In 2024, nearly every gadget and gizmo that we use has a battery. Our phones are the primary example, but nearly everything — from headlamps to headphones — has built-in rechargeable batteries. As a result of our rechargeable world, portable power banks have become a standard part of everyday life.

　　Power banks offer convenient on-the-go charging when traveling eliminating the need to hunt down an outlet. For outdoor enthusiasts, compact power banks go along on every camping trip, thru-hike, and bike-packing journey.

　　In recent years, power banks have improved exponentially. As we all grow increasingly reliant on our electronic devices, they have become smaller, lighter, and more capable than ever before.

　　To compile this list of the best power banks, we combed the market for the most popular, innovative, and well-regarded models — and then conducted extensive testing at home and in the field to determine the best model for every need and budget. We charged phones, cameras, laptops, and even other power banks.

　　We dropped and lightly abused over a dozen models to determine durability and longevity. In the end, we were left with a clear understanding of which models are worth their weight and price tag. These are the best power banks on the market today.

　　To learn more about what to look for when purchasing a power bank and our rigorous testing process, check out our comprehensive buyers guide, comparison chart, and FAQ sections below.

　　Editors Note: On April 30, 2024, we updated this article by adding another product to the lineup: the InfinityLab InstantGo 10000 Built-in Lightning Cable, a sustainably made option for your on-the-go charging needs.

　　The Best Power Banks of 2024 Best Overall Power Bank: Nitecore NB10000 Gen II Best Budget Power Bank: Charmast 10400 mAh Power Bank Best Power Bank for Laptops and Larger Devices: Goal Zero Sherpa 100PD Most Durable Power Bank: Dark Energy Poseidon Pro 10200 Most Portable Power Bank: Goal Zero Flip 24 Best Size-to-Capacity Ratio Power Bank: Anker PowerCore III Elite Best Magnetic Cordless Power Bank: Hinovo Magnetic Charger Best Overall Power Bank Nitecore NB10000 Gen II Specs Capacity 10,000 mAh Weight 5.29 oz Size 4.8 x 2.32 x 0.42 Inputs USB-C Outputs USB-A (1x), USB-C (1x) Included cables USB-C to USB-C

　　Pros Impact-resistant and generally durable Lightweight with a thin profile Charges quickly Low-power setting for sensitive devices Cons Imprecise battery life indicator lights Austin Beck-Doss Now in its second generation, the Nitecore NB100000 ($60) is a lightweight, no-frills power bank that seriously impressed during testing. This minuscule unit is one of the smallest 10,000 mAh banks on the market. It fits easily in any pocket, and it weighs just over 5 ounces — excellent stats for a power bank that fully charged an iPhone 13 to 100% two and a half times — exactly as the brand claims.

　　The NB10000 isnt the most heavy-duty or luxurious power bank on the market, but it simply performs well in every category without any major flaws or weaknesses. Sure, the battery power indicator light isnt the most precise, but thats a nit-picky criticism in a compact power bank. Ultimately, the NB10000 provides reliable portable power for charging small devices.

　　Our 2-foot drop test didnt leave a scratch on the Nitecores carbon fiber exterior, so we especially recommend this power bank for outdoor use. Its light and packable enough for ultralight thru-hiking, and it contains enough power to keep a phone charged for quite a long time — depending on phone use, of course.

　　Compared to the first generation of the NB10000, the second generation offers increased USB-C output for faster charging. It also has a low current mode, which is useful for sensitive devices with small batteries such as smart watches and Bluetooth earbuds.

　　If you need to charge two devices at once — the Nitecore NB10000 has you covered. Additionally, it has pass-through charging, which allows users to tap into the NB10000s outputs while it is plugged into a wall outlet.

　　$60 at Amazon Best Budget Power Bank Charmast 10400 mAh Power Bank Specs Capacity 10,000 mAh Weight 6.6 oz Size 3.56 x 2.44 x 0.87 Outputs USB-A (2x), USB-C (1x) Inputs Micro USB, USB-C Included cables USB-A to USC-C, USB-A to micro USB

　　Pros Versatile charging configuration Good value Compact The power bank itself recharges quickly Cons Heavy for a 10k mAh power bank Austin Beck-Doss For $22, the pocket-sized Charmast 10400 power bank is an excellent, affordable option for recharging small devices around the house and during weekend getaways. Sure, there are less expensive power banks of this size on the internet, but this one actually works and has great quality for the price.

　　With two USB-A outputs plus an in/out USB-C and a micro USB output, this Charmast works with all sorts of cables. It can theoretically charge up to three devices at a time, though it will drain very quickly under that kind of strain.

　　During our testing, it delivered power to headphones, smartphones, and smartwatches in a timely fashion. It pumped an iPhone 13 from 0 to 100% and again from 0 to 92% in a single full charge. Compared to similarly-sized power banks, the Charmast reloads quickly when plugged into a wall outlet with its included cable.

　　Though the Charmast 10400 power bank is a bit bulkier and heavier than our top overall pick, it still fits easily into a pocket without fuss. The plastic casing doesnt boast any listed waterproofing stats, but it held up perfectly well to our drop test with only minor scuffing.

　　$30 at Amazon Best Power Bank for Laptops and Larger Devices Goal Zero Sherpa 100PD Specs Capacity 25,600 mAh Weight 1.5 lbs. Size 7.7 x 3.81 x 1 Outputs Wireless, USB-C (1x) Inputs USB-A (2x), USB-C (1x) Included cables 39 USC-C to USB-C cable

　　Pros Powerful enough for charging laptops and tablets Durable casing Wireless charging Cons Heavy Austin Beck-Doss During our testing for this roundup, we focused primarily on compact pocket-sized power banks in the 10-20k mAH range. Though these small devices are great for charging small devices on the go, they arent suitable for larger devices like laptops.

　　The Goal Zero Sherpa 100PD ($250) is larger than most power banks on this list. It weighs 1.5 pounds, and it wont fit in a pocket. That said, its still relatively compact, and its the perfect choice for airline travel or car camping, especially when a charged-up laptop is essential.

　　Compared to the smaller banks we tested, the Sherpa boasts several significant upgrades. First, it offers wireless charging. Just set a compatible smartphone or another device on the charging pad and itll power up sans cable.

　　A small display screen keeps the user informed on outgoing wattage, remaining battery life, and more. Its far more informative than the standard series of indicator lights that most small power banks have.

　　The Sherpa charged an iPhone 13 from dead to 100% a whopping seven times using a USB-C to USB-C cord. The brand advertised eight full charges, but this figure depends on many variable factors. In any case, the Sherpa is about four times more powerful than most 10k mAh power banks in this regard. Using the wireless charging surface, the phone fully charged in about 100 minutes.

　　The Goal Zero Sherpa 100PD fully charged a MacBook Air over two times before it ran out of steam — more than enough for a weekend of off-grid computing.

　　$200 at REI$200 at Amazon Most Durable Power Bank Dark Energy Poseidon Pro 10200 Specs Capacity 10,000 mAh Weight 9.6 oz. Size 6 x 3.25 x 0.63 Outputs USB-C (1x), USB-A (1x) Inputs USB-C (1x) Included cables 3 USB-C to USB-C cable

　　Pros Extremely durable Built for extreme conditions Waterproof and fully submersible Cons Heavier than other batteries of similar capacity Austin Beck-Doss In terms of durability, the Dark Energy Poseidon Pro ($120) is miles ahead of nearly every other power bank. According to the brand, it can be fully submerged in water for up to 45 minutes, frozen for four weeks, and dropped from 75 feet in the air. Though we didnt test these bold claims exactly, we used and abused the Poseidon Pro for several weeks, dropping it in the snow, tossing it loose into a backpack, and making no attempt to protect it from harm. It continues to look and perform like new.

　　This power banks bulletproof nature does come with a slight weight increase. Its about 3 ounces heavier than other power banks with comparable capacity. Still, thats a small price to pay for reliable power in extreme conditions. If youre heading to the ends of the earth, this is the right power bank to pack.

　　All power inputs and outputs on the Pro are hidden beneath a rugged mini door. A small LED flashlight sits next to the USB-A and USB-C ports. Four battery indicator lights relay the key information that users need.

　　We managed to squeeze two full charges out of the Dark Energy Poseidon Pro with an iPhone 13 — competitive stats in the 10K mAh category.

　　Check Price at Dark Energy Most Portable Power Bank Goal Zero Flip 24 Specs Capacity 6,700 mAh Weight 4.6 oz Size 3.7 x 1.63 x 0.83 Outputs USB-A (1x) Inputs Built-in flip-out USB-A tip Included cables None

　　Pros Light and portable Built-in USB tip adds utility Simple button-free interface Cons Lacks USB-C output Austin Beck-Doss This Goal Zero Flip 24 ($30) is one degree smaller than the common 10K mAh power bank size class. Its about the same size as a 15-pack of gum, and it charged an iPhone 13 twice (almost, 81% on the second charge). Its great value for $30, and it adds valuable peace of mind on long hikes and bike rides.

　　Unlike most power banks on this list, the Flip 24 only has USB-A input and output. Its not surprising for such a small bank, but it might be annoying for folks without a compatible cable. Plus, USB-C charging tends to be faster than USB-A. The Flip 24 will charge your phone slower than most other options on this list.

　　On the plus side, the Flip 24s built-in USB-A stick is quite convenient. It plugs directly into compatible ports and charges right up without a cord. The battery indicator lights light up when the user presses the USB stick, which doubles as a button — product design panache.

　　For phones, earbuds, and smartwatches, the Goal Zero Flip 24 is a nifty little backup battery. If you need to charge larger devices, go with a power bank with greater capacity.

　　$30 at REI$30 at Amazon Best Size-to-Capacity Ratio Power Bank Anker PowerCore III Elite Specs Capacity 25,600 mAh Weight 1.3 lbs Size 7.22 x 3.24 x 0.94 Outputs USB-A (2x), USB-C (1x) Inputs USB-A (1x), USB-C (1x) Included cables USB-C to USB-C

　　Pros Lots of power capacity in a small package Simple design Intuitive single-button interface Cons Expensive Austin Beck-Doss Anker has a solid reputation for simple, long-lasting, and fast-charging power banks. The Anker PowerCore III Elite ($130) boasts an impressive 25,600 mAh of capacity — an excellent figure for a power bank thats only about 7 inches long.

　　Most power bank users can get by with 10K mAH — a perfectly suitable capacity for a weekends worth of phone and earbud charging. The PowerCore III Elite is a major step up — it contains more than double the capacity of most of the power banks on this list. Its potent enough to charge laptops and tablets, and it still manages to fit into most pants pockets.

　　Of course, the extra capacity has to come from somewhere. The PowerCore III weighs 1.3 pounds. Thats a bit heavy for backpacking. Still, compared to similar capacity options like the Goal Zero Sherpa 100PD, the PowerCore is relatively svelte.

　　The PowerCore III fully charged an iPhone 13 just over six times. Anker claims it can charge three devices simultaneously. During testing, it easily charged two smartphones at the same time.

　　The Anker PowerCore III Elite dented easily during our 2-foot drop test, but it went on working without issue. Its a great compact choice for photographers or remote workers on the go.

　　$100 at Amazon Best Magnetic Cordless Power Bank Hinovo Magnetic Charger Specs Capacity 5,000 or 10000 mAh Weight 4.5 oz. (5,000 mAh version) Size 4.09 x 2.75 x 0.35 Output Wireless charging via magnetic connection Input USB-C (1x) Water resistance Unknown Included cables USB-C to USB-C (1)

　　(Photo/Hinovo) Pros Portable and cable free Fully recharges an iPhone Inexpensive Cons Only works with MagSafe compatible smartphones Austin Beck-Doss This compact power bank magnetically adheres to the back of compatible smartphones to deliver power on the go. Instead of waiting while your phone remains plugged into a cable, the Hinovo magnetic power bank ($40) goes where you go. Its fully mobile and highly convenient.

　　Our Editor-in-Chief has been living with the Hinovo for months, and he appreciates its ease of use and straightforward design. The slim 5,000 mAh version immediately doubles a smartphones battery life without much added bulk. The major downside of the Hinovo is that its only compatible with certain phones that are MagSafe compatible.

　　If youre in for a long phone-intensive workday or cross-country Wi-Fi-enabled flight, the Hinovo magnetic power bank provides reliable assurance that your phone will survive the trip.

　　$50 at Amazon Best of the Rest InfinityLab InstantGo 10000 Built-In Lightning Cable Specs Capacity 10,000 mAh Weight 8.2 oz. Size 6” x 3” x 0.6” Inputs USB-A (1x), lightning cable (1x) Outputs USB-A (1x), lightning cable (1x) Included cables None

　　Pros Slim and lightweight Made of 90% recycled plastic Built in lightning cable for speedy charging Cons Pass-through charging did not work Did not hold charge when inactive Expensive compared to power capacity Austin Beck-Doss The InfinityLab InstantGo 10000 Built-in Lightning Cable ($70) power bank is a sustainably made option for your on-the-go charging needs. It also packs a punch while remaining slim and lightweight. Weighing in at just over 8 ounces, the InstantGo has a 10,000 mAh battery capacity and an integrated USB-A lightning cable for rapid charging right when you need it most. InfinityLabs claims that the fully charged bank can charge an iPhone 12 twice, with a 50% charge within 30 minutes using the lightning cable.

　　While testing, the InstantGo hit a few bumps in the road. InfinityLabs claims the InstantGo has “pass-through charging,” which should allow charging off the power bank while charging from a wall outlet; it did not work. Additionally, the InstantGo did not hold its charge while sitting inactive. If you’re planning on using this power bank as a daily backup, it shouldn’t be an issue. However, if you’re like us and you expect banks to hold their charge after sitting for a period of time (say while traveling), you may be disappointed.

　　During our 2-foot drop test, the InstantGo performed with flying colors, handling drops with no scratches or nicks along the way. While the exterior is velvet-smooth, the power bank doesn’t show scratches that appear easily, making this an excellent contender for outdoor pursuits.

　　While the InstantGo includes only USB-A cables and is not equipped with USB-C ports, this power bank excels in day-to-day use for quick charging, compatible with multiple devices. For iPhone 13’s and Androids, check out InfinityLab InstantGo 10000 Built-in USB-C Cable Power Bank.

　　$70 at REI$80 at Amazon UGREEN 145W Power Bank Specs Capacity 25000mAh Weight 1 lb. 2 oz. Size 6.3 x 32. 1.1 Output USB-C (2x), USB-A (1x) Input USB-C Included cables 1 x 100W USB-C to USB-C Cable

　　Pros Excellent value Charges devices quickly Easy-to-res LED indicator Cons A bit heavy and clunky Austin Beck-Doss For $150, its tough to beat the performance and generous capacity of the UGREEN 145W power bank. Offering 25,000 mAh of storage, this battery brick has enough juice to charge three small devices at once.

　　While the UGREEN may be a little hefty for backpacking, its great for road trips and air travel. During testing, we charged two smartphones and a Kindle all at once, and the UGREEN still had over 50% power left over.

　　We like that this simple power bank is free of frivolous features. It serves its purpose perfectly and doesnt pretend to be anything more than a reliable power bank. The easy-to-read LED display allowed us to keep accurate tabs on its battery life. Its rate of power delivery is right up there with the best banks on the market, but the bank itself is fairly low to charge.

　　Unlike many of the smaller banks on this list, the UGREEN 145W power bank is potent enough to support a laptop. It doesnt support Samsung Super Fast Charging, but it seems to thrive when paired with Apple products.

　　$120 at Amazon Otterbox Fast Charge Specs Capcity 10,000 mAh Weight 8.1 oz Size 5.55 x 2.87 x 0.64 Output USB-C (1x), USB-A (1x) Input USB-C (1) Included cables USB-A to USB-C

　　Pros Accurate battery indicator lights Handsome design Cons Only two ports Standard modern charging speeds despite the Fast Charge name Austin Beck-Doss The Otterbox Fast Charge ($35) is available in three sizes: 10k, 15k, and 20k mAh. We tested the 10k version, though all three models have the same design and two-port layout. With just one in/out USB-C and one USB-A put out, its a simple and effective power bank that works best with smartphones and small devices.

　　The Fast Charge moniker sets up high expectations. This power bank fully charged an iPhone 13 from dead to 100% in just over 90 minutes. While this stat is competitive for a small power bank, its about the same as several other top performers on this list. This Otterbox is a reasonably fast-charging product, but its on par with its peers on this list, not necessarily superior.

　　Compared to the more durable options we tested, the Fast Charge has an all-plastic casing that feels a bit delicate and cheap to the touch. It survived our drop test and continued to function, but it just doesnt have the feel of excellent build quality. Still, its a perfectly usable power bank.

　　The 15k version of the Otterbox Fast Charge ($45) is a nice middle ground between common power bank sizes. We expect it could charge a newer iPhone three or four times, a meaningful improvement over the 10k version.

　　$55 at REI$28 at Amazon BioLite Charge 80 PD Powerbank Specs Capacity 20,000 mAh Weight 16.4 oz Size 6.7 x 3.2 x 1 Output USB-C (1x), USB-A (2x) Input USB-C (1x) Included cables USB-A to USB-C

　　Pros Great power-to-weight ratio Durable plastic shell Fast charging capabilities Cons Battery indicator is not super precise Battery indicator doesnt turn off while charging Austin Beck-Doss This unassuming powerhouse came to be one of our testers favorite power banks by accident. After getting his sleek, lightweight Anker charger stolen on a recent climbing trip, the BioLite Charge 80 PD ($80) — his backup bank — found its way into his backpack on several ultralight treks and long road trip adventures.

　　It takes a lot for a power bank weighing over a pound to end up in a backpacking kit, but for super remote excursions where energy efficiency was a must, this thing was a lifesaver for our tester. Despite its 16.4-ounce weight, it can charge a smartphone over 5 times (tested with an iPhone 11), a tablet twice (tested with an iPad Pro), and even a computer once (tested with a MacBook Pro).

　　While you don’t need all these devices on a backpacking trip, this is a welcome power source for road trips, wilderness photo/video shoots, or international travel. And, for those backpacking jaunts that have you off the grid for five days or more, it’s hard to beat the power-to-weight ratio that this delivers.

　　The two USB-A Quick Charge and single USB-C PD ports offer exceptionally fast charging. The bank also only takes 4.5-5 hours to soak up a full charge, which is better than some other models with similar capacity we’ve tried. Its durable plastic shell gives this an indestructible feel, and we haven’t noticed a scratch on it after many miles of rough use.

　　With a 20k mAh capacity, it has the inherent cons of being quite heavy and comparatively large, but is on par with other banks in its category. We do find the battery indicator to be somewhat lacking. It is a bit hard to gauge exactly how much power is left, and we dont like that the light remains on while charging. Some energy could be saved by having it switch off after it’s been plugged in for a second, and it can get annoying at night if it’s not covered up.

　　These slight gripes aside, we think that the BioLite Charge 80 PD delivers reliable power in a packable, durable design. If pure ultralight minimalism is what you’re after, there are better options out there. But, for the adventurer in need of a bit more juice on their excursions for multiple devices, this would be a solid pick.  

　　$80 at REI$80 at Amazon OKZU C10002Y Specs Capacity 10,000 mAh Weight 6.8 oz Size 5.3 x 2.7 x 0.55 Output USB-C (1x), USB-A (2x) Input USB-C (1x) Included cables USB-A to USB-C

　　Pros Very slim profile Good value This unit charges quickly from a wall outlet Cons No pass-through charging Flimsy plastic casing Austin Beck-Doss The ultra-slim 10k OKZU C10002Y power bank ($28) is marketed as a power source for electrically heated outerwear, but it also works perfectly well for all sorts of small electronics. It charged an iPhone 13 to the brims three times before needing a recharge itself — a great showing for a bank that weighs just 6.8 ounces.

　　We found that the C10002Y gets warm to the touch when plugged into the wall, but this is likely just a result of the thin plastic casing — not a major concern. Speaking of the casing, this definitely isnt the most rugged power bank on our list. It feels like one significant chest-height drop onto a hard surface would be the end of it. We held our breath during the 2-foot drop test, and though it did survive, it sustained minor visible damage.

　　Four indicator lights convert battery levels — including one light that turns green when fast mode is engaged. Interestingly, this light turned green while charging an iPhone via the USB-C port, but not when charging earbuds via a USB-A port. It seems there is some kind of sensor in the OKZU that engaged fast-charging mode when the receiving device has a compatible battery. Neat.

　　Generally, the OKZU C10002Y power bank is yet another sweet little unit. Its mega thin, and hardly detectable when sitting snugly in a pocket. Plus, its affordably priced at just $26.

　　$23 at Amazon Lion Trek Portable Solar Generator Specs Capcity 27,000 mAh Weight 2.1 lbs Size 8.54 x 5.47 x 1.57 Outputs USB-A (2x), USB-C (1x), 12V AC (1x) Inputs USB-C (1x) Included cables Wall outlet to USB-C

　　Pros Features an AC outlet for charging larger devices Durable casing Easy-to-read display Cons Heavy Not the most portable Austin Beck-Doss In both size and capacity, the Lion Trek Power Bank ($149) is the largest power bank on this list. At 2.1 pounds and 8.5 inches long, it takes some liberties with its self-described portable nature. Still, this power bank justifies its size with a massive 27,000 mAh of capacity and a handy AC power outlet.

　　Unlike most of the options on this list, the Lion Trek packs enough power for laptops, tablets, and small appliances like lamps, TVs, and coffee grinders. Its the perfect size for a long-term solo road trip — especially when paired with a compatible solar panel.

　　Weve been testing the Lion Trek for several months. Though its a bit too big and inconvenient for airline travel, its been our go-to power bank for car camping. On a single full charge, the Lion Trek recharged an iPhone 13 nine times. It kept a MacBook Air alive for three days of frequent use. According to its display, the Lion Trek only used 5% of its total battery life to fully charge a pair wireless earbuds.

　　For some folks on the go, an AC outlet is a must-have. The Lion Trek is one of the smallest banks to include one. Additionally, the unit houses two USB-A outputs and one in/out USB-C port. For mobile remote workers, the Lion Trek can function as an ultra-compact solution for the solar-powered off-grid lifestyle.

　　Check Price at Lion Energy Power Bank Comparison Chart

　　An assortment of our favorite power banks; (photo/Mike Misselwitz) How We Tested Power Banks Every power bank on this list has earned its place through rigorous hands-on testing in the same real-world scenarios youre likely to face. Recently, our lead tester, Austin Beck-Doss, didnt plug his phone or laptop into a single wall outlet for several months. Instead, he charged his devices exclusively via a power bank.

　　Through daily use and a series of standardized tests at home and in the field, Austin assessed the durability, performance, and capacity of innumerable brands and models. In 2024, we added Katie Davis to the testing team. Shes a knowledgeable outdoor professional with years of gear testing experience under her belt. Thanks to their efforts, the recommended products on this list are the very best money can buy.

　　Power bank brands make lots of lofty claims about capacity, durability, and performance. Instead of simply trusting the statistics written on the side of the packaging, our testers put manufacturer claims to the test. Every product was fully charged to determine exactly how many times it could fully charge an iPhone 13 before depleting. They also measured the total time that each depleted power bank took to recharge once plugged into a wall outlet fully.

　　Our durability test involved prolonged regular use indoors and out, and a standardized drop test. Every bank was dropped exactly 2 feet onto a concrete surface to simulate the classic electronics fumble that we all experience from time to time. Some ceased to function after a single drop. Of course, none of those models made the list.

　　In total, weve pitted over 30 power banks against our testing sequence. As energy storage technology continues to improve and banks get smaller, lighter, and more powerful, well be sure to update this list to ensure that our recommendations represent the best of the best.

　　Charging the Best Overall Nitecore NB10000 Gen II via USB-C in the home office; (photo/Austin Beck-Doss) Buyers Guide: How to Choose a Power Bank For better or worse, most folks today feel a wave of concern when their smartphone battery drops below 20%. Phones, tablets, laptops, and other portable electronics pack a lot of utility — and weve grown reliant on them to conduct our everyday affairs.

　　Power banks are physical stop gaps that prevent dreaded cases of DPS (dead phone syndrome). Whether you forgot to plug in overnight, or youve been traveling all day without access to an outlet, these are a lifeline for you and your portable electronics.

　　These days, they come in all shapes and sizes — from mini units that can dangle from a keychain to 25-pound behemoths. On this list, we focused on the most popular category: personal-use portable power banks. Portable is a subjective term. For this list, we only considered products that weigh about 2 pounds or less and fit easily into any backpack.

　　In this comprehensive buyers guide, we break down everything you need to know about power banks; capacity, charge times, inputs, outputs, solar capability, you name it. Our hope is that by using this guide, youll be able to hone in on the perfect portable one to suit your everyday needs.

　　What Is a Power Bank? A power bank is a rechargeable battery that can transfer power to other electronic devices. It is like a wall outlet that you can take with you. Simply plug in your phone or laptop via a standard USB-A or USB-C cable, and boom, you have instant portable power. People carry them for the same reason remote freight drivers carry extra cans of gasoline: If the main supply runs out, theres extra fuel on board.

　　The Poseidon Pro Power Bank is fully waterproof and extremely durable; (photo/Austin Beck-Doss) Size and Capacity Power banks are available in many sizes. The smallest ones are small enough to fit on a key chain and typically will only deliver a quick hit of power per charge. The largest ones in existence can charge EVs — but those arent exactly portable.

　　Generally, capacity is measured in milliamps per hour, or mAh. This unit indicates how many milliamps of electric current a given power bank can deliver per hour.

　　All smartphone manufacturers utilize different batteries and charging systems. The working capacity of any power bank entirely depends on the device it is charging. Most fully charged smartphones contain 3,000 to 4,000 mAh. That means, on paper, a 10,000 mAh power bank can recharge a smartphone about three times.

　　Most of the products on this list hold around 10,000 mAh — a standard size for recharging small devices like smartphones, Bluetooth headphones, and smartwatches. Though brands often claim their 10,000 mAh power banks can recharge smartphones five, six, or seven times — they rarely live up to those claims.

　　Smartphone batteries are becoming larger and more efficient. In our experience, 10,000 mAh power banks will charge a modern smartphone between two and three times. On this list, the Nitecore NB10000 is the most impressive 10k mAh power bank that we tested. It fully charged an iPhone 13 two and a half times.

　　If you are looking for a charging option for a long backpacking trip, its important to find an appropriate weight-to-capacity ratio for your adventure. Youll also want one that fits comfortably in your backpacking backpack, and doesnt add too much bulk to your kit.

　　The Anker PowerCore III Elite is plenty powerful to charge a laptop; (photo/Austin Beck-Doss) Compact 10k power banks are rightfully popular. They fit easily into most pockets, and they have plenty of capacity to keep a small device or two alive for a few days.

　　The next standard portable size is 20,000 mAh. Not all power banks in the 20k range will have a capacity of exactly 20,000 mAH — thats just a handy benchmark figure. Naturally, 20k power banks are bigger and heavier than their 10k little siblings. Most 20k banks weigh at least one pound and are roughly the size of a small tablet or jumbo candy bar.

　　Though 20k power banks are a bit cumbersome for everyday carry, they offer much more utility. Most banks of this size can fully recharge a smartphone six or more times. Plus, many 20k versions can charge multiple devices at the same time. If youre looking for a product to charge multiple personal devices over the course of a multiday backpacking trip, 20k is your best bet.

　　Power banks above 20k mAh start to get fairly heavy and less portable, but theyre great for folks looking to charge a larger device such as a laptop on the go. If youre searching for a bank that can handle the demands of laptop charging, around 20k mAh is the bare minimum capacity you should consider.

　　On this list, the Goal Zero Sherpa has an impressive capacity of 25,600 mAh. The Lion Trek is another excellent high-capacity option — and it even sports a standard three-prong AC outlet.

　　Charge Times and Fast Charging The best products are quick to store power and equally quick to dispense it. Combined with the appropriate modern charging cable, all of the power banks on this list perform well in this aspect.

　　These days, many devices, including phones, power banks, tablets, and cables, claim to support fast charging. In reality, there is no universal standard for what fast charging really means. Each individual device has specifications that determine how much wattage delivery it can handle. Every element in the charging system — phone, power bank, and cable — plays a role in the rate of power delivery.

　　All batteries operate with a specific voltage and can input and output a maximum amount of current. Fast-charging options can quickly pump more power into the receiving device.

　　For example, early iPhones came with a 5W power adaptor in the box. Those 5W adaptors took over two hours to charge standard smartphones. On this list, the speedy OtterBox Fast Charge delivers 18W power — it can fully charge an iPhone 13 in just over 90 minutes.

　　In general, any charging source that can deliver around 15W or more could be considered fast charging.

　　While fast charging is highly sought after, it can also be a detriment to your long-term battery health. Certain small devices such as headphones and fitness watches have relatively low maximum tolerable power delivery.

　　If you charge a pair of earbuds with a superpowered fast-charging wall port or power bank, it can cause irreversible damage to the battery life of those headphones. Many modern power banks — such as the OKZU C10002Y and the OtterBox Fast Charge — can decrease their output to meet the needs of a small device or fragile battery.

　　To choose the perfect power bank for your personal devices, check the devices USB PD (power delivery) Power Range. For example, if a devices USB PD Power range is 15-27W, pick a bank that delivers power within that range.

　　Charging a Charmast power bank before heading out for the day; (photo/Austin Beck-Doss) How long do power banks last? If treated properly, the power banks on this list should perform reliably for several years. All batteries degrade with time and regular use. Most modern products can be fully charged and discharged about 1,000 times before they no longer function. For most users, this equates to 3-5 years worth of use.

　　What size power bank do I need? All of the power banks on this list are relatively small and portable. The majority of users pick 10,000 mAh power banks, a good choice for recharging a personal smartphone. Compact 10,000 mAh options like the Nitecore NB 10000 offer a nice balance between utility and portability. They fit in a pant pocket, and they pack enough power to keep a smartphone or satellite messenger alive for several days without a wall outlet.

　　If you plan to charge larger devices like a tablet or laptop, we recommend sizing up to the 20,000+ mAh range. These products typically weigh 1-2 pounds and are still compact enough for hiking, traveling, etc. On this list, the Anker PowerCore III Elite has a strong battery that easily recharges a laptop — or multiple small devices at once.

　　The ultra-slim Nitecore NB10000 fits easily into any pocket; (photo/Austin Beck-Doss) Can I bring a power bank on an airplane? Most small portable option can be carried onto an airplane. According to TSA, power banks cannot be kept in checked luggage. Certain airports dont allow passengers to travel with more than 27,000 mAh in total battery storage.

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