). Avoid direct sunlight and extreme heat.
- Use the original cable and charger that came with the power bank or a certified replacement.
- Unplug the power bank once it is fully charged to prevent battery damage.
- Keep power banks away from water and moisture.
- Regularly inspect your power bank for signs of damage such as bulging, cracks, or frayed cables.
- Dispose of old power banks properly through electronic recycling centers.
Frequently Asked Questions
What capacity power bank do I need?
The capacity you need depends on your devices and charging habits. Smaller power banks around 3,000-5,000mAh are suitable for charging smartphones, while larger capacities from 10,000mAh to 20,000mAh or more are better for charging tablets and multiple devices.
How long does it take to charge a power bank?
Charging time depends on the power bank's capacity and the charging method. A power bank with a capacity of 10,000mAh may take around 4-6 hours to fully charge using a standard wall charger.
Are power banks safe to use?
When used properly, power banks are safe. Choose a power bank from a reputable manufacturer to ensure it adheres to safety standards, and avoid using damaged or faulty units. Always follow the manufacturer's instructions for proper usage and storage.
