Super svelte, about the same size as a stack of credit cards, this charger slides easily into pockets and bags and offers a modest top-up for your phone.

Anker’s dinky charger comes in fun colors and simply slots into the bottom of your phone via the built-in rotating USB-C or Lightning connector.

Redmagic’s Go Power Bank combines a cool, modular look with a thoughtful and practical design, doubling as a 65-watt charger.

This wafer thin Qi2 power bank clings to the back of your phone magnetically for up to 15-watt wireless charging, providing enhanced safety and reduced fire risk.

This model has a 2.3-foot retractable cable and the ability to charge devices at up to 45 watts.

Handmade by a small indie business in Brighton, UK, from recycled plastic, Gomi claims at least 50 percent less CO₂ emissions than other power banks.

Not just a cute, wee robot face, this is also a super-speedy power bank offering up to 100 watts, unusual in a charger this size.

Capable of delivering 300 watts, this power bank is close to the maximum capacity allowed on flights, and it can charge a couple of laptops and phones at the same time via the three USB-C ports (140W, 65W, 65W) and retractable 2-foot USB-C cable (140W).

This high-capacity portable power bank delivers up to 67 watts, with 2.3 feet of built-in USB-C cable when fully extended, but you can pull and stop at shorter lengths, and there’s also a USB-C port.

Looking like a power bank from the Nostromo, this can deliver a chart-topping 240 watts for two devices via the USB-C ports (140 watts and 100 watts), making it a good choice if you want to charge two laptops simultaneously.

Feature-packed with 26,250 mAh at 300 watts across two USB-C ports and one USB-A, a smart display and app control, and a 3.3-foot USB-C cable, this Anker Prime Power Bank is a beast.

Travel plug adapters cover trips to the UK, Europe, and Australia, among other places. It also has three ports and a magnetic Qi2 wireless charging pad.

You get slide-on Type C, I, and G plug adapters for travel, a magnetic wireless charger (up to 15 watts), USB-A and USB-C ports, and built-in USB-C and Lightning cables.

This 1,000-amp, 12-volt battery pack comes with jump leads to start a car with a dead battery and has a USB-A port to charge your phone and a built-in 100-lumen flashlight.

Thoughtfully designed power banks with an IP67 rating, built-in shock absorbers, and screw-on caps for the ports.

This portable charger has a whopping 90,000-mAh capacity, a pop-up lantern, and a versatile array of ports.

The Charge 100 Max can simultaneously charge up to five devices, and the wireless charging pad on top is handy in the dark when you don’t want to fumble with cables.

What Features Should I Look for in Power Banks?

There are a few things worth thinking about when you’re shopping for a portable charger.

The capacity of a power bank is measured in milliampere-hours (mAh), but this can be a little misleading because the amount of power you get out depends on the cable you use, the device you're charging, and the charging method (Qi wireless charging is less efficient). You will never get the maximum capacity from any power bank. You can generally expect to get between 60 and 80 percent after energy loss through heat and conversion. Some manufacturers list a “Rated Capacity” that's lower than the overall capacity to give you an indication of what to expect in real world use. We try to provide a minimum estimate of what you’ll get in terms of charges for devices.

The charging rate for devices like smartphones is measured in watts (W), but most power banks list the voltage (V) and the amperage (A). Thankfully, you can calculate the wattage yourself simply by multiplying the voltage and amperage. Unfortunately, getting that maximum rate also depends on your device, the standards it supports, and the charging cable you use. Many smartphones, including Apple’s iPhones, support the power delivery standard, meaning you can use higher-power power banks to recharge the device with no issues. A few phones, such as Samsung’s Galaxy S range, support a supplementary PD protocol called PPS (Programmable Power Supply) that goes up to 45 watts. Many phones also support Qualcomm’s proprietary Quick Charge (QC) standard. There are also other proprietary fast-charging standards, but you won’t generally find power banks that support them unless they come from the smartphone manufacturer.

Your device will need pass-through support if you want to charge your power bank and use it to charge another device simultaneously. The Nimble, GoalZero, Biolite, Mophie, Zendure, and Sharge portable chargers listed support pass-through charging. Anker discontinued support for pass-through in some of its products because it found that differences between the output of the wall charger and the input of the device being charged can cause the power bank to cycle on and off rapidly and shorten its life. Monoprice does not support pass-through charging either. We would advise caution when using pass-through, as it can also cause portable chargers to heat up.

Can I Take a Power Bank on a Plane?

It’s safe to fly with a power bank, but there are two main restrictions to keep in mind when you board a flight: You must have the portable charger in your carry-on luggage (it cannot be checked), and it must not exceed 100 watt-hours (WH). If your power bank has a larger capacity than 27,000 mAh, you should check with the airline. Below that should not be a problem.

Some airlines introduced stricter rules in 2025, so always check with your chosen airline before you travel. For example, some airlines prefer you not to use or charge power banks during a flight, some require power banks to be in your hand luggage under the seat in front of you and not in the overheads, and some limit the number of power banks you can have onboard.

Why You Should Avoid Cheap Power Banks

Many years ago, the Samsung Galaxy Note 7 gained notoriety when its batteries caught fire in a series of incidents. There's been a steady stream of similar, though isolated, incidents ever since. However, despite the high-profile coverage of batteries gone wrong, the vast majority of lithium-ion batteries are safe.

The chemical reaction that occurs inside a lithium-ion cell is complex, but as in any battery, there's a negative and a positive electrode. In lithium batteries, the negative is a lithium-carbon compound, and the positive is cobalt oxide (though many battery makers are moving away from cobalt). These two compounds cause a reaction that is safe when controlled and delivers energy to your devices. When the reaction gets out of control, though, you end up with earbuds melting in your ears. What changes a safe reaction to an uncontrolled reaction can be any number of things: excess heat, physical damage during use, physical damage during manufacture, or using the wrong charger.

The three basic rules that have kept me safe through testing dozens and dozens of batteries are these:

1. Avoid cheap cords, chargers, and outlet adapters;
2. Make sure batteries aren't exposed to excessive heat (above 110 degrees Fahrenheit);
3. Regularly inspect batteries for signs of damage.

Avoiding cheap wall-outlet adapters, cords, and chargers is the most important. These are your most likely source of problems. Those chargers you see on Amazon for $20 cheaper than the competition? Not worth it. They probably got the price down by skimping on insulation, leaving out power-management tools, and ignoring the basics of electrical safety. Price alone is no guarantee of safety, either. Buy from reputable companies and brands.

Then there's heat. Too much of it can cause all manner of problems, both in terms of discharge and in terms of safety. Avoid heat, and pay attention to your batteries when they're charging. If your device gets overly hot when charging, this can be a sign of problems. Similarly, beware of any swollen, bulging, or otherwise misshapen batteries.

Why is My Power Bank Charging Slowly?

I’ve explained charging rates and capacity above, but several factors can cause charging speed to be slower than expected. The rate is determined by the device being charged, so your phone will request a certain wattage, which changes depending on how full its battery is, on-device settings, and the battery temperature.

All devices charge more slowly when they are completely empty, when the battery approaches full, and when it overheats. The cable you use will also have a maximum charging rate, and so will different ports on the power bank. Wireless charging is more convenient, but also slower than wired charging.

How We Test Power Banks

I've been testing power banks for close to two decades, and my home office has stacks of ’em at any given moment. I test every portable charger that comes in for at least two weeks. I always check how many times it can fully charge my test phone (currently an iPhone 16). I'll also try charging my Pixel 10 Pro XL and Samsung Galaxy S24+ to test charging speeds, and whatever else I have in. For larger-capacity power banks, I test-charge an iPad Mini and a MacBook Air. I test how long it takes to recharge each empty power bank.

Aside from these standard tests, I try to use the power banks in my everyday life, just to see how they feel, and my wife and kids often help out and share their opinions. For some of our top picks, I continue to test over months to get a sense of their reliability and durability, though it's not possible to do this for every device that lands on my desk. Beyond function, I take form and usability into account. I keep an eye on user reviews and consider the warranties and customer service of each manufacturer.

How Does WIRED Select Power Banks to be Reviewed?

I often scan the latest releases to seek out worthy prospects, whether from an unknown new brand or an established favorite like Anker. I also get pitched many power banks every week. I sometimes reach out to these companies to ask for the product but never promise any kind of editorial coverage—that would be against WIRED's editorial policies. While WIRED usually earns affiliate revenue if you purchase a power bank using our link, this is not factored into the decision process when ranking.

There are too many power banks for me to test everything, so I tend to stick to reputable brands, but there's always room for something new if it has a compelling new feature or price, and I cover as many as I can. (Leave a comment or send me an email if you want me to test a power bank from a certain brand!) Once testing is complete, I typically donate power banks to a local charity. I try to hang on to some of our top picks for comparison purposes and to test their longevity.