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Best power banks and portable chargers: tested and reviewed
Power banks are big rechargeable batteries with built-in USB ports, and their flexibility and portability make them one of the most useful accessories you can carry for keeping your devices topped up.
We've tested more than 100 power banks over the years from brands including Anker, Samsung, Belkin and INIU, assessing how easy they are to use, their features and charging times.
We've split our reviews between small, medium, and large power banks, with Best Buy recommendations in each category. Some of the best power banks can charge your smartphone in under 70 minutes. The most sluggish can take almost three and a half hours.
How our tests find you the best
Number of charges
Portable chargers don’t always give as much power as they promise which is why we test with real devices. Some couldn’t even power one full charge.
Power bank charging times
Power banks aren’t very portable if you're waiting six hours for them to charge before heading out. We time how long they take to top up at a plug.
Device charging times
How fast can it rescue your phone from the despair of 1%? We time charging speeds with smartphones and tablets, so you’re never left on red for long.
We also test...
Big or small? Basic or packed with extras? We size up every power bank and its features to help you find one that fits your life and your pocket.
The best small power banks from our tests
Smaller power banks tend to weigh around 115g, are approximately the same size as a deck of playing cards, and will charge the average smartphone from flat to full just once before needing to be charged themselves.
Only logged-in Which? members can view the power bank test results below.
Join Which? to get instant access to our test results and Best Buy recommendations below.
| Power bank | Price | Score | Number of device charges | Power bank charging time | Device charging time |
|---|---|---|---|---|---|
Sign up to reveal Get instant access to this and all our scores and recommendations Unlock tableAlready a member? Log in | 78% | 0.9 | 2 hours 29 minutes | ||
| 72% | 1 | 2 hours 43 minutes | |||
| 66% | 1.1 | 3 hours | |||
| 64% | 1 | 2 hours 31 minutes | |||
| 64% | 1.1 | 4 hours 28 minutes | |||
| 58% | 1 | 3 hours 29 minutes | |||
| 79% | 1.3 | 3 hours 23 minutes |
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Dates tested: June 2024, March 2024, June 2023, December 2022, August 2022, September 2021, April 2021. Page last checked: May 2025. We are not able to show every retailer and cheaper prices may be available. 'Number of device charges' and 'Device charging time' are based on charge performance with the selected power bank and a Samsung Galaxy S20 5G smartphone (which has a 4,000mAh capacity battery). Not every small power bank in the table can deliver a full charge to this smartphone, so we have used star ratings rather than times for the 'Device charging time' column.
After something that can deliver more charges to your devices before needing charging itself? Check out the best medium power banks or the best large power banks
The small power banks we tested
All the small power banks we tested are listed in alphabetical order below.
Only logged-in Which? members can view the best power banks from our tests.
Join Which? to get instant access to our test results and Best Buy recommendations below.
Anker 321 Power Bank PowerCore 5K
Most recently tested December 2022
Size and weight 2.2 x 4.5 x 9.7cm (HxWxL); 130g
Capacity 5,200mAh
Need to know USB-C input/output, USB-A output
Anker Nano Power Bank
Most recently tested June 2024
Size and weight 3.7 x 2.5 x 7.7cm (HxWxL); 101g
Capacity 5,000mAh
Need to know Power delivery fast charging, 2 USB-C inputs/outputs
Anker PowerCore 5000
Most recently tested April 2021
Size and weight 10.7 x 3.2 x 3.2cm (HxWxL); 132g
Capacity 5,000mAh
Need to know Micro USB input, USB-A output
Groov-e Power Stick CH5000
Most recently tested August 2022
Size and weight 1.4 x 6.3 x 9.3cm (HxWxL); 109g
Capacity 5,000mAh
Need to know Micro-USB input, USB-C input/output, USB-A output
Hama Slim 5HD Power Pack 5000mAh
Available from Amazon (£12.99) and Ryman (£16.99)
Most recently tested August 2022
Size and weight 1.4 x 6.5 x 9.2cm (HxWxL); 109g
Capacity 5,000mAh
Need to know Micro-USB input, USB-A output
Juice ECO 2 Power Bank 5000mAh
Most recently tested June 2023
Size and weight 1.4 x 6.4 x 9.3cm (HxWxL); 110g
Capacity 5,000mAh
Need to know Micro-USB input, USB-C input/output, 2 USB-A outputs
Mophie Powerstation 5000mAh (fabric)
Most recently tested April 2021
Size and weight 1.1 x 6.9 x 13cm (HxWxL); 127g
Capacity 5,000mAh
Need to know USB-C input/output, USB-A output
In the market for a new smartphone with better battery life? See our pick of the best smartphones at different price points
The best medium power banks from our tests
Medium power banks represent a nice balance between portability and capacity. They're about the same weight as a paperback book, can fit into a large pocket, and have enough capacity to charge a smartphone twice.
Only logged-in Which? members can view the power bank test results below.
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| Power bank | Price | Score | Number of device charges | Power bank charging time | Device charging time |
|---|---|---|---|---|---|
Sign up to reveal Get instant access to this and all our scores and recommendations Unlock tableAlready a member? Log in | 86% | 2.3 | 2 hours 8 minutes | 1 hour 32 minutes | |
| 82% | 2.1 | 2 hours 43 minutes | 1 hour 8 minutes | ||
| 77% | 2.3 | 2 hours 57 minutes | 1 hour 45 minutes | ||
| 75% | 2.2 | 2 hours 41 minutes | 1 hour 24 minutes | ||
| 75% | 2 | 2 hours 56 minutes | 1 hour 48 minutes | ||
| 66% | 2.4 | 5 hours 4 minutes | 3 hours 27 minutes | ||
| 44% | 1.7 | 5 hours 29 minutes | 3 hours 2 minutes |
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Dates tested: June 2024, March 2024, June 2023, December 2022, August 2022, September 2021, April 2021. Page last checked: May 2025. We are not able to show every retailer and cheaper prices may be available. 'Number of device charges' and 'Device charging time' are based on charge performance with the selected power bank and a Samsung Galaxy S20 5G smartphone (which has a 4,000mAh capacity battery).
Fancy a few more charges to make sure your device lasts your entire trip? Check out the best large power banks. Or if you’re after something even more portable, head to the best small power banks
The medium power banks we tested
All the medium power banks we tested are listed in alphabetical order below.
Only logged-in Which? members can view the best power banks from our tests.
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Belkin Boost Charge USB-C PD Power Bank 10K
Most recently tested September 2021
Size and weight 1.7 x 7.5 x 14.3cm (HxWxL); 247g
Capacity 10,000mAh
Need to know Power delivery fast charging, USB-C input/output, USB-A output
Charmast 10400mAh Power Bank
Most recently tested June 2023
Size and weight 1.5 x 6.7 x 14.4cm (HxWxL); 221g
Capacity 10,400mAh
Need to know Micro-USB input, USB-C input/output, 2 USB-A outputs
Duracell Charge 10 Power Bank
Most recently tested March 2024
Size and weight 1.6 x 7.4 x 14.3cm (HxWxL); 247g
Capacity 10,000mAh
Need to know Power delivery fast charging, USB-C input/output, USB-A output
Duracell Core10 PD 25W Power Bank
Available from Duracell (£34.99)
Most recently tested June 2024
Size and weight 7.5 x 1.6 x 16cm (HxWxL); 252g
Capacity 10,000mAh
Need to know Wireless charging, Power delivery fast charging, USB-C input/output, USB-A output
Energizer Max 10000mAh UE10058
Most recently tested August 2022
Size and weight 1.7 x 7 x 14.6cm (HxWxL); 225g
Capacity 10,000mAh
Need to know Micro-USB input, USB-C input, 2 USB-A outputs
INIU BI-B6 10000mAh Portable Charger
Most recently tested March 2024
Size and weight 1.5 x 7 x 13.5cm (HxWxL); 205g
Capacity 10,000mAh
Need to know Power delivery fast charging, USB-C input/output, 2 USB-A outputs
Samsung 25W Wireless Battery Pack
Most recently tested June 2024
Size and weight 7 x 1.5 x 14.8cm (HxWxL); 211g
Capacity 10,000mAh
Need to know Wireless charging, Power delivery fast charging, 2 USB-C inputs/outputs
Our best tablets guide highlights the models that are perfect for on-the-go productivity and entertainment, providing a middle ground between a smartphone's portability and a laptop's functionality
The best large power banks from our tests
The largest power banks we've tested come with four times the capacity of the smallest ones – enough to charge your phone up to five times – though they are often four times the size and weight.
Only logged-in Which? members can view the power bank test results below.
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| Power bank | Price | Score | Number of device charges | Power bank charging time | Device charging time |
|---|---|---|---|---|---|
Sign up to reveal Get instant access to this and all our scores and recommendations Unlock tableAlready a member? Log in | 84% | 4.6 | 3 hours 9 minutes | 1 hour 14 minutes | |
| 80% | 5 | 6 hours 10 minutes | 1 hour 42 minutes | ||
| 75% | 3.4 | 3 hours 46 minutes | 2 hours 3 minutes | ||
| 74% | 4.6 | 6 hours 42 minutes | 1 hour 44 minutes | ||
| 69% | 3.2 | 5 hours 17 minutes | 1 hour 46 minutes | ||
| 67% | 4.3 | 5 hours 28 minutes | 1 hour 25 minutes |
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Get instant access to this and all our scores and recommendations
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Dates tested: June 2024, March 2024, June 2023, December 2022, August 2022, September 2021, April 2021. Page last checked: May 2025. We are not able to show every retailer and cheaper prices may be available. 'Number of device charges' and 'Device charging time' are based on charge performance with the selected power bank and a Samsung Galaxy S20 5G smartphone (which has a 4,000mAh capacity battery).
After something smaller? Check out the best small power banks or the best medium power banks
The large power banks we tested
All the large power banks we tested are listed in alphabetical order below.
Only logged-in Which? members can view the best power banks from our tests.
Join Which? to get instant access to our test results and Best Buy recommendations below.
Anker 335 Power Bank PowerCore 20K
Most recently tested June 2023
Size and weight 2.5 x 8.4 x 16.5cm (HxWxL); 484g
Capacity 20,000mAh
Need to know Power delivery fast charging, USB-C input/output, 2 USB-A outputs
Einova Laptop Power Bank Ultra Fast (63W)
Most recently tested June 2024
Size and weight 10 x 1.6 x 17.5cm (HxWxL); 450g
Capacity 20,000mAh
Need to know Power delivery fast charging, USB-C input/output, 2 USB-A outputs
INIU Power Bank 22.5W Fast Charging 20000mAh
Most recently tested June 2023
Size and weight 2.7 x 7 x 13.5cm (HxWxL); 342g
Capacity 20,000mAh
Need to know Power delivery fast charging, USB-C input/output, 2 USB-A outputs
Juice ECO 5 Charge Power Bank 15000mAh
Available from Argos (£27.99)
Most recently tested December 2022
Size and weight 2.7 x 6.8 x 14cm (HxWxL); 362g
Capacity 15,000mAh
Need to know Micro-USB input, USB-C input/output, 2 USB-A outputs
Juice ECO Max 7 Charge Power Bank 20000mAh
Most recently tested December 2022
Size and weight 2.7 x 6.8 x 14cm (HxWxL); 402g
Capacity 20,000mAh
Need to know Micro-USB input, USB-C input/output, 2 USB-A outputs
Otterbox Wireless, 15000mAh
Most recently tested June 2024
Size and weight 7.3 x 2.5 x 14.6cm (HxWxL); 347g
Capacity 15,000mAh
Need to know Wireless charging, Power delivery fast charging, USB-C input/output, USB-A output
Ebook readers can store thousands of books and magazines, so you'll never run out of reading material. See our roundup of the best ebook readers
Which? Don't Buy power banks
Our tests uncover the best and the worst. If a product performs so poorly that we think you should avoid it, we call it a Don't Buy.
We've tested two power banks that we've named Don't Buys. To find out which they are, and which power banks earned our Best Buy and Great Value recommendations, log in or join Which?.
How we test power banks
To date, we've tested more than 100 portable power bank chargers. The most popular and relevant models are shown on this page. Our rigorous testing programme involves:
- Number of device charges We've often found that devices with the same claimed capacity supply different amounts of energy in real-world conditions; some are much less efficient as they lose lots of energy through heat. We test each power bank on real devices – a Samsung Galaxy S20 5G smartphone, which has a 4000 mAh battery capacity, and a Samsung Galaxy Tab S6 tablet, with a 7040 mAh battery capacity – to see how much charge you'll actually get.
- Power bank charging time We record how long it takes for the power bank to go from 0% battery to fully charged when plugged into a standard wall socket.
- Device charging time We record how long it takes for the power bank to fully charge a Samsung Galaxy S20 5G phone.
- Features This includes the number of outputs and inputs a power bank has.
- Ease of use We assess the portability of the power banks, how well spaced and well labelled the ports are, and how readable their battery power level indicators are.
We regularly revisit the power banks and portable chargers on sale to see if there are any more popular models that need testing and when we find them we do.
Find out more about how Which? is not influenced by product manufacturers or retailers and how your support helps us to stay editorially independent.
What capacity power bank should you choose?
Small power banks can be great for an occasional top up of power on the go – they’re light enough that you’ll hardly feel the weight of them in your bag. Large models give you more juice but are less portable.
- Small power banks (up to 7,500mAh) – usually enough to charge a smartphone once
- Medium power banks (7,500-14,999mAh) – usually enough to charge a smartphone two times
- Large power banks (more than 15,000mAh) – usually enough to charge a smartphone 4 or more times
All of the power banks shown here are intended for charging smartphones and tablets, but only the Einova Laptop Power Bank Ultra Fast has enough wattage to safely top up a laptop while you're out and about. If you try to use a power bank with lower wattage than the laptop's energy demands, the laptop might not get a steady and strong enough flow of power, which causes strain on its battery and leads to damage over time.
Are power banks safe and can you take a power bank on a plane?
As with all batteries, try to keep your power bank at room temperature and keep it away from direct sunlight over a long period of time. Don’t overcharge it either, as this can make it overheat.
We've noticed lots of people asking if you can take a power bank on an aeroplane. For the most part, yes, you can – as long as you keep it in your carry-on baggage and the power bank doesn't exceed 27,000mAh.
As part of your flight, you may be asked for detailed information on the power bank. This is usually printed on the device, but it can rub off with frequent use. If it’s close to the limit and you can’t prove it’s under 100Wh, be prepared to have it confiscated.
Power banks are not allowed in checked baggage because lithium-ion batteries, which are commonly used in power banks, can pose a fire risk if they are damaged or experience a short circuit. While this is incredibly unlikely, ensuring they are stored safely and avoiding excessive physical stress or exposure to extreme temperatures will minimise any potential hazards associated with their use.