Want more help deciding which is best for you? Read our buying advice for the Best Power Banks

1. Zendure A2

Zendure A2
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 23 March 2016

It might seem strange to find a power bank at number one in our chart that doesn't have an LCD screen, doesn't support USB-C or Lightning, doesn't have multiple outputs and doesn't feature Quick Charge 3.0 support. But we stand by our claim that the Zendure A2 is absolutely the best personal power bank on the market. It's compact. It's good-looking. It's fast. It's super-tough. It's plug-and-go. It has enough capacity for several charges and it's great value. A well worthy winner of our best power bank crown.

Read our Zendure A2 review.

2. Anker PowerCore Speed 10000 QC

Anker PowerCore Speed 10000 QC
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 13 July 2017

Fast, portable, high in capacity and affordable. There are some boxes the Anker PowerCore Speed 10000 QC power bank does not tick, yet you’d be pushed to find fault with it at £25. A recommended gadget for the upcoming festival- and holiday season.

Read our Anker PowerCore Speed 10000 QC review.

3. Anker PowerCore II 10,000 Slim

Anker PowerCore II 10,000 Slim
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 16 October 2017

The Anker PowerCore II Slim comes at a good price and has a useful amount of capacity for keeping your phone or tablet topped up away from home. The Quick Charge 3.0 support and fast recharging is very welcome but only for phones that support it, and the design is reasonably attractive as far as black plastic power banks go.

Read our Anker PowerCore II 10,000 Slim review.

4. Zendure A3

Zendure A3
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 30 November 2016

Higher in capacity than the class-leading Zendure A2, but with the same indestructable design and an extra USB output, the Zendure A3 is a great choice if you want a little more pocketable power for charging your phone and/or tablet away from home. If you need more power still check out the £40 Zendure A4, which is otherwise identical to this Zendure A3.

Read our Zendure A3 review.

5. Flux Card

Flux Card
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 18 August 2016

A fantastic upgrade over the original Flux Charger, the new 4,000mAh Flux takes onboard all our criticisms and comes back fighting. An excellent, truly portable power bank that will get any smartphone user out of a jam. If you need more capacity, also see the 10,000mAh Flux Charger Plus, now with two additional full-size USB outputs.

Read our Flux Card review.

6. Romoss RT Pro 10,000mAh Power Bank

Romoss RT Pro 10,000mAh Power Bank
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 24 January 2018

The Romoss RT Pro power bank excels on price and performance, though in design it struggles to stand out. A great choice if you have a Quick Charge 3.0-compatible phone.

Read our Romoss RT Pro 10,000mAh Power Bank review.

7. Moshi IonSlim 5K

Moshi IonSlim 5K
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 4 July 2017

Moshi has created one of the most attractive and portable power banks we’ve seen in the IonSlim 5K - this is one of the few that you really won’t mind carrying around with you. Our only real gripe is the price: £50 is a lot for a 5,150mAh battery, so you’ve got to decide how much of a premium you’re willing to pay for the pared down design.

Read our Moshi IonSlim 5K review.

8. Moshi IonSlim 10K

Moshi IonSlim 10K
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 9 February 2018

The IonSlim 10K is beautifully designed and wonderfully portable, but you'd better be ready to pay for that premium aesthetic. Still, it boasts USB-C PD support, so if you want to be able to top up your laptop and phone wherever you are without carrying around a bulky black brick, this could be the power bank for you.

Read our Moshi IonSlim 10K review.

How to choose the best power bank for you

Power banks typically come in three sizes: small lipstick-style devices that might charge your phone once and cost about a tenner; compact units with a mAh rating of between 5,000- and 10,000mAh that will offer two- or three full charges and might cost around £20; and high-capacity devices that will keep you going for days on end away from mains power and that will set you back anywhere between £25 and £100.

More recently, though, we've seen a new breed of power bank capable of also charging your laptop, with big batteries and either USB-C PD outputs or AC outlets. You won't find those power banks in this round-up, but we've got a separate guide for laptop power banks.

If you're wanting to take a power bank on a plane, know that the maximum capacity you can take in hand luggage is 100W, or around 27,000mAh. 

Whatever its stated capacity, remember that not all of that juice is available for charging. The typical energy efficiency is between 60- and 70 percent, but some go as high as 90 percent - where this is the case it will be mentioned in the product specs. If it's not stated, assume around 60 percent efficiency rating and consider anything on top of that a bonus.

We test lots of power banks, and in this group test have given examples of some of our favourites, but there are so many available on the market and from so many different vendors that you're better off going into this knowing what features you want to look for and then choosing accordingly.

Do you need multiple outputs? Do you want a USB-C or Lightning input/output, or an AC outlet? (The latter are significantly more expensive.)

Would you benefit from passthrough charging (or charge-through) technology, which allows you to simultaneously charge the power bank and a connected device, thereby freeing up power outlets in your home?

Do you want an LCD screen that can give you an exact read-out of what capacity remains or are you happy with LEDs?

Do you need a rugged or waterproof casing? And if you're going away from civilisation would you benefit from a built-in LED flashlight and a built-in solar panel? You might think living in the UK our grey climate would rule out the use of such a device, but even in cloudy conditions these devices can draw some solar power.

Power banks and charging speed

One of the most confusing things for many people when it comes to working out which power bank they should buy is figuring out how fast it is, or rather how fast it should be.

If it's a small device that will fit in your pocket along with your phone then you might not be so worried about how fast it can recharge your handset, but speed is particularly important when you want to charge a laptop or tablet, which may refuse to charge from slower outputs. 

Confusingly, the term 'fast-charging' is thrown around a lot within marketing, and it doesn't really mean anything. The minimum you'll see is 5W, and we would not recommend this. Although some phones are still sold with 5W chargers, most devices will accept more than this.

In our view anything below 10W should be considered standard (read slow), and anything above 10W fast. Then you also have various Quick Charge standards - all of which are backward-compatible - which will get you up to 18W, but only on compatible devices.

If it's a high-capacity power bank then you should look for 'fast-charging' inputs as well as outputs. Do bear in mind, though, that in order to refill a power bank at 18W you will need a mains adaptor that is capable of delivering 18W to it.

Increasingly power banks feature clever technology called PowerIQ or similar. This allows the bank to recognise the type of device you have connected and deliver the optimum amount of power. 

The input rating is key when it comes to recharging the bank - the higher is this figure the more quickly it will charge. You'll see a figure in Amps, and you multiply this number by the voltage (5V for USB) to find the rating in Watts.

You can use any output to charge any USB device - it will draw only the power it needs.

If a power bank has several outputs the maximum total output capacity is key, since it may not be able to simultaneously support each at full power.

What is Power Delivery?

A fairly new standard is Power Delivery, often abbreviated to PD. Most laptops, some tablets, and power-hungry devices such as the Nintendo Switch will not charge over a standard USB connection - it must support PD.

All you really need to know about Power Delivery is that it has the potential to deliver a lot more power - up to 100W. You'll find mains adaptors offering 29W, 45W, 65W and so forth, all of which are PD chargers. The same is true of power banks.

See our pick of the Best Power Bank Deals and Best power banks for Nintendo Switch. Plus: How to charge your smartphone or tablet faster