Being faced with a near-dead phone and no way to recharge can be a little panic-inducing. A portable power bank can help keep that feeling at bay, giving your devices a quick charge no matter how far you stray from an outlet. Toss a small one in your pack for a partial refill on a smartphone, or grab a higher-capacity battery to take to the diner where you’ll park it for the day to work on your laptop. We’ve tested dozens of battery packs for this guide over the past year to come up with our top picks and help you find the best portable charger to fit your needs.
What to look for in a portable battery pack
Battery type
Nearly every rechargeable power bank you can buy (and most portable devices) contain a lithium-ion battery. These beat other current battery types in terms of size-to-charge capacity, and have even increased in energy density by eight fold in the past 14 years. They also don’t suffer from a memory effect (where battery life deteriorates due to partial charges).
One drawback you may have heard is the possibility of lithium ion batteries catching fire. To limit the danger, battery packs require internal mechanisms to limit things like voltage and pressure. While you should still make sure a battery isn’t exposed to unnecessary stress like excessive heat, damage from drops or operating in freezing weather, battery packs are considered safe enough to bring on an airplane. According to the TSA, external batteries rated at 100Wh or less (which all of our recommendations are) can fly with you – just make sure you stash them in your carryon as they aren’t allowed in checked baggage.
Capacity
Power bank manufacturers almost always list a battery’s capacity in milliamp hours, or mAh. Smaller batteries, say those that can charge a smartphone to between 50 and 75 percent, tend to have a 5,000mAh capacity. Larger batteries that can recharge laptops and tablets, or give phones multiple charges, can exceed 25,000mAh. Unsurprisingly, the prices on most batteries goes up as mAh capacity increases, and since batteries are physical storage units, size and weight go up with capacity as well. If you want more power, be prepared to spend more and carry around a heavier brick.
You might think that a 10,000mAh power bank could charge a 5,000mAh phone to 100 percent twice, but that’s not the case. In addition to simple energy loss through heat dissipation, factors like voltage conversion also bring down the amount of juice that makes it into your phone. Most manufacturers list how many charges a battery can give a certain smartphone. In our tests, 10,000mAh of battery pack capacity translated to roughly 5,800mAh of device charge. 20,000mAh chargers delivered around 11,250mAh to a device, and 25,000mAh banks translated to about 16,200mAh of charge. That’s an average efficiency rate of around 60 percent.
Ports
Since Apple finally ditched the Lightning cable and adopted USB-C, we’re getting closer to a standard for charging connections — and all of our picks have at least one such port. But plenty of other devices use older interfaces, like USB-A and microUSB ports, plus Lightning for older iPhones. You can find cables with just about any combination of those connections, so when you’re picking out a battery, just check that one end of your preferred cord will fit.
Most battery packs have more than one port, which gives you different charging options. You’ll typically see at least one port labeled “in/out,” which means you can use it to both charge the bank and charge your device. While USB-A output ports can power up smartphones and other small devices, they can’t charge larger devices. Plus, they aren’t as fast as USB-C ports overall. That’s something to keep in mind when you’re deciding which ports and charging cables to use to connect your phone to the pack.
There’s even more variation among USB-C ports themselves, with different ports on the same device supporting different power transfer rates. What that means in practical terms is an iPhone will charge just fine plugged into a power bank’s 18W port. But to properly charge, say, a MacBook or similar laptop, it’ll need the extra juice supplied by a 100W port (which larger power banks can offer). Power banks with more than one port can also charge multiple devices at the same time, but speeds and the overall charge delivered will be lower.
You’ll also want to consider your charging cable. For anything larger than a smartphone (and to access fast-charging capabilities) you’ll want to use USB-C ports and cables. But not all cables are created equal, even when they have the same USB-C plugs on the end. If you want power delivery from a 100W USB-C power bank port, you’ll need a 100W-rated USB-C cable. Luckily, power banks capable of delivering 100W tend to include a compatible cable. For any devices that don’t, we’ve tried and liked Anker’s 100W USB-C cable. For smaller devices, we used this 60W cable from Nimble and we don’t recommend bothering with cables under 60W. For around $20, higher-capacity charging cables will make sure you’re not wasting time with connections that limit your potential power transfer.
Design
For the most part, these rechargeable batteries have a squared-off, brick-like design, though many nod towards aesthetics with attractive finishes and detailing. While that doesn’t affect how they perform, it’s a consideration for something you’ll interact with regularly. Some portable power stations include extra features like MagSafe compatibility, a built-in wall plug or even a kickstand. Nearly all have some sort of indicator to let you know how much available charge your power bank has left, usually expressed with lighted pips near the power button. Some of the newer banks take that a step further with an LED display indicating remaining battery percentage.
How we test portable battery packs
Before we even put our hands on a battery pack, we did extensive research. We considered brands Engadget reviewers and staff have tried over the years and we checked out customer ratings on retail sites like Amazon and Best Buy. Here’s the full list of power banks we’ve tested, which range from small wireless banks to large, multi-device batteries.
MagSafe-compatible
Low capacity (≤10,000mAh)
Mid capacity (10,001 – 20,000mAh)
High capacity (20,001mAh+)
We’re continuously updating this guide as companies release new products and we test them. We remove some products as we find better top picks, and we add updated specs and prices where necessary. For testing, we used each battery with some combination of an iPhone 15, an iPhone 14 Plus, an iPhone 11, a Samsung Galaxy S22 Ultra, a 5th-gen iPad Air and an M1 Pro 16-inch MacBook Pro. I charged one phone battery at a time, even though some packs are capable of multiple-device charging. I charged the phones and tablets from between zero and five percent until they were 100 percent full (or until the power bank was dead), and didn’t use the device while they charged other than to power them on and enter the unlock code.
I used the charging cable included with each power bank to charge the Galaxy S22 Ultra, MacBook Pro and the iPad Air. For the iPhones, I used the USB-C to Lighting cable that Apple provides. In the case of the lower-capacity power banks that didn’t include a cord or included one with USB-C to USB-A connectors, I used this 60W-rated USB-C to USB-C cable.
For reference, here are the battery capacities of each device we used for testing:
I noted the times for each charge and the number of charges each bank provided. I also paid attention to things like ease of use and overall design.
The best portable power banks for 2024
Photo by Amy Skorheim / Engadget
Capacity: 10,000mAh, 15W | Ports: One USB-C in/out | Included cable: USB-C to USB-C | Number of charges iPhone 15: 1.64 | Charge time iPhone: 4 to 100% in 2h 26m and 0 to 70% in 1h 8m
Anker’s MagGo Power Bank was one of the first Qi2-certified products to come on the market, and the new standard has made the brand’s popular MagSafe/kickstand model much faster. It brought an iPhone 15 from near-dead to half-full in about 45 minutes. For reference, it took our former top pick in this category an hour and a half to do the same. It’s similarly faster than Anker’s previous generation of this model, the 633, as well. After that initial refill, the MagGo 10K had enough left over to get the phone up to 70 percent on a subsequent charge.
In addition to faster charging speeds, this Anker power bank adds a small display to indicate the battery percentage left in the bank, plus the approximate amount of time before it’s full (when it’s refilling) or empty (when it’s doing the charging). A strong MagSafe connection makes it easy to use the phone while it charges and the small kickstand creates a surprisingly sturdy base for watching videos and the like. If you twist the phone to landscape, StandBy mode kicks in.
The power bank did a fine job of charging our Galaxy S23 Ultra, but the lack of support for Qi2, even on the newest Galaxies and Pixels, means the most popular Android will simply charge at a slower rate — and won’t benefit from the zero-effort magnetic alignment. There’s also a single USB-C port for recharging, so if you need to fill up something without wireless capabilities, you can.
- Qi2 tech enables extra fast wireless charging
- Sturdy kickstand props up iPhones as it charges
- LED display for battery percentage
- More expensive than other MagSafe packs
Photo by Amy Skorheim / Engadget
Capacity: 5,000 mAh, 22.5W max | Ports: One USB-C and one USB-C connector | Cable: USB-C to USB-C | Number of charges Galaxy S23 Ultra: 0.65 | Charge time: 0 to 65% in 1h 2m
The Anker Nano power bank is impressive for how much charge it delivers in such a small package. It’s the exact size and shape of the lipstick case my grandma used to carry and has a built-in USB-C connector that folds down when you’re not using it. That means that, in addition to being ultra-portable, you also don’t need to remember to grab a charging cable when you toss it in your bag. There’s also a built-in USB-C port that can refill the battery or be used to fill up a different device with an adapter cable. You also get four indicator lights that let you know how much charge remains in the battery.
In my testing, the 5,000mAh battery provided enough charge to get a depleted Galaxy S23 Ultra back up to 65 percent in about an hour. That’s relatively quick, but the Nano is also small enough that, with an adequately sturdy connection, you can use your phone while it’s charging without feeling too awkward. The charger’s small size also makes it a good pick for recharging earbuds.
For a little more juice and an equally clever design, Anker’s 30W Nano Power Bank is a good option. It’s bigger in size and capacity (10,000mAh) and includes a display indicating the remaining charge percentage. The attached USB-C cable doubles as a carry handle, which is a nice touch. That cable is in/out and there’s another USB-C in-out port in addition to an out-only USB-A port.
- Small enough to get misplaced
BioLite
Capacity: 10,000mAh, 18W max | Ports: One in/out USB-C, two USB-A out only | Cable: USB-C to USB-A | Number of charges iPhone 14 Plus: 1.36 | Charge time iPhone: 0 to 100% in 1h 50m, 0 to 50% in 36m | Number of charges Galaxy S22 Ultra: 1.33 | Charge time Galaxy: 0 to 100% in 1h 33m, 0 to 50% in 45m
BioLite is probably better known in the outdoor community than the tech world, and it’s fair to say that the Charge 40 PD is geared more towards camping trips than urban commutes. But this battery simply outperformed the others in its category. The rugged, yellow-accented exterior is a refreshing change from the standard shiny black of many tech accessories. It also has a rubberized finish and feels solid enough to handle the bumps and jolts of riding around in a purse or messenger bag all day. It gave both the iPhone and the Galaxy one and a half charges, which means it’s plenty capable of reviving a dead phone a couple of times when you’re out and about.
The Nimble Champ gets an honorary mention here because it’ll also deliver a few reliable fill-ups and comes in a rugged package. It delivered a full charge to the iPhone in two hours plus 22 percent more in 16 minutes. It gave the Galaxy a full charge in an hour and 37 minutes, then got the phone from dead to 41 percent in 50 minutes. At the same $60 price point as the BioLite, Nimble gets extra points for being one of the few B-Corp-certified personal tech manufacturers out there, meaning they’ve committed themselves to higher environmental and social standards, and took the time to prove it through B Lab’s certification process.
- Rugged build
- Plenty of charge in a compact size
Photo by Amy Skorheim / Engadget
Capacity: 15,000mAh, 18W max | Ports: One in/out USB-C, one in/out USB-A | Cable: USB-C to USB-A | Number of charges iPhone 14 Plus: 2.33 | Charge time iPhone: 0 to 100% in 2h 2m average, and 0% to 33% in 27m | Number of charges Galaxy S22 Ultra: 2.33 | Charge time Galaxy: 0 to 100% in 1h 35m and 0 to 37% in 33m | Number of charges iPad Air: 1.31 | Charge time iPad: 0 to 100% in 2h 23m and 0% to 31% in 38m
At the medium-capacity level, you can charge multiple devices at once or power up something larger than a phone. The Otterbox Fast Charge power bank only lists 15,000mAh of capacity, but it performed nearly as well as the 20,000mAh batteries while costing about $30 less. Over the month and a half I spent testing battery packs, this was the unit I grabbed the most when my own devices dropped to empty. It has a stylish exterior with a gray faux leather finish and copper detailing. A little bigger than a deck of cards and weighing just over 11 ounces, it’s a nice looking accessory that feels solid.
It filled up both smartphones twice, then replenished each an additional third. I introduced the iPad to the mix here and got a full charge plus an extra third. The Otterbox also lost very little battery power while sitting dormant, which means if you carry it around on the off chance that you’ll need it, it should have plenty of power when the time comes.
- Attractive design
- Solid build
- Great capacity for the price
- Doesn’t charge as quickly as others in its range
Photo by Amy Skorheim / Engadget
Capacity: 20,000mAh, 65W | Ports: Two USB-C in/out | Cable: USB-C to USB-C | Number of charges iPhone 11: 2.95 | Charge time iPhone: 5 to 100% in 1h 39m average | Number of charges Galaxy S22 Ultra: 2.99 | Charge time Galaxy: 5 to 100% in 59m average | Number of charges iPad Air: 1.83 | Charge time iPad: 5 to 100% in 1h 55m and 83% in 1h 21m
Nimble’s Champ Pro battery delivers a screaming fast charge and got a Galaxy S23 Ultra from five percent to full in under an hour. That’s faster than every other battery I tested except for Anker’s 737, our high capacity pick — and that model costs $30 more. It lent nearly three full charges to both an iPhone and Galaxy device and has enough juice to refill an iPad more than once. The battery pack itself also re-ups from the wall noticeably faster than other models, so it’ll get you out the door quicker.
The company, Nimble, is a certified B-Corp, meaning they aim for higher environmental and social standards and verify their efforts through independent testing. The Champ Pro uses 90 percent post-consumer plastic and comes in packaging made from paper scrap with a bag for shipping back your old battery (or other tech) for recycling.
The unit itself feels sturdy and has a compact shape that’s a little narrower than a smartphone and about as long. The attached adjustable lanyard is cute, if a little superfluous, and the marbled effect from the recycled plastics give it a nice aesthetic. You can charge devices from both USB-C ports simultaneously, and both are input/output plugs.
My only qualm was with the four indicator lights. On a second testing round, it dropped down to just one remaining pip, yet went on to deliver a full fill-up plus an additional top off after that. That said, I’m glad the indicator lights under-estimated the remaining charge rather than the other way around, and the accuracy seemed to improve after subsequent depletions and refills.
- Super fast charging
- Made from recycled materials
- Sturdy and compact design
- Indicator lights underestimate charge
Anker
Capacity: 25,600mAh, 60W max | Ports: One in/out USB-C, two out only USB-A | Cable: USB-C to USB-C, includes 65W wall adapter | Number of charges iPhone 14 Plus: 3.67 | Charge time iPhone: 0 to 100% in 1h 38m average and 0 to 67% in 40m | Number of charges Galaxy S22 Ultra: 3.93 | Charge time Galaxy: 0 to 100% in 57m average 0 to 93% in 59m | Number of charges iPad Air: 2.14 | Charge time iPad: 0 to 100% in 2h 7m average and 0 to 14% in 13m
If you want something with a lot of charge that transfers quickly, go for the Anker PowerCore III Elite 26K. It was for the most part the fastest bank we tried, capable of delivering the largest amount of charge in the shortest period of time for the iPad and Galaxy. The 737 fully charged our S22 Ultra three times, with enough power left over for another 93 percent charge – and those full charges completed in under an hour on average. That’s on par with wall charging. The numbers for the iPhone were slightly less staggering, but still impressive, going from zero to full in about an hour and a half. The iPad charged completely twice, and did so in just over two hours, which is also close to that device’s wall-connected charge speeds.
While it’s great for multiple full charges on a given smartphone, I should point out that the 737 has three ports, but only one of those provides USB-C charging. If you want to charge more than one device at a time, you’ll have to use the lower-efficiency USB-A ports for a couple of them. That said, this bank not only costs less than the other high capacity batteries we tried, it also includes a 65W PowerPort fast charger, which goes for $34 on its own.
The design is nothing groundbreaking, with a glossy black exterior and a metallic-looking finish on one side. It weighs a little over a pound and has the same general form as an old school TI-85 graphing calculator. Its single button has eight lighted pips to show you how much charge it has left.
- Fastest recharge speeds in our tests
- Enough capacity for multiple phone or tablet refills
Photo by Amy Skorheim / Engadget
Capacity: 27,000mAh, 140W max | Ports: One USB-C in/out, one USB-C out, USB-A, 100W AC | Cable: USB-C to USB-C | Number of charges iPhone 11: 3.75 | Charge time iPhone: 0 to 100% in 1h 40m average and 75% in 46m | Number of charges iPad Air: 2.15 | Charge time iPad: 0 to 100% in 1h 56m and 15% in 19m | Number of charges 16” MacBook Pro: 0.65 | Charge time MBP: 10% to 75% in 1h 29m
The TSA’s 100-watt-hour battery limit translates to around 27,000mAh for lithium ion batteries. Mophie’s Powerstation Pro AC is so massive it necessitates a grab handle and get close to the edge of that max carry-on size. You probably won’t find a larger, acceptable portable power bank — after all, an on-the-go charging brick is pointless if you can’t travel with it. I took this one through security at two airports and no one gave it a second glance.
To power your mobile work setup, the Powerstation has four ports. Three of them are the usual USBs, but there’s also a three-prong AC outlet. Most current devices charge via USB (and doing so is more efficient than using a power adapter between the cable and power bank), but older devices and certain mobile workstation accessories — speakers, lights and printers come to mind — might only power up through a basic wall plug. Just be sure to hold down the status button until the light turns red to turn on the AC port.
The AC plug powered most small appliances I plugged into it, including a small speaker, an HP printer and various LED lights. The 100 available watts isn’t enough to continuously push a charge through the 140W power adapter that ships with the 16-inch MacBook Pro, but via the USB-C port, it was able to charge that laptop from 10 percent to 75 percent in under 90 minutes.
The four lighted LED indicators will tell you when the battery is full. Unfortunately, it’s not the best indicator of when the bank will run out of juice. It charges for quite a while with four and three pips lit up, but then quickly cycles through the last two dots before it dies. So it might be better to just remember how much you’ve used the brick rather than relying too heavily on its indicators.
Smaller devices like a smartphone will get numerous charges; I got nearly five refills on an iPhone 11, and two charges and some change on an iPad. The Powerstation Pro AC was even a little faster at both tasks than our previous pick for a mobile command center. That said, this bank is overkill for a simple mobile device fill-up. At 2.6 pounds, it makes the most sense as a power source when you’re working in the field with multiple components.
The Zendure Supertank Pro is also a great pick. It’s slightly smaller at 26800mAh but has a lighted LED display that indicates exactly how much charge remains and how much you’re using. It has four variable-wattage USB-C ports, a tough exterior and comes with a semi-hard case.
- Massive capacity
- Unique AC outlet
Photo by Amy Skorheim / Engadget
Capacity: 20,000mAh, 200W max | Ports: Two USB-C in/out, one USB-A, charging pins | Cable: USB-C to USB-C | Number of charges iPhone 11: 3.75 | Charge time iPhone: 0 to 100% in 1h 48m average and 75% in 47m | Number of charges iPad Air: 1.54 | Charge time iPad: 0 to 100% in 2h 11m and 54% in 47m
Not only does Anker’s new 20,000mAh Prime power bank look pretty slick, it’s also easier to recharge — as long as you pony up for the companion base. Magnets help align the pins so you can just plonk the battery down and move on with your life. The set will run you $200, which is pretty spendy for a battery bank, but if you consider that the base offers extra ports (one USB-A and two USB-C), you can also use it as a power hub for other devices, which takes some of the sting out of the price.
The battery itself has the same three ports as the base and a blocky, upright design. The case is a textured metallic plastic with a high-polish, built-in screen and rounded corners. It tells you how many watts are flowing out to each device and displays the overall remaining charge within the battery. When you press the power button, it takes a moment to wake. But the extra processes that run the screen don’t seem to slow the battery down or diminish the power it has to give. Its charge times and capacity was on par with the other 20K batteries I’ve tested.
I’ve been pretty careful with my review unit, but I’d be worried that the sleek and shiny finish will get wrecked with regular use. It does come with a faux-suede pouch to carry it in, but I doubt anyone will use that regularly — after all, the whole appeal of the Prime’s base and battery set is the low-hassle efficiency.
- Convenient charging with the base
- Sleek, attractive design
- Has a charge indicator display
- Expensive, especially with the base
- Shiny screen seems easily scratched
Photo by Amy Skorheim / Engadget
Capacity: 15,000mAh, 32W max | Ports: One USB-C in/out, one USB-C in, one USB-A | Cable: USB-A to USB-C | Number of charges iPhone 11: 2.99 | Charge time iPhone 11: 0 to 100% 2h average and 0 to 99% in 1h 45m | Number of charges iPad Air: 1.17 | Charge time iPad: 0 to 100% 2h 23m and 0 to 17% 15m
Plenty of battery packs are built to withstand drops and other abuse, but very few are waterproof or even water resistance. It makes sense; water and electrical charges aren’t good companions. The Nestout Portable Charger battery has an IP67 rating, which means it can handle being submerged in water for a number of minutes, and Nestout claims a 30-minute dunk in a meter of water shouldn’t interfere with the battery’s operation. I couldn’t think of a likely scenario where a power bank would spend a half hour in three feet of water, but I could see a backpacker traversing a river and submerging their pack for a few minutes, or a sudden downpour drenching all of their gear. So I tested by dropping the battery in a five gallon bucket of water for five minutes. After drying it off, the unit performed as if it had never been wet.
The water resistance comes courtesy of screw-on caps with silicone gaskets that physically keep the water out, so you’ll need to make sure you tighten (but don’t over tighten) the caps whenever you think wetness is in your future. The company also claims the battery lives up to a military-standard shock/drop specification which sounds impressive, but it’s hard to pin down what exactly that means. I figured it should at minimum survive repeated drops from chest height onto a hard surface, and it did.
As for charging speeds, it wasn’t quite as quick as our recommendation for a mid-capacity bank. The Otterbox charged an iPhone 14 Plus to 80 percent in about an hour and the Nestout got the smaller iPhone 11 to 80 percent in the same amount of time. Another thing to note is that the supplied cable is short, just seven inches total, so you’ll likely want to use your own cord.
Nestout also makes accessories for its batteries, which I found delightful. A dimmable LED worklight snaps on to the top of the battery while a small tripod holds them both up. The portable solar panel reminded me of a baby version of Biolite’s camping panels. Nestout’s version refilled the 15,000mAh bank to 40 percent in under three hours, which sounds slow, but is actually fairly impressive considering the compact size of the panels. This is also a blazingly hot summer, so I’d expect better performance in more reasonable weather.
- Waterproof with the caps secured
- Clever accessories (sold separately)
- Survived drop tests
- Not the fastest charge times
- Included cable is short
Other power banks we tested
Baseus Blade 2
The Blade 2 from Baseus has a unique, flat shape that’s just a little wider than an ereader — which may make it easier to slip into a low profile laptop bag. It charged a Samsung Galaxy S23 Ultra considerably faster than any other battery bank we tried, getting it from four percent to full in just over an hour. It then filled the phone back to 62 percent from dead on a second charge in about a half an hour. But $100 is a lot for a standard power bank that holds fewer than two full charges. But if you can find the Blade 2 on sale, snap it up.
Anker MagGo (6.6K)
Anker’s 6.6k MagGo is pretty similar to our top pick for a MagSafe-compatible battery pack. It supports the Qi2 charging standard and props up your iPhone so you can use it or enable StandBy mode while powering up. This one even lets you set the viewing angle from 30 to 65 degrees. It was speedy in getting an iPhone 15 up to 50 percent in about 40 minutes. But for the added bulk, it doesn’t have as much capacity as the 10K MagGo, holding just enough juice for a single full charge plus about 5 percent. But it is $20 cheaper, which may be key for some.
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