The Ultimate Guide to Laptop Power Banks for 2025
If you travel or work away from an outlet, a laptop power bank is an essential tool. These larger portable chargers hold enough energy to refill a phone multiple times, charge a tablet a couple of times, and can get most laptops from near-dead to work-ready in about an hour. After testing dozens of batteries, here are the best laptop power banks for 2025, along with key information on what to look for and how to fly with them.
Flying with a Laptop Power Bank
Most portable batteries max out around 27,000mAh to comply with TSA regulations for carry-on luggage, which limits capacity to 100 watt-hours. You are never allowed to pack any batteries in checked luggage. Due to recent onboard incidents involving battery fires, some airlines have implemented further restrictions. Carriers like Emirates and Southwest may limit the number of power banks you can bring and require them to be kept in clear view during use if they are actively charging a device. Always check your specific airline’s policies before you fly.
What to Look for in a Laptop Power Bank
Capacity is the most critical factor. While any power bank can charge a phone, you need a high-capacity unit for a laptop. Look for a power bank rated between 20,000 and 27,000 mAh. It is important to understand that the listed capacity is not what will be delivered to your device due to voltage differences and energy loss during conversion. A 25,000mAh bank will typically fill a large laptop battery to about 75 percent.
Pay close attention to the ports. A good laptop power bank will have a mix of USB-C and USB-A ports, with some offering different wattages. For the fastest laptop charging, use a high-wattage USB-C port, such as a 100W output. Ensure your charging cable also supports the high wattage. Some banks include AC outlets, but these are best used for devices that cannot charge via USB, as using them for a laptop adapter wastes energy through unnecessary power conversion.
Wireless charging has improved significantly. Many modern power banks include fast wireless charging pads, which are convenient for phones, though wired charging remains more efficient.
Design and portability are also considerations. These high-capacity banks are not light, typically weighing between 1.5 and 2 pounds. Helpful features include a clear display showing the remaining charge and a logical layout of ports and buttons.
How We Test
We tested numerous power banks with capacities of 20,000mAh and above. Each bank was used to charge an iPhone 15, a Galaxy S23 Ultra, an iPad Air, and a 16-inch MacBook Pro. We measured how long a full charge took for each device and how much of the power bank’s capacity was consumed. We also evaluated portability, design, and overall usability.
Frequently Asked Questions
How do laptop power banks differ from phone power banks?
The main difference is size. Laptop power banks are larger, with capacities typically between 20,000mAh and 27,000mAh, providing the substantial power needed for a laptop.
How do you fast charge a power bank?
To charge a power bank as quickly as possible, use a high-wattage wall adapter and a compatible USB-C cable that meets or exceeds the bank’s maximum input rating.
What size power bank do I need for a laptop?
You need a power bank with a rating of at least 20,000mAh. For a more substantial charge that can refill a large laptop battery significantly, aim for 25,000mAh or higher.
How many mAh does it take to charge a laptop?
While mAh is a common rating, it can be misleading due to voltage differences. A better gauge is watt-hours (Wh). A power bank rated around 92Wh (approximately 25,000mAh) can deliver a meaningful charge to a standard laptop battery.
