Information current as of 03/31/2026.
For most travel, choose a 10,000–20,000 mAh power bank. A 10,000 mAh model suits a typical day trip and one phone user, while 20,000 mAh provides more reserve for several days or for charging a phone plus accessories or a tablet. Check the bank’s watt-hours, carry it in your cabin bag rather than checked baggage, and verify the operating airline’s current rules before departure.
Choose capacity by trip and device mix
A 5,000 mAh bank is best for emergency top-ups, short outings, and minimum weight, but it offers limited reserve. A 10,000 mAh bank is a practical choice for a typical day trip and one phone user. Choose 20,000 mAh for several travel days, frequent phone use, or a phone plus earbuds, camera, or tablet. For a USB-C laptop, do not choose by capacity alone: confirm the bank’s sustained USB-C Power Delivery output and the computer’s charging requirement.
Compare usable energy, not just printed mAh
The advertised mAh rating describes the battery cells, not the amount that reaches your device. Conversion from the battery voltage to USB voltage, circuitry, cables, heat, and charging behavior reduce delivered energy, so a simple mAh-to-mAh comparison overstates the result. Use this formula for stored cell energy: Wh = mAh × nominal battery voltage ÷ 1,000. For example, 20,000 mAh × 3.7 V ÷ 1,000 equals approximately 74 Wh of stored cell energy.
Check airline limits before you fly
Use watt-hours when checking aviation limits because mAh does not express total energy without a voltage assumption. At a nominal 3.7 V, 100 Wh is approximately 27,000 mAh, but the manufacturer’s printed Wh rating takes precedence. IATA traveler guidance identifies power banks up to 100 Wh as generally allowed in carry-on baggage and 100–160 Wh as potentially requiring airline approval. However, IATA’s operator guidance dated 03/31/2026 lists power banks above 100 Wh and up to 160 Wh as forbidden in its passenger power-bank table. Policies can vary by airline, route, and applicable regulations, so check the operating airline’s current policy. Power banks should be packed in cabin or carry-on baggage, not checked baggage.
Match USB-C Power Delivery to your devices
For phones and ordinary accessories, a USB-C power bank with USB Power Delivery is a flexible option. For tablets and laptops, match the bank’s sustained USB-C PD output to the device’s required wattage and confirm that the device and cable support the charging setup. USB PD can negotiate power levels, and USB PD Revision 3.1 supports applications up to 240 W with suitable USB-C equipment. Cable capability matters as well: USB-IF identifies 60 W and 240 W USB-C to USB-C cable labeling categories. A high wattage printed on the power bank does not by itself guarantee compatibility.
Practical buying checklist
Before buying, confirm: the capacity in mAh; the manufacturer’s Wh rating; whether the size and weight fit your trip; the device mix you need to charge; sustained USB-C PD output for any tablet or laptop; suitable cable power labeling; and the operating airline’s current carry-on rules. For a general-purpose travel choice, start with 10,000 mAh for lighter day trips or 20,000 mAh when you need more reserve, then verify the Wh rating rather than relying on mAh alone.