Cell 20

A power bank for a laptop, not only a phone. Cell 20 stores 20,000 mAh (74 Wh) and delivers up to 45 W over USB-C, enough to charge most 13–14″ laptops at close to full speed. A small display on the top edge shows the charge left in percent, next to three ports: two USB-C and one USB-A.

We ran a 13″ laptop with a 52 Wh battery down to 10% and charged it from Cell 20: it reached 80% in 1 hr 10 min, with about 40% left in the bank. At 74 Wh it stays under the 100 Wh carry-on limit; what airlines allow is in our guide to power banks on a plane.

Sharing the 45 W

• 45 W is the total: a laptop on its own gets all of it
• Add a phone and the two share the 45 W, so the laptop charges a little slower
• USB-A for older cables, earbuds and a watch charger

Recharging

• 45 W in over USB-C: empty to full in 2 hr with a 45 W or larger charger such as Brick 65
• The percent display tells you what you have before you leave, not four vague dots
• 12.7 oz: a bag item rather than a pocket item

On a plane

Power banks go in the cabin bag, never in checked luggage. To charge a laptop at the full 45 W, use a cable rated for 60 W or more, such as Link USB-C. Covered by our 2-year warranty.