PowerBankExpert.com is reader-supported. If you purchase products via the links on our site, we might earn affiliate commissions.

How to charge your power bank using a laptop

How to charge your power bank using a laptop

While a power bank is usually used to charge other devices, there are times when it runs out of juice, and you consider charging it using another device, such as a laptop. For example, this situation may occur if you forget to carry the power bank’s wall charger and cable or without access to a wall outlet and prefer to have power in your power bank rather than in your laptop. So, without further ado, let’s see how it’s done.

Charge the power bank with the laptop charger

If you’ve forgotten your power bank’s wall charger and cable, you can still charge it using the laptop charger. However, the two must share two features: a USB-C port and a charging protocol—most gadgets, including laptops and power banks, feature USB-C ports, and for a good reason. Aside from fast data transfer, USB-C provides a high power supply and a secure way to connect peripherals to the computer. Along with these practical advantages, USB-C ports’ reversible design makes them more user-friendly.

However, simply because two devices share the same port name and design does not indicate they are compatible. Apart from the port type, the charging protocol is essential. While USB-C has a number of advantages, it looks as though it was insufficient since manufacturers have included a charging protocol called Power Delivery.

At the moment, most products having a USB-C connector also support this charging protocol. Therefore, if your laptop has this function, it means that its charger is capable of delivering a range of output voltages. The following requirement for properly charging the power bank is that the input port of the power bank supports USB-PD as well.

This is how the Power Delivery protocol works: the port and the charger exchange information about the maximum input voltage and current that the port can handle. The charger then delivers the power bank with the agreed-upon voltage and current to avoid any damage.

It’s worth noting that, in addition to the Power Delivery charging protocol, which prevents the charger from sending excessive voltage and current that might damage the power bank, both the power bank and the battery within include protective features. These intelligent circuits safeguard the power bank against over-current, over-voltage, and overcharge. As a result, there is no need to be concerned, as two protocols are in charge of safely charging the power bank via the laptop’s charger.

Besides the safety aspect, because the outcome of the conversation between the charger and power bank is the maximum voltage and amperage that the port is capable of taking, you will have the safest and fastest charging speed possible. Thus, it makes no difference whether the laptop charger is 60W or 100W.

Currently, most laptops with USB-C connectors have adapters that deliver 100W; however, Apple just announced a new wall charger for the 16-inch MacBook Pro that delivers 140W. Additionally, the wall charger supports USB-C PD 3.1.

Charge the power bank using the USB slots of the laptop

You have two options when it comes to charging a power bank with a laptop: USB-C or USB-A.

USB-C standards were published in 2014, and in 2018 and 2019, the standard’s adoption in devices increased significantly. Fast forward to late 2021, and USB-C is now found in nearly all devices. So, if you purchased your power bank and laptop recently, they are more likely to include this connector.

We’re starting with USB-C because this connector is capable of handling very high voltage and amperage. On the other hand, charging speed is dependent on these dependent parameters; the greater the voltage and amperage, the faster the charging.

To use the laptop’s USB-C port to charge the power bank, connect the USB-C output port to the power bank’s USB-C input. You should now be able to see the power bank charging through the power bank’s LED indication or display.

Due to the higher voltage and current of USB-C, the power bank will charge more quickly. However, if both ports support Power Delivery, you’ll be able to charge the power bank at the fastest possible speed, which is quite convenient. If you’re unsure whether your power bank or laptop’s port supports this capability, you can check the specs table for both devices in the user manual. If you do not have access to the user manual, you can check the product pages for both items to ensure they have a USB-C PD (USB-PD) port.

Keep in mind that because USB-C charges at a faster rate, the laptop’s battery will drain faster. As a result, you should plug the laptop into the charger if feasible. It’s worth noting that most laptops now include only USB-C output and lack USB-C Power Delivery output. However, the USB-C fast charge will remain a luxury for the time being.

Moreover, if your laptop lacks a USB-C output port or your power bank lacks a USB-C input connector, you can utilize the USB-A port. To charge the power bank using this method, first ensure that it has a USB-A input port. Next, connect the laptop’s USB-A or USB-C output port to the power bank’s USB-A input port to charge it.

The problem with this method is that, in comparison to USB-C, USB-A operates at extremely low voltage and amperage, resulting in a slow charging speed. The USB 1.0 and 2.0 standard ports supply up to 500mA or 0.5A. Also, USB 3.0 can deliver up to 900mA or 0.9A, which equates to 4.5W.   It’s important to note that these power output specs are based on the 5 volts provided by each standard output. 

Note that you are not using a wall charger to charge the power bank, so you are not charging it at its maximum speed. Thus, to quickly charge the power bank, you must completely turn it off. If you utilize the flashlight or any other power bank feature, the charging speed will be slowed. In addition, pass-through charging (charging another device while charging power bank) drastically slows down charging.

Is it safe to charge a power bank with a laptop?

Yes, charging a power bank with a laptop is safe. Because power banks have big lithium batteries, manufacturers have integrated many circuits to keep the battery safe. One voltage regulator is located on the battery, while the other is located on the power bank. The one on the power bank is often unique to each company, and they design it solely as part of their proprietary technology for power bank protection.

Additionally, these technologies safeguard the power bank and its battery from damage caused by over-voltage, over-current, and other hazards. Thus, even if the laptop’s voltage output is extremely high, that technology will cut the connection between the two devices. However, bear in mind that not all manufacturers have incorporated these technologies; consequently, we recommend that you only purchase power banks from reputable brands.