Travel Tech: Chargers, Adapters & Power Banks

Power banks: size, rules, reality

• Sizing: 10,000 mAh recharges a typical phone roughly twice and fits a pocket — the right answer for most travelers. 20,000 mAh earns its weight only for camping, long-haul flights, or multi-device families.
• Airline rules: power banks and spare lithium batteries must travel in your carry-on — never a checked bag. Up to 100 Wh (roughly 27,000 mAh) is broadly allowed without approval; airlines increasingly ask that you not charge from them mid-flight, so top your devices up beforehand.
• The habit that matters: a power bank packed empty is dead weight. Charging it is a perfect night-before task on your trip checklist.

Adapters vs converters (90% only need one of these)

An adapter changes the plug shape. A converter changes the voltage. Modern electronics — phones, laptops, tablets, camera chargers — are dual-voltage (the brick says "100–240V"), so they need only an adapter. The things that aren't dual-voltage are exactly the things you shouldn't pack anyway: hair dryers, curling irons, kettles. One good universal adapter with built-in USB ports charges three devices from a single wall socket — sockets are the scarcest resource in any hotel room.

The one-charger setup

A single GaN wall charger (gallium nitride — smaller and cooler-running than older bricks) with two or three ports replaces every device-specific charger you own. Pair it with: two USB-C cables (one short for the power bank, one 2 m for the hostile-outlet hotel room), whatever legacy cable your one stubborn device still demands, and earbuds. That's the whole kit.

Skip: travel routers (your phone is a hotspot), "international" voltage converters (see above), and a spare of everything. One spare cable, not five.

Related guides

• International Travel Essentials
• Long-Haul Flight Survival Kit
• Carry-On Only: How to Pack a Week in One Bag