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Title: The best laptop power banks for 2024

Date: Wed, 20 Nov 2024 21:01:27 +0000
Link: https://www.engadget.com/computing/accessorie...

Smaller battery packs are great for refiling phones and tablets, but if you
need to keep a laptop juiced up while youΓÇÖre far from an outlet, youΓÇÖll
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 thatΓÇÖs 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 donΓÇÖt 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, youΓÇÖll want something with a high
milliamp-hourΓÇïΓÇï (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 wonΓÇÖt 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 ΓÇö which is the maximum capacity the
TSA will allow for carry-on luggage. (And note that these batteries canΓÇÖt
be checked, regardless of size).

If you want something even bigger than a laptop power bank, and donΓÇÖt need
to fly with it, youΓÇÖll 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
youΓÇÖd 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 bankΓÇÖs listed capacity and the
actual charge delivered.

Ports

Every large power bank IΓÇÖve 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 ΓÇö 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 youΓÇÖve got a device thatΓÇÖs capable of
70W fast charging, such as the new MacBook Air, youΓÇÖd want to opt for the
100W port to get the best charging speeds possible. Note that devices with a
smaller wattage draw wonΓÇÖt 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 laptopΓÇÖs power adapter for a recharge. But
really, the AC port should only be for devices that canΓÇÖt use USB ΓÇö 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 youΓÇÖll 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 youΓÇÖre charging will likely go down,
and of course, the battery is going to drain proportionally to what youΓÇÖre
refilling.

Wireless charging

Just in the last year and a half that IΓÇÖve 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 ΓÇö particularly, in my
experience, when charging Samsung Galaxy phones (though the lack of a
stabilizing magnetic connection like AppleΓÇÖs 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, youΓÇÖre better off sticking to wired
connections.

Design

All power banks are designed to be portable, but thereΓÇÖs 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 youΓÇÖre 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. DonΓÇÖt 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, IΓÇÖve 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 whatΓÇÖs
available. I went for brands IΓÇÖm already familiar with, as well as battery
packs from well-received manufacturers I hadnΓÇÖt 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.

HereΓÇÖs 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 wasnΓÇÖt able to test two of the
batteries I had slated: the HyperJuice 245W and the UGREEN Power Bank
25,000mAh. Once IΓÇÖve had a chance to see how these two perform ΓÇö as well
as any new worthy contenders that hit the market ΓÇö IΓÇÖll 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 didnΓÇÖt 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 ΓÇ£connect to powerΓÇ¥ 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 batteryΓÇÖs 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. ThereΓÇÖs 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 bankΓÇÖs 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 youΓÇÖre 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 ΓÇö
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 wonΓÇÖt 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 canΓÇÖt 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/accessorie...
120040388.html?src=rss

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