Your buying guide for the best power banks in 2017

Phones get faster every year, but the more powerful they become the less their batteries can keep everything going. And, of course, all batteries will degrade over time. If you need extra battery power for your smartphonetablet or other USB-powered device, you need a power bank.Also see: How to charge your smartphone or tablet fasterSee our pick of the Best Power Bank Deals and Best power banks for Nintendo Switch

You might assume all power banks are much the same thing, but you would be wrong. You can get compact power banks that will charge your phone once, slightly larger portable chargers that might offer two or three charges, or high-capacity banks that can charge your phone in excess of 10 times! 

Working out how many times a power bank will charge your phone depends on more than the mAh rating on the packaging. No power bank is 100 percent energy-efficient, with every portable charger losing power through voltage conversion and heat generated.

The industry standard for energy efficiency is between 60- and 70 percent, and if it doesn't expressly state otherwise on the packaging this is likely what you'll get. But some of the best power banks can offer as high as 90 percent energy efficiency, which equates to more full charges for your phone.

Power banks can also vary greatly on their inputs and outputs. We're seeing an increasing number of power banks with support for the latest Quick Charge 4.0 and USB-C standards, and in some cases these are supported on the input as well as the output, making them as fast to refill as they are to charge your phone.

Some power banks may offer these in place of or alongside full-size USB, Micro-USB and Lightning ports - which you choose entirely depends on which connection your phone uses, and for how long you intend to keep that phone until you upgrade. (Most power banks are guaranteed for 500 recharges.)

Typically you will need to carry a Micro-USB cable to charge your power bank, and potentially another cable for charging your phone if it doesn't use the Micro-USB connection to charge. Some power banks come with carry cables to ease this requirement; others might feature built-in cables and Micro-USB- to Lightning adaptors so all you need throw in your bag is the power bank itself.

We're starting to see power banks creep on to the market that feature an AC/DC outlet - a plug socket that allows you to plug in much more than USB devices. Unfortunately so far we've seen only power banks with the US two-pin plug, and needing to carry around a UK three-pin adaptor makes them less easily portable and feel less convenient.

Another type of power bank builds in solar panels. 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.

However, the sunnier the conditions the better they work, so if this is the kind of device you're after we'd recommend a model with a built in battery that means you will have power for your phone even when it's dark outside.

Design is important when it comes to choosing a power bank, and some batteries are more compact than others at the same capacity. You can also buy those protected from the elements, but be sure to check whether they are probably waterproof or simply rainproof before leaving them out in the cold.

The ideal power bank is one that's small enough to slip into a pocket or bag without it weighing you down, but with enough juice to keep your phone going all day long.

Something exactly like the Zendure A2 that sits at the top of our chart: it's fast, it's compact, it's got enough power to charge your phone two- to three times, and it has a sufficiently durable casing that you could even run it over in your car.

Nearly all power banks use a series of (typically four) LEDs to show you how much power remains in the device. This is fine for smaller-capacity devices, but when each LED represents two- to three full charges for your phone it can be difficult to see exactly where you are.

We favour power banks with built-in LCD screens, though you will usually pay a little more for the privilege. No power bank we've tested has a more informative and useful LCD screen than the Omnicharge.

For the ultimate in capacity, check out the Maxoak K2.

Advanced features to look out for in a power bank

Next we come on to the more advanced features that are useful to have but not always found in cheaper power banks. Passthrough charging is something we always look for, and is the ability to charge a connected smartphone at the same time as the device itself.

Some power banks say they support passthrough charging, but will actually prioritise the connected device until its battery is full, all the while trickle-charging the power bank itself with whatever power is going spare, then turn their attention to the bank itself. Others will charge both devices at full-speed at once.

We also have our eye on MAGFAST, a new system of wireless chargers that are available for pre-order now. They clip together to form a charging hub, or you can use them separately.

You can use LifeCharger on its own as a powerbank, with a crazy-good four inputs and five outputs. We'll have a full review when they are available.

Auto-on and auto-off is another sought after feature, though it's worth pointing out that sometimes a power bank can support this but your phone won't. It means you can plug in a phone or tablet to charge and the power bank will instantly begin doing its thing without you pressing any buttons. And when charging is complete it will put itself into standby mode in order to conserve energy.

Some power banks, though it's an increasingly rare feature, also come with an LED torch that will usually be activated by double-pressing a button somewhere on the casing.

We're not massive fans of the built-in torch, though we do understand it can come in useful in certain situations, such as camping. In most cases, though, the rather weak LED is of little use in all but the darkest conditions.

Power bank torch

Get the fastest charging and recharging rates

The input rating is key when it comes to recharging the power bank - the higher is this figure the more quickly it will charge.

You'll usually see a figure in Amps, for instance 1A. You multiply this number by the voltage (5V for USB) to find the rating in Watts.

A 1A input can charge at 5W, therefore, but you'd do better to look for a device that can charge at 2A (10W).

Don’t expect to get a USB charger in the box - you can use that which was supplied with your phone or tablet. Do note, however, that a power bank with a 2A (10W) input will not recharge its own battery any faster than one with a 1A (5W) input when used with an underspecified USB charger.

The reverse is also true when it comes to charging your devices - a phone that supports only a 1A (5W) input won’t charge faster from a 2A (10W) output. See also: Expert tips on how to charge your phone

The output rating refers to how quickly a power bank will charge your devices. In most cases you’ll find 1A (5W), 2A (10W) and often even 2.5A (12.5W) outputs, the former intended for smartphones and the latter two for tablets or for fast-charging phones that support the feature. (This is not the same as the Qualcomm Quick Charge feature supported by several flagship phones.)

You can use either output to charge any USB device - it will draw only the power it needs. However, you might find some tablets - usually iPads - will refuse to charge from lower-specified outputs. Also see: What is Qualcomm Quick Charge 4?

Increasingly power banks feature clever technology which is often referred to as PowerIQ or similar. This allows the power bank to recognise the type of device you have connected for charging and deliver the optimum amount of power for that device. 

If a power bank has several outputs then the maximum total output capacity is key. For example, the LimeFuel Blast Pro L240X has four 2.4A (12W) outputs, but delivers only 4.2A (21W) total output. With four USB devices attached you will find that each charges much more slowly.

Can a power bank charge your phone in 5 minutes?

No. Recently, some power banks have started hitting the headlines for their apparent ability to charge your phone in five minutes. It sounds preposterous because it is.

What these power banks are actually able to do is refill their own batteries sufficiently within five minutes that they can then fully charge your phone (which is still awesome, but not quite as awesome as how you first read that news).

How quickly they can supply that power to your phone depends firstly on how much power they are able to output, and secondly how much power your phone can accept.

As an example, the Simpiz iTron, uses DUBI 1.0 technology to refill its own 9000mAh battery in 18 minutes. If you consider that as 3000mAh per six minutes, it would certainly have enough power to fully charge most phones within five minutes.

When it comes to then transferring that power to your phone, the Simpiz iTron's fastest output is Quick Charge 2.0. This is incredibly fast, but if you have or will have one of the latest devices that support Quick Charge 4.0, it's not actually the fastest charge they are able to accept.

There are several examples of Quick Charge power banks in our round-up below. Also see: Graphene batteries: what you need to know.

Read next: Best new phones coming in 2017

Follow Marie Black on Twitter.

Best power banks 2017 UK - best power bank reviews

1. Zendure A2

Zendure A2
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 23 March 2016
  • RRP: £28.31

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 10000

Anker PowerCore 10000
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 20 June 2016
  • RRP: £20, US$29.99

Fast, portable, high in capacity and affordable. There are many boxes the Anker PowerCore 10000 power bank does not tick, yet you’d be pushed to find fault with it at £20. A recommended gadget for the upcoming festival- and holiday season.

Read our Anker PowerCore 10000 review.

3. RavPower PowerStation Series 20100mAh Portable Power Outlet

RavPower PowerStation Series 20100mAh Portable Power Outlet
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 17 January 2017
  • RRP: £99.99, US$119.99

It has a similar usable capacity to the similarly priced Omnicharge, yet lacks its LCD screen and is much larger and less easily portable. However, this RavPower PowerStation Series 20,100mAh Portable Power Outlet is much easier to get hold of in the UK and even comes with a UK three-pin AC outlet. Both devices are expensive at around £100, but offer insanely fast charging (and recharging) of almost anything you like. A fantastic buy if you can afford it.

Read our RavPower PowerStation Series 20100mAh Portable Power Outlet review.

4. CHJDG UltraCompact Power Bank

CHJDG UltraCompact Power Bank
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 6 July 2016
  • RRP: £19.99

CHJGD is doing what it can to bring some colour to the functional-looking power bank market with the bulldog-inspired UltraCompact Power Bank. It has useful capacity, and it is affordable and easily portable. A great buy if you're in the market for a portable charger you can slip into a pocket.

Read our CHJDG UltraCompact Power Bank review.

5. Zendure A3

Zendure A3
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 30 November 2016
  • RRP: £33.95, 37.89

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.

6. DXPower Armor DX0001

DXPower Armor DX0001
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 25 January 2017
  • RRP: £23.99

A good-looking, mid-capacity rugged power bank that will fit neatly into the pockets of campers, hikers and other outdoorsie-types. It's a shame that the DXPower Armor is waterproof only when it's not in use, but this is a criticism we could level at most - if not all - 'waterproof' power banks.

Read our DXPower Armor DX0001 review.

7. Flux Card

Flux Card
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 18 August 2016
  • RRP: £19.13 + $8.50 shipping to the UK, 25

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.

8. CHJGD Magnum Opus

CHJGD Magnum Opus
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 20 December 2016
  • RRP: £29.99

If you need a lot of power, the Magnum Opus is an excellent power bank: fast, high in capacity, affordable and with an LCD screen. Even despite its bulk and lack of passthrough charging, the CHJGD is easy to recommend.

Read our CHJGD Magnum Opus review.

9. Anker PowerCore 20000

Anker PowerCore 20000
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 22 June 2016
  • RRP: £27.99, 49.99

The Anker PowerCore 20000 offers more power than you’re likely to need and, while it’s smaller and lighter than many at this capacity, fast charging means you won’t need to carry it around longer than necessary. A great buy if you’re going to be away from mains power for several days.

Read our Anker PowerCore 20000 review.

10. Zendure A8 QC

Zendure A8 QC
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 22 August 2016
  • RRP: £65.41

Incredibly well designed with excellent features including passthrough charging and an LCD panel, a tough build and huge amounts of power, that £69.41 asking price doesn't look so high after all. The only thing we can fault Zendure on is the fact its three Zen+ ports can't simultaneously run at full speed. However, the new Quick Charge 3.0 input and output, plus increased capacity are very welcome additions, making this an excellent buy if your power needs are great.

Read our Zendure A8 QC review.

11. Lumsing Glory P2

Lumsing Glory P2
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 1 February 2017
  • RRP: £24.99, 27.99

The design doesn’t thrill us, and we’d like to see support for passthrough charging, but the Lumsing Glory P2 offers great value and some welcome features. Few power banks of this capacity will charge in just five hours.

Read our Lumsing Glory P2 review.

12. RAVPower Ace 22,000mAh External Battery Pack

RAVPower Ace 22,000mAh External Battery Pack
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 6 July 2016
  • RRP: £26.99, 39.99

Affordable, high in capacity and able to keep three kids entertained at once, the RavPower Ace 22,000mAh is possibly one of the best family power banks. A great buy if you’re planning a long journey away from mains power.

Read our RAVPower Ace 22,000mAh External Battery Pack review.

13. Iceworks Portable Charger

Iceworks Portable Charger
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 24 August 2016
  • RRP: £20

For Micro-USB-connected Android phones and recent-generation iPhones, the Iceworks 5000mAh Portable Charger is a god-send. It’s slim, stylish and easily portable with no need to carry extra cables. At £20 it’s great value, too.

Read our Iceworks Portable Charger review.

14. Anker PowerCore+ 20100 USB-C

Anker PowerCore+ 20100 USB-C
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 1 December 2015
  • RRP: £80

The Anker PowerCore+ 20100 USB-C is a very decent high-capacity power bank for fast-charging all manner of USB-connected devices, including USB-C models such as the Nexus 5X and Nexus 6P - even if you don't have a USB-C smartphone now, chances are you will do at your next upgrade. It's big and heavy, yet remains stylish and easy to use, and currently offers good value. We'd like to see such things as passthrough charging and an LCD screen, but the LED power wheel is the best implementation we've seen, and we appreciate the Anker's ability to recharge itself in just over eight hours.

Read our Anker PowerCore+ 20100 USB-C review.

15. CHJGD Midas

  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 11 July 2016
  • RRP: £19.99

The CHJGD Midas is a premium-looking power bank that comes at a good price, yet doesn’t skimp on performance.

Read our CHJGD Midas review.

16. Griffin Survivor Power Bank

Griffin Survivor Power Bank
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 26 September 2016
  • RRP: £49.99

It might be on the expensive side for a power bank of this capacity, but the tough little Griffin Survivor has a rugged charm. It’s reasonably fast and it’s rainproof, and there are some nice extras such as passthrough charging, auto-on/-off and a lifetime guarantee. If it’s not all about value for money, this may be the power bank for you.

Read our Griffin Survivor Power Bank review.

17. Dodocool 5000mAh Power Bank

Dodocool 5000mAh Power Bank
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 30 November 2016
  • RRP: £17.99, 21.99

A great-looking compact power bank that has a built-in charging cable for Android or iPhone. Android users will find it slow, but the Dodocool 5000mAh power bank will prove an ideal travelling companion for iPhone users.

Read our Dodocool 5000mAh Power Bank review.

18. RavPower Exclusives 20100mAh Power Bank

RavPower Exclusives 20100mAh Power Bank
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 16 February 2017
  • RRP: £45.99, US$54.99

An attractively designed, high-capacity power bank that’s a touch on the pricey side but won’t disappoint. We’d like to see support for USB-C and Quick Charge, but the RavPower Exclusives Power Bank is a good buy nevertheless.

Read our RavPower Exclusives 20100mAh Power Bank review.