Written by Vinson, Cofounder at Chargeasap, with 10 years building and testing portable chargers.
Most power banks are designed for phones. They top up a battery that needs 15 to 20 watts, and they do it fine. But if you have ever tried to charge a laptop from a power bank, you have probably run into the same problem: the laptop barely moves, or worse, it keeps draining even while plugged in.
The reason is simple. A laptop needs far more power than a phone, and most power banks cannot deliver it. In this guide, I will explain exactly what to look for in a power bank for laptops, what the common mistakes are, and which options actually work based on our own testing.
Why Most Power Banks Cannot Charge a Laptop Properly
A standard power bank outputs 5W to 18W. A MacBook Air needs 30W to charge. A MacBook Pro 16-inch needs 140W. The gap is enormous, and it is why so many people buy a power bank, plug in their laptop, and watch the battery percentage barely move.
There are two things that determine whether a power bank can charge a laptop effectively:
1. Output wattage. The power bank must output at least as many watts as the laptop consumes at idle. For a MacBook Air, that is 30W minimum. For a MacBook Pro 14-inch, that is 67W. For a MacBook Pro 16-inch or a high-performance Windows laptop, that is 100W or more. Anything below these thresholds and the laptop will charge slowly or drain while in use.
2. USB Power Delivery (PD) support. Laptops charge via the USB Power Delivery standard. A power bank must support USB-C PD to communicate with the laptop and deliver the correct voltage. Without PD, the power bank defaults to 5V output, which is far too low for a laptop.
What to Look For in a Laptop Power Bank
When choosing a power bank for laptop charging, these are the specifications that matter:
| Spec | Minimum for Laptops | What It Means |
|---|---|---|
| USB-C PD Output | 45W or higher | Must support Power Delivery to charge laptops at all |
| Capacity | 20,000mAh or higher | Enough to fully charge a MacBook Air once or a MacBook Pro 16" to around 50% |
| Recharge speed | 60W input or higher | Determines how quickly the power bank itself recharges from a wall charger |
| Airline safe | Under 100Wh (27,000mAh at 3.7V) | FAA limits carry-on power banks to 100Wh without approval |
The Airline Rule Most People Miss
This catches a lot of travellers off guard. The FAA restricts lithium battery power banks to 100Wh in carry-on luggage without special approval. Power banks cannot go in checked luggage at all.
100Wh translates to roughly 27,000mAh at 3.7V. Our Flash Pro Ultra and Flash Pro Plus are both 25,000mAh, which sits safely under the 100Wh limit and is compliant on all major airlines worldwide. If you see a power bank advertised at 30,000mAh or higher, check the Wh rating before you fly.
Our Recommendation: Flash Pro Ultra
After testing every major laptop power bank on the market, the Chargeasap Flash Pro Ultra is the one I recommend for most laptop users.
It has a 25,000mAh graphene-enhanced battery and can charge up to 6 devices simultaneously. Here is exactly what each port delivers:
- USB-C1 (140W, PD 3.1): Your primary laptop port. Charges a MacBook Pro 16-inch at full speed.
- USB-C2 (100W, PD 3.0): A second full-speed laptop port, or fast charge a tablet or second device.
- USB-C3 (60W, PD 3.0): For phones, earbuds, or a third device.
- USB-A (60W, QC 3.0): Backwards-compatible fast charging for older devices.
- Wireless pad (15W MagSafe / QI2): Snap your iPhone on and charge it without a cable.
- Watch charger (built-in): Charges both Apple Watch (5W) and Samsung Watch (3W) wirelessly. No separate puck needed.
What separates it from every competitor is the OLED display. Instead of guessing how much charge is left from a row of blinking LEDs, the screen shows exact battery percentage, live wattage output, and estimated time remaining. When you are relying on it for a long flight or a full day of work, that information matters.
We raised $410,539 from almost 2,000 backers on Kickstarter to build the Flash Pro Ultra, which tells you the demand for a genuinely capable laptop power bank was real and underserved.
"I use this daily to charge my MacBook Pro and iPhone on the go. The OLED screen is a game changer. I always know exactly how much charge I have left and how fast it is going out. Nothing else I have tried comes close."
- Verified buyer, Australia
How Does Flash Pro Ultra Compare to the Competition?
The two most popular alternatives people consider are the Anker 737 Power Bank and the Baseus Blade 2. Here is how they stack up against the Flash Pro Ultra on the specs that actually matter for laptop users:
| Flash Pro Ultra | Anker 737 | Baseus Blade 2 | |
|---|---|---|---|
| Capacity | 25,000mAh | 24,000mAh | 20,000mAh |
| Max USB-C output | 140W (PD 3.1) | 140W (PD 3.1) | 100W (PD 3.0) |
| Number of ports | 6 (3x USB-C, 1x USB-A, MagSafe, Watch) | 3 (2x USB-C, 1x USB-A) | 3 (2x USB-C, 1x USB-A) |
| Wireless charging | Yes - MagSafe 15W (QI2) | No | No |
| Apple Watch charging | Yes (built-in, 5W) | No | No |
| Samsung Watch charging | Yes (built-in, 3W) | No | No |
| Display | OLED (%, watts, time remaining) | LED display (% only) | LED indicator |
| Airline safe | Yes (under 100Wh) | Yes (under 100Wh) | Yes (under 100Wh) |
The Anker 737 matches the Flash Pro Ultra on raw wattage, but it has no wireless charging, no watch charging, and a basic LED display. The Baseus Blade 2 is slim and affordable but tops out at 100W, which is not enough to fast-charge a MacBook Pro 16-inch. The Flash Pro Ultra is the only option in this category that replaces your power bank, your MagSafe pad, and your watch charger in a single device.
How to Recharge a Laptop Power Bank Quickly
A 25,000mAh power bank holds a lot of energy, which means it also takes a long time to recharge if you use the wrong charger. The Flash Pro Ultra accepts up to 140W input, which means it recharges from empty in about 70 minutes when paired with our Zeus 280W GaN Charger. Using a standard 20W phone charger would take over 10 hours.
The rule is simple: match your power bank's input rating to your wall charger's output. The higher the wattage, the faster the recharge.
Shop the full Chargeasap power bank range here.
Vinson is Cofounder at Chargeasap, an Australian charging hardware company that has shipped 13 Kickstarter products to tens of thousands of backers since 2016. He has personally tested every power bank in this guide.
FAQ
Can a power bank charge a laptop?
Yes, but only if the power bank supports USB-C Power Delivery (PD) and outputs enough wattage for your specific laptop. A MacBook Air needs at least 30W. A MacBook Pro 16-inch needs at least 100W to charge while in use, and 140W to charge at full speed.
How many mAh do I need to charge a laptop?
For a MacBook Air (49.9Wh battery), you need at least a 15,000mAh power bank to get a full charge. For a MacBook Pro 16-inch (99.6Wh battery), you need at least 25,000mAh. Keep in mind that power banks lose around 20-30% efficiency during conversion, so a 25,000mAh bank delivers roughly 17,000-18,000mAh of usable energy to your laptop.
Are laptop power banks allowed on planes?
Yes, in carry-on luggage only. The FAA limits power banks to 100Wh (approximately 27,000mAh at 3.7V) without special approval. Power banks cannot go in checked luggage. The Chargeasap Flash Pro Ultra and Flash Pro Plus are both 25,000mAh and are compliant on all major airlines.
What is the best power bank for MacBook Pro?
The Chargeasap Flash Pro Ultra. It outputs 140W via USB-C, which is enough to charge a MacBook Pro 16-inch at full speed. It has a 25,000mAh graphene battery, an OLED display showing exact charge percentage and live wattage, and MagSafe wireless charging for iPhone. It is airline safe and recharges in 70 minutes with a 140W wall charger.
