For most holidaymakers, a compact 10,000mAh power bank is the best balance between useful capacity and luggage weight.
Long travel days, sightseeing, family holidays and travellers who rely heavily on their phones
Travellers whose devices comfortably last all day and who are rarely away from charging points
INIU 10,000mAh 45W Power Bank
A strong travel balance of 10,000mAh capacity, fast 45W USB-C charging and compact size without moving into bulky high-capacity territory.
Anker 10,000mAh 30W Power Bank
A good alternative for travellers who prefer an established charging brand and want 10,000mAh capacity with modern USB-C fast charging.
A power bank is one of the easiest travel accessories to justify if you rely heavily on your phone while you’re away.
Maps, boarding passes, hotel apps, translation, photos, messaging and entertainment can all drain a battery much faster than normal. The challenge isn’t deciding whether portable charging is useful. It’s deciding how much battery you actually need without carrying unnecessary weight.
Which? has tested more than 100 power banks from brands including Anker, Belkin, INIU and Samsung, looking at charging speed, usable capacity, features and ease of use. Its testing reinforces an important point: the number printed on the box doesn’t tell you everything about real-world performance.
Our view is:
For most holidaymakers, a compact 10,000mAh power bank is the best balance between useful capacity and luggage weight.
Worth considering if: you use your phone heavily while travelling, spend long days away from plug sockets, use digital boarding passes and maps, travel with children’s devices, or regularly take long flights and transfers.
Probably unnecessary if: you spend most of the holiday near reliable charging points and your phone comfortably lasts all day.
What matters most: usable capacity, USB-C charging, output speed, size and weight, and whether it complies with current airline rules.
Power banks are usually advertised by capacity in milliamp hours, or mAh.
Common sizes include:
A higher number means a larger battery, but it doesn’t translate directly into that exact amount of power reaching your phone.
Energy is lost during voltage conversion, charging and heat generation, so the usable capacity will always be lower than the headline figure.
That’s one reason independent testing is useful: two power banks claiming the same capacity can deliver noticeably different real-world results. Which? specifically tests actual charging performance rather than relying only on the stated specification.
Sometimes.
A small 5,000mAh unit can be ideal if you mainly want an emergency top-up to get your phone through the rest of the day.
The advantage is size. Some are genuinely pocketable and weigh very little.
The limitation is obvious: there isn’t much reserve.
If several people might need power, or you expect to rely heavily on your phone for a full day of sightseeing, a small power bank can run out surprisingly quickly.
We’d view 5,000mAh as an emergency charger rather than an all-purpose holiday power source.
For most people, this is where we’d start.
A good 10,000mAh power bank usually offers enough capacity to make a meaningful difference over a long day while remaining compact enough for a handbag, daypack or aircraft cabin bag.
You’re not carrying a brick around all day, but you have much more headroom than a tiny emergency charger.
Modern 10,000mAh models can also offer fairly high USB-C charging speeds, so you don’t necessarily have to sacrifice performance for portability.
For a typical holiday involving one or two phones, we think this is the most sensible default.
A larger model starts to make more sense if you’re charging:
Several devices: for example two phones, headphones and a child’s tablet.
A tablet or laptop: especially if you need higher USB-C output.
Devices over several days: such as camping, festivals or long travel days without reliable sockets.
Multiple family members’ phones: where one shared power bank replaces several smaller ones.
The downside is weight.
A 20,000mAh power bank is noticeably heavier and bulkier than a 10,000mAh model, so there’s little point carrying one every day if you never use the extra capacity.
Capacity tells you how much energy the power bank stores. Wattage tells you how quickly it can deliver it.
A basic power bank might charge a phone perfectly well overnight but feel painfully slow during a short airport stop.
If your phone supports USB-C fast charging, a power bank with higher USB-C output can make much better use of a 20- or 30-minute charging opportunity.
For most modern phones, we’d look for a USB-C model with sensible fast-charging support rather than an old low-output USB-A-only design.
If you want to charge a laptop, the required wattage becomes much more important.
If you’re buying a new power bank, we’d strongly favour USB-C input and output.
It means:
Some newer models even use a short built-in USB-C cable as a carrying strap, which can eliminate one loose cable from your bag.
That’s the kind of feature we like because it genuinely reduces travel clutter rather than simply adding another gimmick.
They can be genuinely useful.
A power bank with a built-in USB-C cable means you don’t have to remember a separate lead every time you leave the hotel.
That’s particularly attractive for day trips.
The downside is durability. If the built-in cable fails, part of the usefulness of the product disappears.
So we’d still prefer a model that also has normal charging ports rather than relying entirely on a fixed cable.
INIU 10,000mAh 45W power bank
This is the kind of model we’d investigate first for most travellers.
Current versions combine a compact 10,000mAh capacity with considerably faster charging than older budget power banks. One current INIU model also includes a USB-C cable integrated into its carrying loop, which is a genuinely practical travel feature rather than decoration. Recent UK coverage lists the model at 10,000mAh, 45W output and around 160g. The Sun
That combination — compact size, decent output and useful capacity — is very close to what we’d want for a general holiday power bank.
Anker 10,000mAh power bank
Anker would be another brand we’d investigate.
There are several 10,000mAh models in its range, so we’d choose the exact Amazon listing based on output, size and current value rather than treating every Anker model as interchangeable.
The appeal is less about exotic features and more about choosing a well-established charging brand in a product category where battery quality matters.
20,000mAh alternative
We’d also include one larger option for families, tablets and people who genuinely need more reserve power.
We wouldn’t make 20,000mAh the default recommendation simply because it has a bigger number. The extra weight needs to be justified by the way you travel.
Yes, but there are important restrictions.
Under current UK CAA guidance, power banks must be carried in cabin baggage and must not go in checked luggage. The CAA also says passengers may carry no more than two power banks per person, they must be protected against short circuits, and they must not be recharged on board. Current guidance also says they should not be used to charge another portable electronic device during the flight.
The rules changed on 27 March 2026, so older advice online may now be out of date. CAA
Airlines and regulators usually express battery limits in watt-hours, or Wh, rather than mAh.
The CAA says lithium-ion power banks up to 100Wh can be carried without airline approval. Units above 100Wh and up to 160Wh require operator approval, while larger ones are not permitted in ordinary passenger baggage.
If the Wh rating isn’t printed, the CAA gives this calculation:
Wh = voltage × amp-hours
For mAh:
Wh = voltage × mAh ÷ 1000
Most normal phone power banks are comfortably below 100Wh, but we’d still check the label before flying.
This is a good example of why “bigger is better” doesn’t necessarily apply.
A huge battery may offer more capacity, but it can also become heavier, less convenient and more complicated to fly with.
For ordinary holidays, a 10,000mAh or 20,000mAh unit usually gives plenty of useful capacity without approaching the limits associated with very large batteries.
We’d also favour products from reputable suppliers. The CAA specifically advises passengers to choose reputable brands and suppliers when buying lithium-battery devices and to avoid using batteries that are damaged, swollen or overheating.
In your cabin baggage.
Do not put a power bank in checked luggage.
The CAA says lithium batteries can overheat and advises passengers to keep power banks with them in the cabin. If your cabin bag is unexpectedly taken at the gate and placed in the hold, remove the power bank first.
Some airlines may also have their own additional requirements, so check the airline before travelling.
Not necessarily.
For a couple, one good 10,000mAh unit may be sufficient if both phones usually last most of the day.
For a family with several phones, headphones and tablets, either two medium-sized power banks or one larger model may make more sense.
We’d think about how many devices are likely to need charging at the same time, rather than automatically buying one for everyone.
We think it earns its place particularly well on:
Long travel days: airports, flights, trains and transfers can mean hours away from sockets.
Sightseeing days: especially if you’re using maps, taking lots of photos and running the screen at high brightness.
Theme parks and attractions: where tickets, reservations and payment may all depend on your phone.
Family holidays: children’s devices can drain batteries very quickly.
Older phones: battery capacity naturally degrades over time, making a power bank even more valuable.
If your phone comfortably lasts from morning until bedtime and you spend most of the holiday near charging points, you may rarely use one.
The same applies if you’re mostly staying at a resort and not relying heavily on your phone away from the room.
A travel accessory doesn’t become essential just because it’s popular.
If it lives untouched at the bottom of your bag every day, it isn’t earning the weight you’re carrying.
For most travellers, we’d choose 10,000mAh.
It offers enough reserve power to be genuinely useful without turning into a heavy object you resent carrying around.
Choose 5,000mAh if you only want an emergency top-up and size matters more than capacity.
Choose 20,000mAh if you regularly charge several devices, need multiple days of power, or have a genuine use for the extra capacity.
Whichever size you choose, we’d prioritise a reputable brand, USB-C, enough charging speed for your devices and clearly marked battery specifications.
And if you’re flying, remember that the power bank belongs in your cabin baggage, not your checked suitcase.
INIU 10,000mAh 45W Power Bank
View on Amazon →Anker 10,000mAh 30W Power Bank
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