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Our current picks are being discontinued, so we’ve added some new prospects to What to look forward to.

Working is hard, and when your laptop is close to dying, it’s even harder. Fortunately, a high-capacity power bank can save the day when you’re low on battery and outlets are out of reach—or if you need to charge your phone or another small device during a power outage. After 12 hours of research and 19 hours of testing, we’ve determined that the ZMI PowerPack 20000 is the best power bank for laptops that charge via USB-C. It fully recharges most laptops at least once at top speed, yet it’s compact enough to carry in a backpack, a laptop bag, or even most purses. Plus, it doubles as a hub, adding ports to your laptop.

The ZMI PowerPack 20000 can charge phones, tablets, and most laptops. It doubles as a hub, adding extra ports to your laptop, and it weighs less than a pound.

*At the time of publishing, the price was $60.

The ZMI PowerPack 20000 is the total package. Its hub functionality—an uncommon feature that we insisted on for the laptop-focused power banks in this guide because we think it’s particularly useful—lets you recharge a laptop over the USB-C port while also powering or transferring data to your other devices over its two USB-A ports. If you have a laptop that has only USB-C ports, this means you don’t need separate adapters to use USB-A devices such as wired mice or keyboards.

Charging efficiency always varies depending on the age of your devices and the number of programs you’re running, but the PowerPack 20000 has enough battery capacity to fully charge laptops such as the 13-inch MacBook Air or Dell XPS 13 at least once, the Nintendo Switch at least twice, or a smartphone like the iPhone 13 or Samsung Galaxy S21 about three times. And while some laptops need more power to charge at maximum speeds, the PowerPack 20000’s 40-watt-rated output is powerful enough to work with a wide range of models, charging smaller Chromebooks at their maximum speeds and larger MacBooks at respectable rates. To top it all, the PowerPack 20000 has a sleek, sophisticated look compared with most power banks—it’s not much bigger than a Hershey’s chocolate bar, and it weighs less than a pound.

Maximum measured output: 40 watts Maximum measured input: 60 watts Capacity rating: 20,000 mAh Weight: 0.9 pound

This sleek, slim charger has two USB-A ports and a USB-C port that lets you charge most laptops (and the charger itself) with up to 60 watts of power.

*At the time of publishing, the price was $86.

If you have a large, power-hungry laptop (for gaming or video and photo editing, for instance) and want to charge it while running lots of programs, the ZMI PowerPack 20K Pro is better suited to your needs than the PowerPack 20000. It’s nearly identical, except it offers a higher maximum output rating (60 watts) than any other portable charger we’ve tested. It’s not our top pick because it won’t offer a noticeable improvement for most people, especially with Chromebooks and other laptops that don’t need the extra power, and at this writing it costs about $30 more. But the PowerPack 20K Pro is a great option if you want to charge a heavy-duty laptop (or even a moderately sized laptop like the 13-inch MacBook Pro at the fastest possible speed), or if our top pick is out of stock.

Like the PowerPack 20000, the PowerPack 20K Pro doubles as a hub, so you can plug keyboards, flash drives, and other peripheral devices into its USB-A ports. Just like its twin, it weighs just 0.9 pound, and it’s slim and sleek enough to be easily slipped into a backpack or briefcase pocket. It also has the same rated capacity and the same USB-A output ports.

Maximum measured output: 60 watts Maximum measured input: 60 watts Capacity rating: 20,000 mAh Weight: 0.9 pound

The ZMI PowerPack 20000 can charge phones, tablets, and most laptops. It doubles as a hub, adding extra ports to your laptop, and it weighs less than a pound.

*At the time of publishing, the price was $60.

This sleek, slim charger has two USB-A ports and a USB-C port that lets you charge most laptops (and the charger itself) with up to 60 watts of power.

*At the time of publishing, the price was $86.

As the writer of this guide, I spent 12 hours researching and 19 hours testing portable laptop chargers (also called USB power banks or battery packs). I’ve been a science writer for more than seven years, covering a wide variety of topics from particle physics to satellite remote sensing. Since joining Wirecutter in 2017, I’ve reported on portable solar battery chargers, USB-C cables and adapters, surge protectors, and more.

To learn more about how to recycle portable laptop chargers and other batteries, I interviewed Joe Day, director of global business development at TerraCycle Regulated Waste, a private firm specializing in hard-to-recycle materials; Linda Gabor, director of external relations at Call2Recycle, a battery-recycling nonprofit; and Call2Recycle CEO Leo Raudys. I also interviewed Isidor Buchmann, CEO of Cadex Electronics, for background on how batteries work and how to extend their lifespans.

If you have a laptop that charges over USB-C—such as a MacBook, Chromebook, or one of many other modern laptops—and you frequently use it in a coffee shop, on a plane, and in other places where wall outlets can be scarce, you should get one of the power banks in this guide. A power bank is a handy backup for those moments when your laptop battery is low and there’s no outlet in sight. And it will keep your laptop running for hours, so you can work (or watch downloaded episodes of I Think You Should Leave) on long flights or train rides.

Beyond being a simple convenience, a high-capacity power bank is also good in case of emergency. Ready.gov recommends keeping “a back-up power source on hand to recharge your phone so that you can stay connected even during an extended power outage.” Stowing one of these in a bug-out bag is a good way to prepare for wildfires, flooding, and other emergency situations. Or, pack one in a hospital go bag to keep electronics powered during labor, an unexpected surgery, or other medical emergency.

If you’re looking for something you can carry around in a pocket or a purse to power your phone, tablet, and other small devices, you’re better off getting one of our lower-capacity picks.

Our picks for the best power banks let you pack hours of extra battery life in a pocket or purse to charge your phone, tablet, or other small handheld device.

If you want to power a laptop or other high-powered device that charges from an AC plug—the kind you’d usually plug into a wall outlet—you should get one of our favorite portable laptop chargers with an AC outlet. For tailgating, camping, or other heavy-duty powering, we also have recommendations for much larger portable power stations and generators.

When wall outlets are scarce, a portable laptop charger can be a handy backup for travelers, remote workers, and others. Anker’s Powerhouse 100 is our favorite.

We checked out major retailers such as Best Buy and Amazon to find the most well-known and widely available makers of portable laptop chargers. From there, we built a list of contenders based on the following features:

This process left us with a list of six contenders for testing:

We tested the performance of each power bank in a few key areas, including:

The ZMI PowerPack 20000 can charge phones, tablets, and most laptops. It doubles as a hub, adding extra ports to your laptop, and it weighs less than a pound.

*At the time of publishing, the price was $60.

The ZMI PowerPack 20000 is powerful enough to charge a wide range of laptops yet small enough to carry all day in any backpack or laptop bag, and most purses. It’s aesthetically pleasing, too. Plus, it offers a higher capacity (mAh) per dollar—more bang for your buck—compared with most of the other power banks we considered. With its 40 W maximum output, it’s ideal for lower-powered laptops like Chromebooks and will charge moderately sized laptops like the 13-inch MacBook at an acceptable pace, but if you have a higher-powered machine like the 16-inch MacBook Pro you should consider our 60 W also-great pick.

The PowerPack 20000 is easy and intuitive to use: Simply charge it from the USB-C port and then charge your devices over USB-C or USB-A. Its hub functionality allows you to add USB-A ports to your laptop, passing power and data to and from your other devices over the USB-C cable, which is a handy way to avoid adapters if you need to plug something like a smartphone or a portable SSD into your laptop. This feature is easy to turn on: Just press the power button twice and wait for a little light (different from the power indicator lights) to turn green.

The PowerPack 20000’s rated maximum output is 45 watts—we measured 40 watts in our testing—which is more than enough power to charge most laptops. But high-powered laptops such as the 16-inch MacBook Pro might drain faster than they charge during heavy workloads, in which case a power bank with 60-watt output or more (like our also-great pick) would be the better choice. In our testing, this model charged a Dell XPS 13 from zero to 50% in an hour.

We also measured a maximum input of 60 watts, showing that the PowerPack 20000 recharges itself at top speed. It’s rated to fully recharge in about four hours with a 45-watt USB-C PD charger, or in about nine hours with a conventional 10-watt USB-A wall charger.

This ZMI power pack has two USB-A ports, like most of the models we tested (the Zendure is the exception, with four USB-A ports). We measured an output of 12.3 watts and 13.4 watts on the two ports, respectively. This means you can charge devices such as smartphones or wireless headphones over USB-A as fast as you can with even the best USB-A wall chargers, and more than twice as fast as with a 5-watt charger like Apple’s standard charging brick. Our tests confirmed that charging a 13-inch MacBook Pro and two smaller devices (represented by Drok USB Load Testers set to draw 2 amps of power) at the same time does not significantly slow down charging speeds.

If you have a typical 13-inch laptop, you should expect the PowerPack 20000 to give it about one full charge, depending on your laptop battery’s capacity. The pack has a rated capacity of 20,000 mAh (or around 74 watt-hours), which is still low enough for you to pack it in a carry-on per TSA regulations.

The PowerPack 20000 is slim and compact, and it has a sleek metallic, dark blue exterior. Its smooth finish and rounded edges make it comfortable to hold and easy to slip into a bag. Weighing less than a pound (14.2 ounces), it’s lighter than an iPad Mini. Four little battery-status lights (on the side of the power bank next to the power button) tell you how much charge is left, which is a convenient detail.

This power bank comes with a USB-C cable, a 2-in-1 cable (a Micro-USB cable with a USB-C adapter attached by a small tether), and a soft carrying pouch to keep dust and moisture out of the ports while in transit. ZMI backs the PowerPack 20000 with an 18-month warranty—during which time you can power your laptop in countless planes, coffee shops, and conference halls to confirm that it works properly.

Although we wish the ZMI PowerPack 20000’s capacity was higher, none of the other models we tested offer anything close to the TSA’s 26,800 mAh maximum limit (the ZMI PowerPack No. 20 Model QB826G has the highest capacity rating, at 25,000 mAh, but lacks other key features).

This power bank doesn’t come with a USB wall charger, but most models we tested don’t either, and if your laptop or phone charges over USB-C, you probably already have a compatible charger that you can bring with you.

After using this power bank for nearly three years, while traveling internationally and working from countless coffee shops and coworking spaces, we’ve noticed some wear and tear on our unit. Its dark-blue paint has accumulated lots of scuffs and scratches, especially around the edges (no doubt from rubbing up against metal laptops and other gear inside a backpack or bag organizer). We’d prefer a more durable finish, especially for people who handle their stuff even rougher than we do. But since its internals have withstood the test of time, we can easily overlook these cosmetic imperfections.

This sleek, slim charger has two USB-A ports and a USB-C port that lets you charge most laptops (and the charger itself) with up to 60 watts of power.

*At the time of publishing, the price was $86.

The ZMI PowerPack 20K Pro is nearly identical to our top pick, with the key difference being that it can output 60 watts compared with 40 watts, which is what the PowerPack 20000 provides. That makes it a better option for people who own a more power-hungry laptop like a MacBook Pro. Output aside, it mirrors the PowerPack 20000 in that it doubles as a hub, it has two high-amp USB-A output ports and a fast-charging USB-C PD input/output port, and it has a capacity rating of 20,000 mAh. Plus, like the PowerPack 20000, the PowerPack 20K Pro weighs less than a pound (both chargers weigh just over 14 ounces each), it can be fully recharged in as little as four hours with the right wall charger, and its sleek, slim shape makes it easy to pack up and go. It’s also backed by ZMI’s 18-month warranty.

While most laptop owners should be satisfied with the results they get from our top pick, the 20K Pro’s boosted output is an exciting improvement for owners of the 13-inch MacBook Pro (which ships with a 61-watt wall charger) and its 14- and 16-inch siblings (which can draw up to 96 and 140 watts, respectively). But you don’t need a MacBook Pro to enjoy the benefits of a more powerful charger: If your machine draws more than 40 watts and you want to charge your laptop as fast as possible—or while it’s running lots of programs—the PowerPack 20K Pro is your best bet.

This power bank comes with two USB-C charging cables (an A-to-C cable and a C-to-C cable) and a soft, protective carrying pouch. Like its dark-blue twin, it doesn’t come with a USB wall charger so you’ll have to buy one separately or use one you already have for a phone or laptop.

Like the ZMI PowerPack 20000, the PowerPack 20K Pro has less capacity than other models we considered. The ZMI PowerPack No. 20 Model QB826G and the discontinued Anker PowerCore+ 19000 PD, RAVPower RP-PB059, and Zendure X69 all have capacity ratings exceeding 20,000 mAh. But we think the ZMI models’ sleek look, slim profile, and high input/output wattage are well worth the slight loss in capacity.

At this writing, the PowerPack 20K Pro costs more than the PowerPack 20000. We think you’re better off saving a couple of bucks and getting our top pick unless you need the extra power that the PowerPack 20K Pro provides.

In case of a power outage, the picks in this guide can keep a phone, a rechargeable lantern, and another small essential device powered for an hour or more. This is a far more sustainable option than firing up a gas-powered generator or car engine to charge such low-wattage devices.

One of the most sustainable things you can do with a portable laptop charger—since most, if not all, of its components are made of non-renewable, non-biodegradable materials—is to take good care of it so you don’t have to replace it as often. Most of the models we tested come with protective cases to keep moisture, dust, and other debris out of the exposed ports, and many backpacks and tote bags are equipped with protective pockets for electronics, but you should still make sure to handle your power bank with care to avoid scratches, scuffs, and dents.

Although most of the power banks in this guide are rated to operate in temperatures ranging from 32 °F to 100 °F, long periods in extreme temps (below freezing or above 86 °F) can cause permanent damage to the battery. To be on the safe side, don’t leave your portable laptop charger (or any battery-operated device, really) in your car or a poorly insulated room when it’s especially cold or hot out. Ideally, you should store your portable laptop charger in a cool, dry place—preferably at about a 40% charge—to maximize its lifespan.

Lithium-ion batteries are notoriously hard to dispose of safely, but it’s still important to recycle your power bank when it reaches the end of its life. Recycling facilities can salvage usable components from old electronics, reducing the amount of raw materials that must be mined to make new ones. Also, batteries that are not recycled and end up in a landfill can leach heavy metals and other harmful chemicals into local soil and water systems. While most Americans recycle plastic, metal, paper, and cardboard on a regular basis, less than half recycle their used batteries and other electronic waste (e-waste). Here are some of the best options we’ve found for recycling e-waste:

ZMI is discontinuing both of our picks, so we’re planning to test the following models to replace them as soon as we can:

If you’re willing to pay more than twice as much for more power, an extra USB-C port, wireless charging, and an informative screen: You should get the Omnicharge Omni 20c+. It has two USB-C PD ports (one rated for 100 W output, and the other rated for 60 W), two USB-A ports (each rated for 18 W), and a wireless-charging pad (rated for 10 W) that can charge most supported phones at top speed. Based on our testing, it can be recharged in about five hours with a 45 W wall charger (like our picks, a charger isn’t included, though it comes with a USB-C cable). It has the rare (but super useful) hub feature that we preferred every model to have, as well as a capacity rating of 20,100 mAh, which is slightly higher than our picks. It’s sturdily built, has rounded corners that make it easy to grasp and slide into a bag, and its matte-black finish is pleasantly grippy. Its OLED screen is small yet bright, showing in/out wattage, battery status, operating temperature, and which ports are powered on. Most people don’t need such granular information, and the text is painfully tiny, but it has the potential to be useful (for instance, if the operating temperature gets dangerously high, you can shut down the unit to prevent lasting damage). The Omnicharge is backed by a one-year warranty, which is a tad shorter than our picks but still gives plenty of time to ensure that it’s working properly. Other than the price, the biggest drawback is that it weighs over a pound (1.4 pounds, or nearly twice as much as our picks), but its compact shape helps make up for the extra bulk. You can also get a hardshell case, sold separately, if you’re worried about dust or moisture getting into the ports.

If you want the fastest charging speeds for large, heavy-duty laptops and a larger battery capacity: Consider the ZMI PowerPack No. 20 Model QB826G. It has the highest capacity rating (25,000 mAh) and some of the highest output ratings of any model we’ve tested, with two USB-C PD ports (one rated for 100 W output, and the other rated for 45 W) as well as a USB-A port rated for up to 100 W output. Based on our testing, it can recharge itself in as little as 2½ hours from the 100 W port, or as little as 5 hours from the 45 W port. Like our picks, it’s backed by ZMI’s 18-month warranty, and it comes with two charging cables but no wall charger. It’s not one of our picks because it lacks hub functionality, weighs over a pound (1.3 pounds), and our picks provide plenty of power for most people at a fraction of the price, but it’s still a good option if you want the extra capacity and speed.

We tested the Anker PowerCore+ 19000 PD (discontinued) in a previous round of testing, but it failed to outshine other options costing a lot less.

The RAVPower RP-PB059 used to be a runner-up pick, and the Zendure X6 was formerly an also-great pick, but they’ve been discontinued.

While researching dozens of portable laptop chargers, we found several options that met one or more of our criteria but failed to measure up in other key ways. We dismissed the following models without testing them because they lack hub functionality, their capacity or output rating is lower than our set parameters, and/or they cost significantly more than our picks:

Sarah Witman has researched, tested, and reviewed all manner of products—from massage chairs and mousetraps to pencils and power banks—since joining Wirecutter in 2017. Before that, she worked as a science writer and fact checker for numerous publications, and she studied journalism at the University of Wisconsin. In her spare time, she eats as much cheese as her body will tolerate.

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