What Size Power Bank Do I Need for Laptop? 2026 Guide

If you work remotely, travel often, study on campus, or use your laptop away from outlets, you may wonder: what size power bank do I need for laptop charging? The answer depends on your laptop’s battery size, charging wattage, USB-C Power Delivery support, and how many extra hours of runtime you want.

In this guide, we’ll explain how to choose the right laptop power bank, how to estimate runtime, and when a portable power station is the better choice.

Quick Answer

For most laptops, choose a power bank with a capacity of 20,000mAh to 27,000mAh and a 45W to 100W USB-C Power Delivery output. Smaller laptops typically run fine on 45W or 65W, while larger models demand 100W or more. If you're tackling long workdays, gaming, charging multiple devices, or setting up a home backup, a portable power station is a much better solution than a standard power bank.

Why Laptop Power Banks Need More Capacity

Laptops consume significantly more energy than phones. While a standard power bank easily recharges a smartphone several times, laptop batteries are much larger and demand higher wattage.

For context, most phones charge at 20W to 30W, whereas laptops typically require 45W, 65W, 90W, or even 100W. High-performance models need even more. If your power bank falls short on wattage, your laptop might charge painfully slowly, only charge while in sleep mode, or continue draining even while plugged in.

How Much Power Does Your Laptop Need?

To find the right power bank, start by checking your laptop charger. Look for the output rating printed on the power brick, which typically looks like this:

20V⎓3.25A = 65W

20V⎓5A = 100W

If the total wattage isn't listed, you can calculate it using this simple formula:

Watts = Volts × Amps

Your power bank should support at least the wattage your laptop requires. If your device came with a 65W charger, opt for a power bank with at least a 65W USB-C PD output. If it needs 100W, step up to a 100W model.

While some laptops can charge from a lower-wattage power bank, the process will be slow. A 65W laptop might accept a 45W charge while asleep or during light web browsing. However, if you're editing videos, gaming, or running heavy software, the battery will likely drain faster than it charges.

Common Laptop Power Bank Sizes

A 10,000mAh power bank is generally too small for serious laptop charging. While it might offer a quick boost for a lightweight USB-C laptop, it's much better suited for phones and tablets.

A 20,000mAh power bank is a practical starting point. Depending on the battery size and efficiency, it can provide a partial to near-full charge for most ultrabooks. Just make sure it offers at least a 45W or 65W USB-C PD output.

For travel and extended work sessions, a 27,000mAh power bank is ideal. Sitting right around the common 100Wh airline limit, it's one of the largest practical sizes allowed in carry-on luggage. Pair it with a 65W or 100W output for better performance.

How to Estimate Laptop Runtime

To estimate how long a power bank will keep your laptop running, compare the watt-hours (Wh).

Use this basic formula:

Runtime = usable Wh ÷ laptop power use

A laptop typically uses 15W to 25W for light tasks, 30W to 60W for heavier productivity, and significantly more for gaming or creative workloads.

For example, a 20,000mAh power bank stores roughly 74Wh before conversion losses. If your laptop consumes 25W during light work:

74Wh ÷ 25W = Approx. 3 hours

Factoring in conversion losses, your actual runtime will likely be closer to 2 or 2.5 hours.

If your laptop draws 50W during heavier tasks:

74Wh ÷ 50W = Approx. 1.5 hours

After accounting for losses, expect closer to 1 hour of real-world use.

While a 27,000mAh power bank (roughly 100Wh) provides more headroom, it still might not get you through a full workday if you're using a power-hungry machine.

What Size Power Bank Do I Need by Laptop Type?

The ideal power bank size heavily depends on your specific laptop. Smaller devices need less wattage and capacity, while performance models demand robust output and larger energy reserves. Use these general guidelines as a starting point:

• For a small Chromebook or lightweight USB-C laptop, a 20,000mAh power bank with a 45W output is usually plenty for light use.

• For a typical ultrabook, MacBook Air, or thin Windows laptop, a 20,000mAh to 27,000mAh power bank with a 65W output is the sweet spot.

• For a larger productivity laptop, MacBook Pro, or mobile workstation, look for a 27,000mAh capacity paired with a 100W USB-C PD output.

• For gaming laptops, high-performance workstations, or machines with dedicated GPUs, a standard power bank likely won't cut it. These power-hungry laptops require high wattage and perform best when plugged into an AC outlet on a larger portable power station.

When a Power Bank Is Not Enough

Power banks are fantastic for personal electronics and light laptop charging. However, they aren't built to handle extended power outages, long remote workdays, or multi-device setups like monitors, routers, lights, and small appliances.

If you need AC outlets, massive capacity, solar charging, or reliable home backup, a portable power station is the way to go. Depending on the model, a power station can keep your laptop charged while simultaneously running your router, lights, phones, small appliances, and even your refrigerator.

Anker SOLIX Portable Power Stations for Laptop Backup

While a standard power bank is great for quick top-ups on the go, Anker SOLIX portable power stations are a great solution when you need serious capacity, AC output, and solar charging. They easily support laptops, monitors, routers, phones, lights, and home essentials during outages, camping trips, or off-grid remote work.

Anker SOLIX F3800 Portable Power Station

Anker SOLIX F3800 Portable Power Station is built for heavy-duty home and work backup. It features up to 2,400W solar input, an expandable capacity from 3.84kWh to 53.8kWh, 120V/240V dual-voltage output, and 6kW AC output per unit. It can keep laptops, routers, monitors, office equipment, refrigerators, and power tools running during outages or off-grid projects.

Anker SOLIX C2000 Gen 2 Portable Power Station

Anker SOLIX C2000 Gen 2 Portable Power Station is a powerful yet compact option for portable charging and laptop backup. It features an expandable capacity of up to 4kWh, lightning-fast recharging (0 to 80% in just 45 minutes), 2,400W rated power with a 4,000W peak, ultra-low 9W idle power consumption, and a 12V⎓10A car charger output. It's an ideal companion for powering laptops, phones, routers, lights, and small appliances during camping trips or emergency setups.

Anker SOLIX S2000 Portable Power Station

Anker SOLIX S2000 Portable Power Station is ideal for essential backup support. It packs a 2,010Wh capacity, 1,500W AC output, and up to 400W of maximum solar input for efficient off-grid recharging.

Weighing 35.7 lbs (16.2 kg), Anker SOLIX S2000 Portable Power Station for Fridge is highly practical for keeping laptops, phones, lights, routers, and even your refrigerator powered during short outages or remote work sessions.

Conclusion

So, what size power bank do you actually need for your laptop? For most users, a 20,000mAh to 27,000mAh capacity paired with a 45W to 100W USB-C PD output is the most practical range. Smaller laptops can get by with 45W, typical modern laptops usually need 65W, and larger, high-performance machines will require 100W or more.

While capacity is crucial, output wattage, cable quality, and your laptop's real-world power consumption matter just as much. A standard power bank works great for short mobile use, but if you're facing long workdays, power outages, RV trips, camping, or need to charge multiple devices, upgrading to a portable power station is undoubtedly the smarter choice.

FAQ

What size power bank do I need for a laptop?

Most laptop users should look for a 20,000mAh to 27,000mAh power bank equipped with at least a 45W to 100W USB-C PD output.

Is 20,000mAh enough to charge a laptop?

Yes, it can provide a partial or near-full charge for many lightweight laptops. However, the exact results will depend on your laptop's battery size, actual power consumption, and standard conversion losses.

Can a 10,000mAh power bank charge a laptop?

Generally, no. While it might provide a minor battery boost to some lightweight USB-C laptops, a 10,000mAh power bank is much better suited for charging phones and tablets.