Are you tired of seeing low battery warnings when you’re using your laptop? Are you wondering if a power bank can charge a laptop?
I was wondering the same thing so I ran some tests, and what I found out might surprise you.
Can a Power Bank Charge a Laptop?
A power bank can only charge a laptop if both the power bank and the laptop support charging over USB-C, and the power bank has a higher watt output than the laptop’s wall charger.
Most 20,000 mAh or higher capacity power banks that support 65W output over USB-C can charge low-power laptops such as an M1 MacBook Air.
Here’s the thing:
While using a power bank to charge a laptop is possible, it’s not the best option. It’s also very hit and miss, and in some cases, the laptop ends up charging the power bank instead, further draining the laptop’s battery.
Consider a Power Station:
If you really need to charge a laptop while on the go, I recommend a Power Station that supports AC output.
Power stations are pretty chunky and heavy but they’re perfect for camping trips, and they’ll charge your laptop as fast as a regular wall outlet. I like this AIMTOM 42000 mAh Power Station with 100W AC output.
Speaking of power stations, you might like my article about charging a laptop with a solar panel.
Power Banks to Extend Laptop Battery Life:
A power bank is more useful to extend the battery life of your laptop than to charge it. It’s perfect for emergency situations when your laptop’s battery is dying and you need a bit more juice to finish a project.
In other words, the laptop will use the power bank’s battery first, before it starts using its built-in battery, which can give you some extra battery time.
And one more thing:
Even if you turn the laptop completely off so it’s not using any power, the power bank will only slowly charge it. Don’t expect a power bank to fast-charge a laptop because it’s just not nearly as efficient as the laptop’s power adapter.
Now let’s look at the requirements for charging a laptop with a power bank.
Requirements to Charge a Laptop with a Power Bank:
To charge a laptop with a power bank over USB-C it needs to be at least 20,000 mAh or higher. Power banks will a smaller capacity won’t be able to provide enough power output to charge a laptop. Most laptops won’t detect the charge from a 10,000 mAh power bank.
Can a 10,000 mAh Power Bank Charge a Laptop?
In most cases, no. Even if a 10,000 mAh power bank supports power delivery through USB-C, the output won’t be enough to charge a laptop. In most cases, your laptop will show a warning saying the charger does not meet minimum power requirements.
USB-C Power Delivery:
An important point is the power bank has to have a USB-C port that supports power delivery. The reason for that is the USB-C standard can support up to a maximum of 100 Watts of power. You won’t be able to charge a laptop through the regular USB-A ports on a power bank.
Granted, the exact watt output of a power bank over USB-C will depend on its capacity, efficiency, and other factors. Some power banks can output the USB-C maximum of 100 watts, but most only output 60 watts or less.
If your laptop does not support charging over USB-C, you won’t be able to use a power bank to charge it. Also, there are lots of laptops that have a USB-C port but it only supports data transfer. Similarly, many power banks have a USB-C port but it’s only for charging the power bank, and it doesn’t deliver power.
To see if your laptop supports charging over USB-C, look for a power delivery logo next to the port. Thunderbolt ports support power delivery.
Output Meets Laptop Power Requirements:
Another thing you want to look at is the power requirements of your laptop. An easy way to do that is to just look a the included power brick and make note of the wattage. If the power brick supports under 100 watts, you can probably charge the laptop with a power bank.
The power brick will show the maximum pull from your laptop under full load. You can decrease the amount of energy that your laptop requires by toggling battery saving mode and closing any demanding apps or games.
Of course, gaming laptops are out of the question, because they have much higher power requirements. In fact, almost any laptop with a dedicated graphics card will require more than 100 watts.
To charge a gaming laptop you will need a power station, even the best power banks can’t meet the energy requirements of gaming laptops.
Can a Power Bank Charge a MacBook?
A power bank with a USB-C PD of 65 watts can charge an M1 MacBook Air because it only needs 30W to run and charge the battery.
M1 Macs do not have very high power requirements. There are plenty of power banks that can deliver more than enough power to charge an M1 MacBook Air just as fast as a wall outlet.
If you’re looking to buy an M1 MacBook Air, or you already have one, take a look at our best dongles for MacBooks.
Power Bank Efficiency
A quick note here is that power banks lose a lot of power based on their efficiency. For example, if a power bank advertises a 30 Watt output, the real output is likely much less because energy is lost due to efficiency. Budget power banks often have an efficiency rating of 80% or lower.
There’s no way to know exactly how efficient a power bank is without thorough tests because it’s not a feature that is advertised. Nevertheless, in most cases, the mid-range power banks are usually more energy-efficient than the budget options.
To summarize, even if the power bank can deliver enough power for a laptop on paper, the real power output will be quite different.
The Bottom Line:
A high-capacity power bank can charge low-power laptops through USB-C power delivery and extend their battery life. It can be useful when you need some extra juice.
However, if you need something more reliable and that can charge a laptop multiple times, I recommend looking into a power station that supports AC output.
Have you tried charging a laptop with a power bank? Let me know how it worked out in a comment below.