I sat down at an airport gate, opened my laptop, and watched the battery icon flash 4%. The only outlet within 50 feet was occupied by a family charging four devices through a daisy-chained power strip they had apparently brought from home. I bought a $60 power bank at the airport gift shop that charged my phone twice and died.

A good power bank that charges both your phone and your laptop is one of those things you do not think about until you need it — and when you need it, you need it badly. Here is what to look for so you buy one good unit instead of two bad ones.

The Specs That Actually Matter

Power Delivery (PD) 65W minimum. Laptops need more power than phones. A 20W power bank charges your phone fast but will not touch your laptop. Look for USB-C Power Delivery with at least 65W output. 100W is better if you have a larger laptop (15-inch or bigger).

Capacity: 20,000mAh minimum for laptop use. A 10,000mAh bank charges your phone 2-3 times. It might give your laptop 30-50% — useful in a pinch but not a full workday. 26,800mAh is the sweet spot: charges most laptops once fully or your phone 5-6 times, and it is still under the TSA 100Wh limit for carry-on.

Airline Rules You Need to Know

TSA limits power banks to 100 watt-hours (Wh) — roughly 27,000mAh at 3.7V. Anything above that requires airline approval. Most quality laptop power banks advertise their Wh rating clearly. If a bank is over 100Wh and you fly, skip it.

Models Worth Considering

Anker 737 (PowerCore 24K): 24,000mAh, 140W output, charges a MacBook Pro and an iPhone simultaneously at full speed. Digital display shows remaining percentage and charge rate. Heavy at 1.4 pounds but it is a brick that works.

Baseus 65W 20,000mAh: Slimmer and cheaper than the Anker. 65W output handles most ultrabooks (MacBook Air, Dell XPS, ThinkPad). Charges your phone at 18W simultaneously. Good if you want something that fits in a laptop bag without adding noticeable weight.

UGREEN 145W 25,000mAh: 145W total output across three ports. Charges two laptops and a phone at the same time — overkill for one person, useful if you travel with a partner. Digital display, TSA-compliant.

I now carry the Anker 737 in my bag. It has saved me at two airports, one coffee shop with no outlets, and a train where the power sockets were broken. It weighs more than I would like. It works every time.