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Buying Guide Power Banks

How to Choose a Power Bank

Quick answer

Pick capacity by how many charges you need, check the output watts for your laptop or phone, stay under 100 Wh if you fly, and buy a known brand to avoid fakes.

By Buyrskip Editorial Team Updated 1 min read

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Capacity in plain terms

A 10,000 mAh bank charges most phones about twice. A 20,000 to 25,000 mAh bank charges a phone four or five times, or a laptop about once. Bigger capacity means more weight, so buy what you will actually carry.

Watts decide speed

  • 20W to 30W: fast charging for phones
    – 45W to 65W: tablets and thin laptops
    – 100W to 140W: larger laptops such as a MacBook Pro

Flying with a power bank

The CAA allows power banks up to 100 Wh in carry-on bags only. Check the Wh number printed on the bank. Most 25,000 mAh models are just under the limit.

Extras worth paying for

  • A built-in cable for everyday carry
    – A display that shows remaining charge
    – Pass-through charging so the bank and phone charge overnight from one outlet

Our picks

See all our best power banks in the uk for more options.

Frequently asked questions

What does mAh mean?

Milliamp-hours measure capacity at the battery's internal voltage. Watt-hours are a better comparison across devices and are what airlines use.

Why does my power bank deliver less than its rating?

Energy is lost converting voltage and as heat, so expect about 60 to 70 percent of the rated capacity to reach your phone.

How long do power banks last?

Most keep good capacity for 300 to 500 full cycles, or about two to three years of regular use.

Buyrskip Editorial Team

Part of the Buyrskip research team. We compare specifications, documentation and real-world trade-offs so you can decide faster.

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