Choose a power bank by the energy it stores and the output your devices need, rather than the mAh figure alone. For a phone-led workday, focus on practical charging capacity and the right ports; for a USB-C laptop, confirm the laptop’s charging requirements, the power bank’s single-port output and the cable rating. If you fly, check the watt-hour rating and your booked airline’s rules before buying.
If maps, calls, photos, messages and work apps keep your phone busy away from sockets, compare usable energy and USB-C output with the weight you are willing to carry. A headline capacity alone cannot tell you how many full charges your particular phone will receive.
Check that your device accepts charging through USB-C, then compare its documented power requirement with the bank’s single-port output and your cable’s rating. If you charge a phone at the same time, check how output is shared between ports.
Look for the watt-hour (Wh) rating and plan to carry the bank in the cabin. Check your airline’s limits on capacity, quantity, storage and in-flight use for each journey; its conditions can be stricter than UK Civil Aviation Authority guidance.
Start with the devices you need to charge during the day. Then compare capacity and output, and add your airline’s rules to the decision if the bank will travel with you.
| Concern | What to check | Who this matters to |
|---|---|---|
| Usable phone energy | Compare the Wh rating where shown, your phone’s battery capacity and any clearly qualified charge estimate. Nominal mAh is not a guaranteed number of charges. | When maps, photos and calls run through a long day, I need enough energy to recharge my phone without carrying more than I can comfortably manage. Around 42% of consumers put usable phone energy first. |
| Laptop or multi-device output | Confirm USB-C charging support and required wattage for the device, then check single-port output, shared output and cable rating. | If my compatible laptop and phone both need power away from a socket, I need to know what each port can deliver while they are connected. Laptop or multi-device output comes first for around 33% of consumers. |
| Flight restrictions | Check the bank’s Wh marking and your booked carrier’s capacity, cabin-storage and in-flight-use rules for both legs of the journey. | Before flying, I want a bank I can pack correctly and carry under my airline’s conditions, even if that narrows my choice. Airline-rule compliance is the primary concern for around 25% of consumers. |
A mAh figure depends on the stated voltage and does not equal the energy delivered to your phone after conversion and charging losses. That makes it a poor promise of a particular number of full charges.
Compare Wh where available. If you convert a stated nominal capacity, use the relevant nominal voltage: Wh equals mAh multiplied by volts, divided by 1,000. Treat advertised charge counts as estimates.
The connector alone does not establish that a laptop can charge from the bank. The laptop, power bank and cable must support the required USB-C Power Delivery arrangement, and output may change when several ports are used.
Check the laptop manufacturer’s charging specification against the bank’s single-port and shared-output figures, then confirm the cable’s power rating.
The UK Civil Aviation Authority says power banks belong in the cabin, not checked luggage, and limits passengers to two. Its guidance says 100Wh to 160Wh requires airline approval and over 160Wh is prohibited in passenger baggage. Carriers may be stricter: Ryanair does not permit power banks exceeding 100Wh, while Emirates prohibits their use to charge devices on board.
Check the booked carrier’s current capacity, storage and use conditions before outbound and return flights rather than assuming approval or in-flight use.
Electrical Safety First advises buying power banks and chargers from reputable retailers. Government product-safety guidance recommends checking relevant markings and recalls; a UKCA or CE mark represents the manufacturer’s claim about applicable requirements, not an independent guarantee.
Check the responsible seller, product identification, instructions and warnings, applicable markings and product-safety recall information. Register the bank if registration is offered.
Anker’s UK range includes phone-focused and higher-output 20,000mAh power banks.
The UGREEN Nexode range includes multi-port models presented for charging laptops, tablets and phones.
Belkin’s portable-charger range includes everyday USB-C banks, multi-port models and higher-output options.
No: UK Civil Aviation Authority passenger guidance says to keep power banks in the cabin and never pack them in checked luggage. Check your airline’s own carriage and storage conditions before travelling.
Check its Wh rating against both UK Civil Aviation Authority guidance and your carrier’s policy. The CAA says 100Wh to 160Wh requires airline approval, over 160Wh is prohibited in passenger baggage, and passengers are limited to two power banks; Ryanair, for example, does not permit power banks exceeding 100Wh.
Check your booked airline before relying on in-flight charging. easyJet says power banks must not be used to charge devices or recharged on board, and Emirates prohibits both uses on its flights. Permission to carry a bank does not, by itself, mean permission to use it.
There is no fixed number from the headline mAh figure alone. When the relevant nominal voltage is known, calculate Wh as mAh multiplied by volts and divided by 1,000, then allow for conversion losses and compare with your phone’s battery capacity. Treat a manufacturer’s charge count as an estimate, not a guaranteed result.
Check the seller, identifiable product details, instructions, relevant safety markings and recall information. Electrical Safety First recommends a reputable retailer, while UK government product-safety guidance advises checking recognised markings and alerts. A UKCA or CE mark expresses the manufacturer’s claim of meeting applicable requirements; it is not a substitute for checking the product and seller.