Smaller battery packs are great for refiling phones and tablets, but if you need to keep a laptop juiced up while you’re far from an outlet, you’ll need something larger. For this guide, we tested portable chargers with at least a 20,000mAh (74Wh) capacity, but kept the upper limit below 27,000mAh (99Wh), since that’s about the maximum size allowed by the TSA in carry-on luggage. Some laptop power banks sport extra features like wireless charging or an AC plug so you can power small devices such as a travel printer or an LED lamp.
But what all of them have in common is a larger size and higher price tag than standard battery packs. So if you don’t want to play a guessing game, these are the best laptop power banks we tested. Quick Overview Best laptop power bank for travel Lion Energy Eclipse Mag $149 at Lion Energy Best budget laptop power bank Baseus Power Bank, 20000mAh 100W $100 at Amazon Best laptop power bank for the outdoors Goal Zero Sherpa 100AC $250 at Amazon Best laptop power bank with an AC port Mophie Powerstation Pro AC (2023) 27,000mAh battery More options $170 at Amazon $200 at Verizon $200 at Lenovo Table of contents Best laptop power banks for 2024 What to look for in a laptop power bank How we test portable laptop chargers Laptop power bank FAQs Best laptop power banks for 2024 Photo by Amy Skorheim / Engadget Best laptop power bank for travel Lion Energy Eclipse Mag Capacity : 27,000 mAh, 99.
9 Wh | Ports : One USB-C in/out, two USB-A out and three wireless pads | Cable included : USB-C to USB-C and wall adapter | Charge time iPhone 15 : 5 to 100% in 2h 56m (wireless) 5 - 100% 2h 22m (wired) | Remaining charge after iPhone : ~ 81% | Charge time Galaxy S23 Ultra : 5 to 100% in 1h 20m | Remaining charge after S23 Ultra : ~ 77% | Charge time iPad Air : 5 to 100% in 1h 55m | Remaining charge after iPad : ~ 64% | Charge time MacBook Pro : 10% to 89% in 1h 18m Traveling is one of the top reasons people need to use a portable laptop charger — planes, trains, buses and airports aren’t exactly the easiest places to find a power source. Lion Energy’s Eclipse Mag battery pack has a big 27,000 capacity, which is enough to power a laptop through a couple days of use. I also like how its three wireless charging pads cut down on cable chaos, letting you charge a Qi-enabled phone, earbuds case and Apple Watch at the same time.
You certainly could charge all three of those accessories and a laptop at one time, but as with all batteries, that increased drain will quickly empty it and your charge times will slow down quite a bit. From what I’ve seen, the unit works best as an as-needed power supply when you’re out and about, then, after a recharge, it can moonlight as a three-in-one wireless charger in your hotel room. You can even power up the battery while using the wireless pads, making it a sort of travel-ready multi-device charger .
At two pounds, no one would call this light, but the angled corners and narrow design make it feel more compact than other big batteries. There’s no display to tell you how much charge is left, just four lighted pips at one edge, but I found them to provide a fairly accurate estimate. One thing to note is that the wireless watch pad only works with Apple Watches.
Since Pixel watches don’t support wireless charging and Samsung only recommends its own chargers for Galaxy Watches, that's not surprising. The only other drawback is the single USB-C port. The three wireless pads and the two USB-A ports will likely be enough for a days’ work, but one more type-C port would be ideal.
Compared to other 27,000 maAh battery packs, the $149 price tag on the Eclipse Mag is a good deal. Anker’s biggest (27,650 mAh) Anker Prime battery paired with the charging base is also an excellent travel companion. The battery itself has two USB-C and one USB-A ports and a handy display to indicate remaining charge and output.
Plus the base provides two more type-C and one more type-A ports for charging other devices when you’re back at the hotel — and plonking the battery on the base makes for the easiest power bank recharge I've tried. But at $235 for the set, it’s a bit of a luxury buy. Pros Wireless charging is convenient for travel Compact design for such a large battery Delivers a fast, 79 percent charge to a large laptop Cons Heavy No display Could use one more USB-C port $149 at Lion Energy Photo by Amy Skorheim / Engadget Best budget laptop power bank Baseus Power Bank, 20000mAh 100W Capacity : 20,000 mAh, 74 Wh | Ports : Two USB-C in/out and two USB-A out | Cable : USB-C to USB-C | Charge time iPhone 15 : 0 to 100% in 1h 54m | Remaining charge after iPhone : 73% | Charge time Galaxy S23 Ultra : 5 to 100% in 1h 11m | Remaining charge after S23 Ultra : 66% | Charge time iPad Air : 3 to 100% in 2h 13m | Remaining charge after iPad : 42% | Charge time MacBook Pro : 10% to 62% in 1h 6m I hadn’t even heard of Baseus before I started testing products for these guides.
But after reading the many positive reviews, I gave a few of the brand’s offerings a try and have been repeatedly impressed by their value-to-performance ratio. The Baseus Blade is a compact and flat battery that weighs just over a pound. The shape is more tablet-like than the standard block of most power banks, which makes it easier to slide into a backpack or messenger bag alongside a laptop.
The display underestimates the amount of charge left, which is always better than the alternative. When the Blade was down to just one percent, it gave my laptop a few more percentage points before giving up the ghost. It has two USB-C and two USB-A ports along with little feet at the bottom that keep from moving around as you plug cables into it.
The speeds were admirable, clocking in just a few minutes longer than batteries with larger capacities. That’s the main trade off here: At 20,000 mAh, it’s not going to deliver the same amount of charge as a bigger bank. It boosted my 16-inch MacBook Pro from 10 percent to 62 percent, which is about 20 percentage points lower than the bigger batteries could do.
But for $100, it’s still a speedy portable charger with a convenient shape and a good number of ports. Pros Great value Charges devices quickly Sleek design is easy to carry along with your laptop Two USB-C ports Cons Lower capacity than other laptop power banks $100 at Amazon Photo by Amy Skorheim / Engadget Best laptop power bank for the outdoors Goal Zero Sherpa 100AC Capacity : 25,600 mAh, 95Wh | Ports : One USB-C in/out, one USB-C out, one USB-C in, two USB-A, one AC port, one solar input and one wireless pad | Cable : USB-C to USB-C | Charge time iPhone 15 : 0 to 100% in 1h 49m | Remaining charge after iPhone : 83% | Charge time Galaxy S23 Ultra : 5 to 100% in 1h 3m | Remaining charge after S23 Ultra : 77% | Charge time iPad Air : 4 to 100% in 2h 11m | Remaining charge after iPad : 62% | Charge time MacBook Pro : 6% to 72% in 1h 21m Let’s get the bad news out of the way first: Goal Zero’s Sherpa 100AC costs $300. That makes it the most expensive power bank I’ve tested so far.
But it's a high-quality unit that gives you what you pay for. There’s a wireless charging pad up top, three USB-C ports (though one is input only), plus a couple of USB-A ports, an AC port and an 8mm port that can pair up with a Goal Zero solar panel or 12V adapter cable to recharge from your car. There’s even an internal fan to keep everything cool as it deals with all the output and a status display you can turn on or off.
Goal Zero is probably best known for its outdoor-focused power products — power stations for camping, portable solar panels and camping lights, to name a few. The Sherpa has the same rugged/industrial aluminum unibody design, which would make it an ideal productivity companion for field work. I could see this coming in handy for outdoor photo shoots, job-site projects or just snagging some nature-side office hours.
The ability to recharge from a car’s 12V port or even from solar panels is another nice-to-have, but of course, you’ll need extra equipment. In the case of the car charger, that’s another $40, but the solar panels will add another $250 to your mobile set up. If you find yourself working out in the field relatively often you might appreciate the flexibility.
Pros Wireless charging pad and an AC port Can recharge from solar or a car's 12V port (with accessories) Accurate status display Rugged design Cons Very expensive $250 at Amazon Photo by Amy Skorheim / Engadget Best laptop power bank with an AC port Mophie Powerstation Pro AC (2023) 27,000mAh battery Capacity : 27,000mAh, 99.9 Wh | Ports : One USB-C in/out, one USB-C out, USB-A, 100W AC | Cable : USB-C to USB-C | Charge time iPhone 11 : 0 to 100% in 1h 40m | Remaining charge after iPhone : ~ 73% | Charge time iPad : 0 to 100% in 1h 56m | Remaining charge after iPad : ~ 53% | Charge time MBP : 10% to 75% in 1h 29m Mophie’s Powerstation Pro AC is a bit of a beast, weighing over two pounds and hitting the upper limit of the TSA’s 100-watt-hour battery limit (I flew with it twice and never had any issue, though). It even has a handle strap to help lug it around.
There’s one USB-A port and two USB-C connections, one with a lower 20W rating and one that can deliver 60W. Then there’s the AC port. The AC port on any portable charger is a novel thing to have; as mentioned previously, it’s the USB-C port that should power your laptop because it makes no sense to convert a portable battery’s charge twice.
That said, if you need to power a light, a portable printer or some other appliance that only has a standard two-prong plug, this port will come in handy. Just be sure to hold down the status button to enable the AC function. Mophie’s pack has enough juice to give a smartphone three to four charges, fill an iPad twice with a charge left over and it can charge a 16-inch MacBook Pro from 10 percent to 75 percent in under 90 minutes, while in use.
The four lighted LED indicators aren't the best: I found it cycled through the last two dots far quicker than the first two, which might make you think you have more charge left than you actually do. Pros Massive 27,000mAh capacity Has an AC outlet and two USB-C ports Cons Expensive No status display Lighted pips don't accurately indicate remaining charge $170 at Amazon Explore More Buying Options $200 at Verizon $200 at Lenovo What to look for in a laptop power bank Capacity If you just need to keep a smartphone from dying before you can make it home, just about any power bank will do. But if you need to revive multiple devices or the substantial battery of a laptop, you’ll want something with a high milliamp-hour (mAh) capacity.
A power bank capable of delivering enough power to a laptop will have a capacity between 20,000 and 27,000 mAh. Go higher than 27,000mAh and you won’t be able to take it on an airplane, which is why most portable chargers top out around that number. Since the voltage for most portable power banks is around 3.
7 volts, a 27,000mAh battery translates to 99.9 watt hours — which is the maximum capacity the TSA will allow for carry-on luggage. (And note that these batteries can’t be checked, regardless of size).
If you want something even bigger than a laptop power bank, and don’t need to fly with it, you’ll likely want to look into portable power stations. These can be the size of a car battery or larger and can potentially fuel an entire weekend away. Another thing to keep in mind is that the capacity listed in a power bank's specs is not what will be delivered to your devices.
As I mentioned, the capacity of these banks is around 25,000mAh. Even the huge battery on a MacBook Pro has a mAh rating of around 5,000 - 6,000mAh, so you might think you’d get five full charges but in reality, you only get about a single 70-percent charge. The voltage is different (typically 3.
7V for the power bank and 11.4V for a laptop) which makes the watt-hours, or the amount of energy each battery can hold, different (working out to 92Wh for the battery and 72Wh for the laptop). On top of that, in order to feed a charge from a power bank to a laptop, a voltage conversion takes place and that dissipates a decent amount of energy.
Without turning this into a physics lesson, this all means that a power bank with a 25,000mAh (or 92Wh) capacity will typically fill a 5,000mAh (or 72Wh) laptop battery to about 75 percent. In my tests, I averaged about a 60-percent efficiency rate between a power bank’s listed capacity and the actual charge delivered. Ports Every large power bank I’ve tested has at least three USB ports, with a mix of USB-C and USB-A, which should cover nearly any portable device you need to recharge — earbuds, phones, tablets, laptops, you name it.
In addition to the different plug formats, some ports supply power at different wattages. For example, one USB-C port might be rated for 60 watts, while the one next to it is rated for 100 watts. So if you’ve got a device that’s capable of 70W fast charging, such as the new MacBook Air, you’d want to opt for the 100W port to get the best charging speeds possible.
Note that devices with a smaller wattage draw won’t be negatively affected by connecting to ports with high ratings. For example, a Galaxy S24 Ultra, capable of 45W super fast charging, can happily plug into the 100W port. A device will only draw what it can take, regardless of what a port can supply.
Just remember that the port, device and cable need to be at or above the desired wattage rating to achieve maximum charging rates. Some of these larger batteries also have AC ports. It might seem like a natural fit to plug in your laptop’s power adapter for a recharge.
But really, the AC port should only be for devices that can’t use USB — such as a lamp or a printer. Plugging a power adapter into the AC port only wastes energy through conversion. First, the battery converts its DC power to supply the port with AC power, then the power adapter converts that AC power back to DC so your laptop can take it in.
And as you’ll remember from physics class, each time energy is converted, some is lost to heat and other dissipations. Better to cut out the middleman and just send that DC power straight from the battery to the device. Also, you can use more than one port at a time with these devices; just remember that the speed of whatever you’re charging will likely go down, and of course, the battery is going to drain proportionally to what you’re refilling.
Wireless charging Just in the last year and a half that I’ve been testing portable power banks, wireless charging capabilities have noticeably improved. The first few I tried were painfully slow and not worth recommending. Now the wireless pads built into power banks are impressively fast — particularly, in my experience, when charging Samsung Galaxy phones (though the lack of a stabilizing magnetic connection like Apple’s MagSafe means they only work when rested flat on a pad).
Most wireless charging connections can be used while other ports are also being employed, making them convenient for some mobile battlestation setups. Of course, wireless charging is always less efficient than wired, and recharging from an external battery is less efficient in general. If you want to waste as little energy as possible, you’re better off sticking to wired connections.
Design All power banks are designed to be portable, but there’s a big difference between a pocket-friendly 5,000mAh battery and one of these laptop-compatible bruisers. Most of the latter weigh between a pound and a half to two pounds, which is a considerable addition to a backpack. Many of the options listed here have a display to tell you how much charge remains in the battery, which is helpful when you’re trying to judiciously meet out charges to your devices.
If a bank has a wireless connection, the pad is usually on the flat top and any available AC connection is usually at one end. Both may require you to engage those charging methods. Don’t be like me and grumble loudly that you got a bum unit without pressing (and sometimes double pressing) all the buttons first.
How we test portable laptop chargers For the past year and a half, I’ve been testing and using dozens of portable batteries for our other battery guide. Some of those batteries include the higher-capacity power banks you see here. I also got a hold of a few extra banks just for this guide to make sure we covered what’s available.
I went for brands I’m already familiar with, as well as battery packs from well-received manufacturers I hadn’t tried before (like UGREEN and Lion Energy). I only considered banks with at least a 20,000mAh capacity and mostly stuck with those that rated 25,000mAh and higher. Here’s everything we tested: Zendure Supertank Pro Mophie Powerstation Pro XL Mophie Powerstation Pro AC Lion Energy Eclipse Mag Lion Energy Trek Baseus Blade Laptop Anker Prime 27,650mAh Goal Zero Sherpa 100 AC Due to shipping and travel issues, I wasn’t able to test two of the batteries I had slated: the HyperJuice 245W and the UGREEN Power Bank 25,000mAh .
Once I’ve had a chance to see how these two perform — as well as any new worthy contenders that hit the market — I’ll update this guide accordingly. I tested each power bank with an iPhone 15, a Galaxy S23 Ultra, an iPad Air (M1) and a 16-inch MacBook Pro with the M1 Pro chip. Even though these banks can charge multiple devices at once, I refilled one at a time, to make side-by-side comparisons more straightforward.
I drained the batteries of the phones and tablets to between zero and five percent and then didn’t use any device as it refilled. For the MacBook, I let it run down to 10 percent before plugging in the power bank. That's when most laptops give display a “connect to power” warning, as draining any battery to empty will compromise the battery life.
I then used it as one might in a mobile office, with a Bluetooth keyboard and mouse, while connected to Wi-Fi and a VPN. For each test, I noted how long a completely charged battery took to get a device back to full and how much of the battery’s capacity was used up in one charge. I also noted things like portability, apparent durability, helpful features and overall design.
For reference, here are the battery capacities of the devices I used: iPhone 15: 3,349mAh Galaxy S23 Ultra: 4,855mAh iPad Air (5th gen): 7,729mAh 16-inch M1 Pro MacBook Pro: 27,027mAh Laptop power bank FAQs How do laptop power banks differ from phone power banks? The main difference is size. Phone power banks tend to have a capacity ranging from 5,000mAh to 20,000mAh and laptop powerbanks are typically rated between 20,000mAh and 27,000mAh. There’s no official definition, however.
Laptop batteries are simply larger and need a bigger supply of power to give them a meaningful charge. How do you fast charge a power bank? You can charge a power bank exactly as fast as the power bank’s internal mechanisms will allow. Most batteries are limited in how quickly they can accept and deliver a charge to avoid dangerously overheating.
But to make sure you’re charging a bank as quickly as possible, make sure the wall adapter and the USB-C cable you are using have a high wattage rating — using a 5W power brick and a 10W cable will take a lot longer to refill your bank than a 65W wall charger and a 100W cord. What size power bank do I need for a laptop? Look for a power bank with a rating of at least 20,000mAh. Slightly smaller batteries may work, but they won’t deliver a significant charge to your laptop.
How many mAh to charge a laptop? A milliamp hour (mAh) is how much a battery can hold, and most portable batteries list their capacity using mAh. If you get a battery rated at 20,000mAh or above, it should be able to charge your laptop. Using mAh to discuss laptop batteries can be confusing.
Due to differing voltages, you can’t directly compare the mAh ratings of a power bank battery to a laptop battery. Using watt-hours is a better gauge, as that calculation takes voltage into account..
The best laptop power banks for 2024
Smaller battery packs are great for refiling phones and tablets, but if you need to keep a laptop juiced up while you’re far from an outlet, you’ll need something larger. For this guide, we tested portable chargers with at least a 20,000mAh (74Wh) capacity, but kept the upper limit below 27,000mAh (99Wh), since that’s about the maximum size allowed by the TSA in carry-on luggage. Some laptop power banks sport extra features like wireless charging or an AC plug so you can power small devices such as a travel printer or an LED lamp. But what all of them have in common is a larger size and higher price tag than standard battery packs. So if you don’t want to play a guessing game, these are the best laptop power banks we tested. Table of contents Best laptop power banks for 2024 What to look for in a laptop power bank How we test portable laptop chargers Laptop power bank FAQs Best laptop power banks for 2024 What to look for in a laptop power bank Capacity If you just need to keep a smartphone from dying before you can make it home, just about any power bank will do. But if you need to revive multiple devices or the substantial battery of a laptop, you’ll want something with a high milliamp-hour (mAh) capacity. A power bank capable of delivering enough power to a laptop will have a capacity between 20,000 and 27,000 mAh. Go higher than 27,000mAh and you won’t be able to take it on an airplane, which is why most portable chargers top out around that number. Since the voltage for most portable power banks is around 3.7 volts, a 27,000mAh battery translates to 99.9 watt hours — which is the maximum capacity the TSA will allow for carry-on luggage. (And note that these batteries can’t be checked, regardless of size). If you want something even bigger than a laptop power bank, and don’t need to fly with it, you’ll likely want to look into portable power stations. These can be the size of a car battery or larger and can potentially fuel an entire weekend away. Another thing to keep in mind is that the capacity listed in a power bank's specs is not what will be delivered to your devices. As I mentioned, the capacity of these banks is around 25,000mAh. Even the huge battery on a MacBook Pro has a mAh rating of around 5,000 - 6,000mAh, so you might think you’d get five full charges but in reality, you only get about a single 70-percent charge. The voltage is different (typically 3.7V for the power bank and 11.4V for a laptop) which makes the watt-hours, or the amount of energy each battery can hold, different (working out to 92Wh for the battery and 72Wh for the laptop). On top of that, in order to feed a charge from a power bank to a laptop, a voltage conversion takes place and that dissipates a decent amount of energy. Without turning this into a physics lesson, this all means that a power bank with a 25,000mAh (or 92Wh) capacity will typically fill a 5,000mAh (or 72Wh) laptop battery to about 75 percent. In my tests, I averaged about a 60-percent efficiency rate between a power bank’s listed capacity and the actual charge delivered. Ports Every large power bank I’ve tested has at least three USB ports, with a mix of USB-C and USB-A, which should cover nearly any portable device you need to recharge — earbuds, phones, tablets, laptops, you name it. In addition to the different plug formats, some ports supply power at different wattages. For example, one USB-C port might be rated for 60 watts, while the one next to it is rated for 100 watts. So if you’ve got a device that’s capable of 70W fast charging, such as the new MacBook Air, you’d want to opt for the 100W port to get the best charging speeds possible. Note that devices with a smaller wattage draw won’t be negatively affected by connecting to ports with high ratings. For example, a Galaxy S24 Ultra, capable of 45W super fast charging, can happily plug into the 100W port. A device will only draw what it can take, regardless of what a port can supply. Just remember that the port, device and cable need to be at or above the desired wattage rating to achieve maximum charging rates. Some of these larger batteries also have AC ports. It might seem like a natural fit to plug in your laptop’s power adapter for a recharge. But really, the AC port should only be for devices that can’t use USB — such as a lamp or a printer. Plugging a power adapter into the AC port only wastes energy through conversion. First, the battery converts its DC power to supply the port with AC power, then the power adapter converts that AC power back to DC so your laptop can take it in. And as you’ll remember from physics class, each time energy is converted, some is lost to heat and other dissipations. Better to cut out the middleman and just send that DC power straight from the battery to the device. Also, you can use more than one port at a time with these devices; just remember that the speed of whatever you’re charging will likely go down, and of course, the battery is going to drain proportionally to what you’re refilling. Wireless charging Just in the last year and a half that I’ve been testing portable power banks, wireless charging capabilities have noticeably improved. The first few I tried were painfully slow and not worth recommending. Now the wireless pads built into power banks are impressively fast — particularly, in my experience, when charging Samsung Galaxy phones (though the lack of a stabilizing magnetic connection like Apple’s MagSafe means they only work when rested flat on a pad). Most wireless charging connections can be used while other ports are also being employed, making them convenient for some mobile battlestation setups. Of course, wireless charging is always less efficient than wired, and recharging from an external battery is less efficient in general. If you want to waste as little energy as possible, you’re better off sticking to wired connections. Design All power banks are designed to be portable, but there’s a big difference between a pocket-friendly 5,000mAh battery and one of these laptop-compatible bruisers. Most of the latter weigh between a pound and a half to two pounds, which is a considerable addition to a backpack. Many of the options listed here have a display to tell you how much charge remains in the battery, which is helpful when you’re trying to judiciously meet out charges to your devices. If a bank has a wireless connection, the pad is usually on the flat top and any available AC connection is usually at one end. Both may require you to engage those charging methods. Don’t be like me and grumble loudly that you got a bum unit without pressing (and sometimes double pressing) all the buttons first. How we test portable laptop chargers For the past year and a half, I’ve been testing and using dozens of portable batteries for our other battery guide. Some of those batteries include the higher-capacity power banks you see here. I also got a hold of a few extra banks just for this guide to make sure we covered what’s available. I went for brands I’m already familiar with, as well as battery packs from well-received manufacturers I hadn’t tried before (like UGREEN and Lion Energy). I only considered banks with at least a 20,000mAh capacity and mostly stuck with those that rated 25,000mAh and higher. Here’s everything we tested: Zendure Supertank Pro Mophie Powerstation Pro XL Mophie Powerstation Pro AC Lion Energy Eclipse Mag Lion Energy Trek Baseus Blade Laptop Anker Prime 27,650mAh Goal Zero Sherpa 100 AC Due to shipping and travel issues, I wasn’t able to test two of the batteries I had slated: the HyperJuice 245W and the UGREEN Power Bank 25,000mAh. Once I’ve had a chance to see how these two perform — as well as any new worthy contenders that hit the market — I’ll update this guide accordingly. I tested each power bank with an iPhone 15, a Galaxy S23 Ultra, an iPad Air (M1) and a 16-inch MacBook Pro with the M1 Pro chip. Even though these banks can charge multiple devices at once, I refilled one at a time, to make side-by-side comparisons more straightforward. I drained the batteries of the phones and tablets to between zero and five percent and then didn’t use any device as it refilled. For the MacBook, I let it run down to 10 percent before plugging in the power bank. That's when most laptops give display a “connect to power” warning, as draining any battery to empty will compromise the battery life. I then used it as one might in a mobile office, with a Bluetooth keyboard and mouse, while connected to Wi-Fi and a VPN. For each test, I noted how long a completely charged battery took to get a device back to full and how much of the battery’s capacity was used up in one charge. I also noted things like portability, apparent durability, helpful features and overall design. For reference, here are the battery capacities of the devices I used: iPhone 15: 3,349mAh Galaxy S23 Ultra: 4,855mAh iPad Air (5th gen): 7,729mAh 16-inch M1 Pro MacBook Pro: 27,027mAh Laptop power bank FAQs How do laptop power banks differ from phone power banks? The main difference is size. Phone power banks tend to have a capacity ranging from 5,000mAh to 20,000mAh and laptop powerbanks are typically rated between 20,000mAh and 27,000mAh. There’s no official definition, however. Laptop batteries are simply larger and need a bigger supply of power to give them a meaningful charge. How do you fast charge a power bank? You can charge a power bank exactly as fast as the power bank’s internal mechanisms will allow. Most batteries are limited in how quickly they can accept and deliver a charge to avoid dangerously overheating. But to make sure you’re charging a bank as quickly as possible, make sure the wall adapter and the USB-C cable you are using have a high wattage rating — using a 5W power brick and a 10W cable will take a lot longer to refill your bank than a 65W wall charger and a 100W cord. What size power bank do I need for a laptop? Look for a power bank with a rating of at least 20,000mAh. Slightly smaller batteries may work, but they won’t deliver a significant charge to your laptop. How many mAh to charge a laptop? A milliamp hour (mAh) is how much a battery can hold, and most portable batteries list their capacity using mAh. If you get a battery rated at 20,000mAh or above, it should be able to charge your laptop. Using mAh to discuss laptop batteries can be confusing. Due to differing voltages, you can’t directly compare the mAh ratings of a power bank battery to a laptop battery. Using watt-hours is a better gauge, as that calculation takes voltage into account.This article originally appeared on Engadget at https://www.engadget.com/computing/accessories/best-laptop-power-bank-120040388.html?src=rss