Q: What's the difference between mAh and wattage on a power bank?

mAh (milliamp-hours) measures how much energy the bank stores ; wattage (W) measures how fast it can deliver that energy . A large-capacity bank with low wattage is like a big fuel tank with a narrow pipe — it holds a lot but charges slowly. For fast charging, you need both: sufficient capacity for your needs and enough wattage to match your device's fast-charge protocol (USB-PD, Quick Charge, etc.).

Q: What capacity power bank is allowed on flights?

Most airlines follow IATA guidelines: power banks up to 100Wh are permitted in hand luggage without restriction ; banks between 100Wh and 160Wh require airline approval; anything above 160Wh is generally prohibited in the cabin. To convert mAh to Wh, multiply mAh by the voltage (typically 3.7V) and divide by 1,000. A 20,000mAh bank at 3.7V = 74Wh — well within limits. A 27,000mAh bank at 3.7V = roughly 100Wh, right on the boundary. Always check with your specific airline before travelling.

Question 1

How many times can a power bank charge my phone?

Accepted Answer

A 10,000mAh power bank will charge a typical modern smartphone (3,500–4,500mAh battery) roughly 1.5 to 2 times, accounting for the 80–90% energy conversion efficiency of most banks. A 20,000mAh unit gets you 3–4 full charges. Keep in mind that wireless charging reduces this further by 10–15% due to heat loss. If you want to be precise, divide the bank's mAh by your phone's battery capacity, then multiply by 0.85 as a realistic efficiency factor.

Question 2

Can a power bank charge a laptop?

Accepted Answer

Yes, but only if it supports USB Power Delivery (USB-C PD) at 65W or higher — and many power banks don't, even if they have a USB-C port. Standard 5V/2A USB-C outputs (10W) will not charge most laptops. For MacBooks and USB-C Windows laptops, look for 65W PD minimum; the Xtorm XB403 Titan Ultra at 200W is the most capable option in our catalogue. Also check your laptop's charging requirements — some ultrabooks accept 45W, while gaming laptops may need 100W+.

Question 3

What's the difference between mAh and wattage on a power bank?

Accepted Answer

mAh (milliamp-hours) measures how much energy the bank stores; wattage (W) measures how fast it can deliver that energy. A large-capacity bank with low wattage is like a big fuel tank with a narrow pipe — it holds a lot but charges slowly. For fast charging, you need both: sufficient capacity for your needs and enough wattage to match your device's fast-charge protocol (USB-PD, Quick Charge, etc.).

Question 4

Are cheap power banks from unknown brands safe to use?

Accepted Answer

Not always — this is the one area where cutting corners genuinely carries risk. Substandard Li-Ion cells can overheat, swell, or in rare cases catch fire. Always check for CE and RoHS certification markings, which are legally required for UK sale. Avoid banks with no brand markings, no certifications listed, or suspiciously high mAh claims for their size (a 30,000mAh bank that weighs 200g is almost certainly mislabelled). Sticking to recognised brands — even budget ones like Intenso or LogiLink — gives you a meaningful safety baseline.

Question 5

Is wireless charging on a power bank worth it?

Accepted Answer

It depends entirely on how you use it. Wireless charging on a portable bank is genuinely convenient for overnight top-ups or in-bag charging with a MagSafe iPhone, but it's slower (typically 10–15W maximum) and less efficient than a cable. If speed matters — say, you have 30 minutes before heading out — plug in. The Varta Mag Pro Wireless and Anker A1664H11 are the most polished wireless options in our catalogue, but neither will replace a fast-wired charge when you're in a hurry.

Question 6

What capacity power bank is allowed on flights?

Accepted Answer

Most airlines follow IATA guidelines: power banks up to 100Wh are permitted in hand luggage without restriction; banks between 100Wh and 160Wh require airline approval; anything above 160Wh is generally prohibited in the cabin. To convert mAh to Wh, multiply mAh by the voltage (typically 3.7V) and divide by 1,000. A 20,000mAh bank at 3.7V = 74Wh — well within limits. A 27,000mAh bank at 3.7V = roughly 100Wh, right on the boundary. Always check with your specific airline before travelling.

Question 7

Should I avoid power banks that claim very high mAh at very low prices?

Accepted Answer

Yes — inflated capacity claims are one of the most common issues in this category. A genuine 20,000mAh Li-Ion bank cannot weigh less than roughly 300g; if a product claims 20,000mAh but weighs 150g, the real capacity is almost certainly far lower. The MediaRange MR756 at 20,000mAh is a legitimate budget option; the truly suspicious products are typically unbranded listings on marketplace sites. If the price is below 9 £ for anything claiming over 10,000mAh, treat it with serious scepticism.

Power Banks Price Comparison

Sandberg Powerbank USB-C PD 130W 50000

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LogiLink PA0273 power bank 10000 mAh Black

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Sandberg Survivor Powerbank 20000

Sandberg Outdoor Solar Powerbank 16000

Sandberg Outdoor Solar Powerbank 24000

DELL PW7018LC power bank Lithium-Ion (Li-Ion) 19200 mAh Silver

Canyon CNS-TPBW8B power bank Lithium Polymer (LiPo) 8000 mAh Wireless charging Black

Sandberg Outdoor Solar Powerbank 10000

Canyon CNE-CPB010B power bank Lithium Polymer (LiPo) 10000 mAh Black

Canyon 20000 mAh, 2x5V max 2.4A (USB), Smart IC technology allowing to charge Lithium-Ion (Li-Ion) White

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Intenso 7313520 power bank Lithium Polymer (LiPo) 5000 mAh Black

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Manhattan Power Bank, 10000 mAh, Output: 2x USB-A (2.1A & 1A), Input: USB-C & Micro-USB (both 2A), White, One Year Warranty, Blister

Belkin BPD002BTBK power bank 2500 mAh Wireless charging Black

Belkin BOOST↑CHARGE 10000 mAh Rose gold

Power Banks Price Comparison