Best Travel Power Banks: What Actually Survives a Long Weekend

Power bank listings are full of capacity numbers that don't mean what you think they mean. A "20,000mAh" bank rarely delivers anywhere near that in usable phone charges, and quite a few of them won't get through airport security the way you'd expect. This is about what actually keeps you charged on a real trip, not spec-sheet theatre.

What the mAh number doesn't tell you

Voltage conversion losses mean the real-world usable capacity of a power bank is meaningfully lower than the advertised mAh figure — expect to lose roughly 20–30% in practice. More importantly for travel: airline rules cap carry-on power banks at 100Wh without special permission, which is roughly a 27,000mAh bank at typical voltages, though brands rarely print the Wh rating clearly on the box. Before you fly, check the Wh number stamped on the device itself, not just the mAh figure on the packaging.

Best all-rounder: Anker PowerCore 10K

Around £35–45. Compact, reliable, and good for roughly two full phone charges — the kind of power bank you can leave in a daypack or carry through airport security without a second thought. Nothing flashy, which is exactly the point for everyday travel use.

Best for flying light: GP Batteries Powerbank Plus

Around £25–35. A 10,000mAh bank that sits comfortably under the airline 100Wh limit, weighs about 224g, and has three output ports — one USB-C and two USB-A. It's a sensible default if you're packing light and want one bank that covers a phone and a set of earbuds without adding noticeable weight.

Best rugged, outdoor pick: Nestout 15000mAh Outdoor Battery

Around £60–80. Waterproof, dustproof, and shockproof, with pass-through charging so every port doubles as an input. This is the one to buy if you're camping or hiking rather than moving between hotels — for a standard city trip, it's genuinely more capability than you need.

What actually matters when you're choosing

Match capacity to your trip length, not to the biggest number on the shelf — a bank sized for a week-long trek is just dead weight for a weekend in a city. If you're also charging a laptop or tablet, USB-C PD wattage matters far more than the mAh figure; a high-capacity bank with weak output will charge a laptop painfully slowly, if at all. And always check the printed Wh rating before flying, not just the mAh headline number.

Bottom line

For most travellers, the GP Batteries Powerbank Plus is the safest, lightest default that won't cause problems at security. If you want a bit more headroom for longer days away from a plug, the Anker PowerCore 10K is the more established, widely trusted choice. Save the rugged outdoor bank for actual outdoor trips — it's solving a problem most travellers don't have.