The USB-C connection and USB Power Delivery specification bas brought forward the idea of using a USB external battery pack a.k.a a USB powerbank for charging your laptop computer. This is in addition to using these battery packs for charging your smartphones or tablets.
For example, you could be using these battery packs to “stretch out” your laptop’s run-time while you are away from power, something you may be doing while playing a Civilization game on one of the new many-hour long-haul flights for example. Or you could simply charge up a laptop that has a battery that is depleted. It may also be of use where a battery inside the computer is nearing its end-of-life and is not likely to hold enough charge to permit use away from power.
Here, you have to look towards a USB-C PD-compliant battery pack which can put up at least 30 watts. For air travel, the battery pack would have to have the ideal battery capacity of 2600mAh because of air-transport limitations on lithium-ion batteries larger than 2700mAh for this class.
Features worth looking for include some USB-A connections for mobile phones and tablets along with another USB-C Power-Delivery-compliant connection. Having the two USB-C connections can allow you to charge the battery pack up while you are charging your laptop or running it from AC power – no need to carry extra chargers and travel adaptors with you.
This is mostly relevant to 13” laptops, 2-in-1s and similar devices. You may be able to get some more run-time out of larger-screen devices and other USB-C Power-Delivery devices if you don’t really expect to fully top up the battery in your computer.
The Dell XPS 13 in its clamshell and 2-in-1 forms as reviewed and covered extensively on this site can be charged from these battery packs. The Lenovo ThinkPad X1 Carbon or Yoga variants can do this job as can the HP Spectre X2 detachable and the ASUS Zenbook 3. For gaming-grade performance, you can power the Razer Blade from one of these USB-C battery packs.
Mac users can rejoice with all of the USB-C-equipped Apple MacBook family able to he charged or powered from these external battery packs. Chrome OS users also can know that the Google Pixelbook and the Asus Chromebook Flip C302 can work from these same power sources.
The Wikipedia article will list more laptops that can work from a USB-C Power Delivery battery pack and there is a strong likelihood that newer iterations of the abovementioned computers will run from USB-C Power Delivery in this manner.
You may be able to work around the battery-power limit regarding these batteries if you take two or more USB-C PD battery packs that is within the limits but it is best to confirm these limits with your national government’s air-safety Website.