Power banks have come a long way in a short space of time, and while you can just pick up and use any old model you'd be seriously missing out if you did so. With so many differing designs and capacities, and the number, variety and performance of both inputs and outputs, power banks are anything but created equal.
The design and capacity of a power bank are probably the two things you're most likely to consider when choosing a power bank. Is this thing going to fit in your pocket, is it going to weigh down your bag, and how many times will it charge your phone? But there is so much more to consider. Let us explain...
What to look for in a power bank
How big and heavy is this bank - is it going to be a pocket job or weigh down your rucksack? Does it look good and feel well made (is there a warranty?), or is it just another boring black plastic power bank? Is there an LCD that offers an exact readout of how much power remains (preferable to LEDs in high-capacity banks)? Is it waterproof or rugged, suitable for use at festivals or when camping? Is there a built-in LED torch or lanyard? Is there a solar panel for extended use away from mains power?
How many times will this power bank charge your phone? Unless otherwise stated the vast majority of power banks run at 65 percent efficiency, which means a 3000mAh power bank will not fully charge a 3000mAh smartphone battery, though it may get close enough to get you out of a sticky situation when you run out of juice.
The higher the capacity the bigger and heavier the power bank will be, though some more compact designs are achieved by using slimmer battery tech. (You can't take anything higher than 27,000mAh (100Wh) on a plane without the airline's approval.)
Inputs & outputs
Not only the connectors themselves - Micro-USB, USB-C, Lightning and now even full-blown AC adaptors - but the number of those connectors (how many devices do you need to charge at once?).
If your phone supports Quick Charge, look for a power bank that also supports the standard. As a general rule, 5W (5V, 1A) is slow, 10W (5V, 2A) is fast, and anything higher than this is excellent.
Don't be fooled by clever marketing: the claimed intelligent technology that optimises the amount of power delivered to your device is really useful only when you're sharing the bank's maximum output between several connected devices, because your phone will draw only the charge it requires.
Some devices, such as laptops, require more powerful 'USB PD' (power delivery, which can deliver up to 100W) chargers - see our separate guide to laptop power banks.
Remember that speed is important on the output but also the input - most power banks aren't sold with chargers, so if you want to make maximum use of a fast input be sure to pair it with a similarly specced charger.
Remember that eventually your power bank will run dry, and when that happens you'll need to charge it as well as the device you were previously using it to charge. The best power banks support passthrough charging, which means they can be charged at the same time as you any devices connected to their outputs, requiring only one mains power outlet and minimal faffing around with adaptors.
1. Xiaomi Mi Pro Power Bank 10,000mAh
The design is something special, super-thin at 12.58mm and clad in tough-feeling yet premium-looking matte-finish aluminium, in rose gold or space grey. It looks a lot more expensive than it is, and stands apart from a sea of boring black plastic power banks.
Roughly 1.5- to 2 times thicker than most smartphones it's a similar width but shorter, making it a great fit in the pocket. Its rounded edges make the Pro Power Bank feel great in the hand, too.
Xiaomi claims you'll see around 7,100mAh available to your devices, which is good for two- to three full charges of your phone.
Charging is incredibly fast, supporting 18W on both input (USB-C) and output, and the Mi Pro Power Bank also supports passthrough charging. With a compatible charger you could see this power bank go from 0- to 100 percent in just 3.5 hours. A Micro-USB cable with attached USB-C adaptor is supplied in the box.
If you haven't got around to upgrading your tech to USB-C just yet, there's also a Micro-USB version of Xiaomi's 10,000mAh Power Bank. The Mi Power Bank 2 is available from Amazon for £21.49 and looks almost identical, with the same slick aluminium housing. It's a fraction thicker, at 14.1mm, and can also deliver an 18W output, but the input is rated at 15W and the actual output is 6,900mAh.
If you need more power than this the Mi Power Bank 2C is a 20,000mAh version of the Power Bank 2, but with two full-size USB outputs. It's significantly smaller and lighter than the 20,000mAh models lower down this chart, with faster performance (it can be recharged in half the time) and support for passthrough charging. It's a great deal at £34.99 from Amazon, or £26.90/$33.98 from GearBest.
All three of these power banks support a low-charging mode suitable for fitness trackers and other low-power tech. Simply double-press the power button to activate.
2. Zendure A2
The Zendure A2 leaves a lot of our boxes unticked, and yet it's one of our favourite all-rounders in the power bank market. What gives?
Quite simply, there is no other power bank that hits the same sweet spot of price, portability, capacity, performance and design. It's available now from Amazon for an affordable £36.99/$29.99.
It's made from a cool-looking and virtually indestructible crushproof PC/ABS composite material with dual-injection moulding and a shock-absorbing central belt, with four LEDs denoting its remaining capacity. Zendure has shown these power banks get run over by cars and still they survive to charge another phone.
Zendure is in the process of updating many of its models with USB-C and Quick Charge support, but even without those things these older models have a lot to offer. A standout feature is their much higher than industry average 80 percent efficiency rating, and they also have a ridiculously long standby time - six months after you forget about this bank in a drawer it will still have just as much power inside.
The A2 is incredibly compact and pocketable at 137g and 93x48x23mm. Zendure has done a great job of cramming in the power here, too, with a claimed capacity of 6,700mAh. You should see around 5,360mAh of that, thanks to the higher efficiency rate, which should be enough for at least two full charges before needing to recharge the bank.
Although it has just the one USB output it's rated at 10.5W, which offers fast charging for all devices. We're pleased to see passthrough charging, allowing you to charge it and a phone from a single power socket, but even on its own a 7.5W input allows you to recharge the bank in just four hours over Micro-USB.
Learn more in our full Zendure A2 review.
3. Anker PowerCore Speed 10000 QC
The PowerCore Speed QC from Anker is a very close third to the Zendure A2 and Mi Pro Power Bank. With a 10,000mAh capacity (expect around 6,500mAh to be available to your device) it's got enough juice to quickly charge a phone several times, yet it's compact enough to fit in a pocket - the perfect combination. Anker claims it's 27 percent smaller than comparable banks at this capacity, and it weighs just 198g.
It's a fairly simple looking black plastic power bank, but it feels well made and, reassuringly, comes from Anker - a brand well known in the power bank world - with an 18-month warranty. In exchange for this minimal design you get a very reasonable price, £27.99/$34.99 from Amazon at the time of writing.
There's just a single input and single output, with four blue LEDs on top to show how much power remains. So it's nothing fancy, but the PowerCore Speed is functional and intuitive in use.
The Speed 10000 QC is an upgraded version of the PowerCore 10000, and you'll notice it has a blue plastic prong inside its full-size USB output to indicate the improved performance. It supports Quick Charge 3.0, Voltage Boost and PowerIQ, and these three performance technologies combined in essence ensure that any connected device is charged in the shortest amount of time possible.
If you don't have a Quick Charge-enabled phone you'll still get 12W from this output, and the input is also fast to refill the bank at 10W. Unfortunately there's no support for passthrough charging, which would have been the icing on the cake.
Also new with this version is a bundled mesh carry case, which is handy for keeping together the power bank and necessary cables.
Overall a fantastic buy. Learn more in our full Anker PowerCore Speed 10000 QC review.
4. Anker PowerCore II 10,000 Slim
A variation on the PowerCore Speed at the top of this chart with a longer, slimmer, rectangular body and new PowerIQ 2.0 technology that allows it to offer 18W fast charging from a single chipset, the PowerCore II 10000 Slim is actually a couple of pounds cheaper at £25.99/$35.99 at Amazon at the time of writing.
Like that model it has an efficiency rating around 65 percent, so it's good for charging most Android phones twice and iPhones three times.
There's also a 20,000mAh version, which costs £41.99/$56.99, but bizarrely looks completely different to the Slim. It is not only twice the capacity but has twice the number of LEDs that denote how much power remains, and features an extra full-size USB output.
Only one of these two outputs is an 18W PowerIQ 2.0 port, however, with the second a 12W PowerIQ 1.0 output. This is still 'fast' when compared to the 5W chargers bundled with iPhones and some other smartphones.
One thing we really like about this upgraded model is that the improved performance is also available on the input, which means you can recharge the Slim in just 4 hours.
So it's 'technically' better than the PowerCore Speed, but we prefer the design of the Speed, and sometimes that can be the most important criteria of all. The extra height of this bank makes it feel bigger than the squat model, even though it's also slimmer.
Learn more in our full Anker PowerCore II 10000 Slim review.
5. ZMI PowerPack 10K
We really like this ZMI PowerPack, and it should probably sit a little higher up our chart, but it's brand-new and not easily available in the UK just yet.
In the US you can pick one up from Amazon for $20.99, but in the UK you'll need to import one from China via BangGood at £19.11. (It was actually supplied by GearBest, but it's not in stock there at the moment.)
The PowerPack has a unique textured design that makes it very grippy, either on a desk or in the hand, yet below its matrix of thousands of tiny dots is a high-gloss surface, which creates an aesthetically pleasing overall look.
It feels incredibly compact for a 10,000mAh bank, weighing just 117g and only 12.7mm thick. We also like how fast this thing is, supporting Quick Charge on both input and output, helping us to overlook the lack of passthrough charging, and the fact it has both Micro-USB and USB-C inputs.
Let's hope the ZMI PowerPack becomes more easily available in the UK asap.
6. Iceworks 7000
The Iceworks 7000 is a very similar setup to the Flux Charger below, with a lower price (£19.95 at Amazon) and easier availability, but just the one built-in cable.
The version we're testing is a USB-C model, with that being very much the standard for new Android phones today, but it does rule out iPhone users and those running older Android phones with a Micro-USB connection.
The Iceworks is a fast charger for your phone or tablet, with both input and output rated at 15W. The output is of the USB-C variety too, so you can use your standard phone charger to juice it up in around four hours, and it'll recharge while charging your connected phone.
Perhaps more interestingly, the USB-C input is also an output, so you can actually charge two connected devices at once if required.
The design is good, but while it's just 9mm thick it still feels rather large for a 7000mAh power bank (of which you'll see around 4,550mAh). It's taller and wider than our connected Galaxy S8 at 156x78mm, which makes it feel less comfortable when stashed in a pocket.
But assuming you'll be throwing this charger in a bag it won't weigh you down at 159g, and we like not having to carry separate cables. You don't really need it, but the mesh carry case supplied in the box is a nice touch.
7. Anker PowerCore Lite 10000
Yet another 10,000mAh variation on the Anker PowerCore series is this Lite model. This one is a similar shape to the Slim, but with a textured top surface that aids grip in the hand and more rounded edges. Four LEDs are tucked away on the side and easy to miss.
It's exactly the same price, at £25.99/$33.99 from Amazon, and has the same usable capacity of around 6,500mAh. That's enough for two- to three charges of your phone, depending on the model.
Where this model differs is with its two inputs: one Micro-USB and the other USB-C (you can't use both at once, and it still doesn't support passthrough charging), making it easier to charge up the bank with whatever cable you have to hand (a Micro-USB is supplied in the box along with a cloth carry case). Both are rated at 10W, which is pretty fast.
This is not a PowerIQ 2.0 model like the Slim, which means it isn't able to match the output speed from a single chipset. This power bank's full-size USB output maxes out at 12W, which is still very fast, but it's not Quick Charge fast.
8. Teclast T200CF
It's not often you find a power bank with an LCD screen at this price, but if you can get one they are incredibly useful - especially on high-capacity banks - for giving you an exact readout of how much power remains. The last thing you want is to think you've got enough power left to charge your phone and then run out right when you need it.
The Teclast T200CF is a 20,000mAh power bank available in baby pink, baby blue or white, supplied to us by GearBest (where it is now out of stock) but also available from Amazon where it costs £23.62/$30.99. That Amazon description is a bit confusing, mind: no way is this a 'mini' power bank when it weighs 437g and measures 160.8x80x23.7mm.
Of course you would not expect a 20,000mAh power bank to be small, though this is actually a little larger than some examples we've seen from the likes of Anker. You'll find those in our round-up of PD chargers.
As with the Romoss below, around 13,000mAh of that power will be available to your devices, which means you might charge an iPhone seven times. In fact, bar the LCD screen, the spec is very similar. Also here you'll find two USB outputs, one at 10.5W and the other 5W, and both Micro-USB and Lightning inputs rated at 10W.
There's no Quick Charge or passthrough charging support. (Though we could charge both our phone and the bank at the same time this worked only when we plugged in the phone first, suggesting it perhaps wasn't meant to.)
This bank is plastic, but the baby blue and pink colour options are interesting - so many power banks adopt the same boring black design. Sadly our review sample is white!
9. Romoss Ace 20 Power Bank
Another dual-input power bank is the A20 from Romoss. This 20,000mAh power bank has both Micro-USB and Lightning inputs, which makes it easier for iPhone users to recharge the bank without having to also carry around a Micro-USB cable.
The A20 was supplied to us from GearBest, a Chinese importer, where it costs £23.16/$29.26. That's actually a very good price for a power bank of this capacity, but we tend to refrain from reviewing power banks available only in China - they are so easily and cheaply available in the UK that it makes little sense to import them. However, there is also a 10,000mAh version of this power bank, the A10, which you can find on Amazon for £19.90/$19.99.
Available in rose gold or grey, despite its low price the A20 has a fancy aluminium coating that makes it feel pretty cool. But save for the design, Lightning input and capacity (of which around 13,300mAh should be available to your devices), there's nothing particularly exciting about this power bank.
There's no support for passthrough charging, which is on our list of must-haves for high-capacity power banks (especially given this one will take 13 hours to charge over the 10.5W input), and neither is it particularly fast. Though one of the two outputs is rated at 10.5W, the second is just 5W, and if you use both together that 10.5W is shared between the two resulting on slow charging from both.
Still, if needs must, this bank could potentially charge your iPhone seven times. Just be aware that with big capacity comes big weight: the A20 weighs a very noticeable 491g.
10. Flux Card
We've included the Flux Card power bank in this round-up because it's a great example of an all-in-one power bank, though it's not the easiest device to get hold of in the UK.
Right now it's on offer at $29.95 (£23.45) on the company's website (down from $39.95/£31.28), but if you want one in the UK you should also factor in $9.50 (£7.44) shipping and the fact you may also have to pay Customs charges.
When we say 'all-in-one' power bank we mean one that includes all the necessary cables for charging your device, resulting in a much sleeker overall package. Typically such devices make you choose Micro-USB or Lightning, but this power bank supports both. All that's missing is USB-C.
It's slim, portable and, since we wrote our original Flux Card review the company has updated its device, now clad in durable black or white aluminium rather than plastic, and still incredibly thin at 7.8mm. It weighs a tiny 88g.
It has a 4,000mAh capacity, which is going to be good enough for a full charge for any phone, and it's reasonably speedy with a 7.5W input and 10.5W output. Passthrough charging is supported, which is a nice extra.
In common with nearly every power bank you'll find today Flux offers four LEDs to show how much power remains, and boasts smart technology to recognise your device and deliver an optimum charge.
Learn more in our full Flux Charger review.
11. Moshi IonBank 3K
Another all-in-one power bank, but this one's reserved just for iPhone users with built-in Lightning and full-size USB ports, and no other connectors.
The IonBank 3K from Moshi is unashamedly expensive, at least in the UK, costing £54.95/$34.99 at Amazon. We think iPhone users will find it well worth the outlay, however, just for its design alone.
This is a reddot-award-winning power bank with a luxury vegan leather case, which hides away from view all the messy hardware specs that must be printed on a power bank's case. The attached cables are flat and tangle-free (and also non-replaceable), and the aluminium accents with single LED built into a power button make for an exquisite overall look.
The specs are pretty good too. Moshi's 3,200mAh capacity and 65 percent efficiency result in a bank that will offer a full charge to any standard iPhone, and around 70- to 80 percent charge to the Plus models or iPhone X.
Passthrough charging is supported - SmartSense even lets you sync data through the power bank when connected to a computer - and charging/recharging fast. The IonBank 3K has a 12W input and 10.5W output.
Learn more in our full Moshi IonBank 3K review.
12. Moshi IonSlim 5K
Another model from Moshi, but this time suitable for everyone, is the 143g IonSlim 5K. It's just as expensive as the IonBank 3K, costing £54.95/$54.95 at Amazon, but packs in more power with a 5,150mAh battery. (There's also a 10K model if your pockets are especially deep.)
A lot of what you're paying for here is the design, and the aluminium-clad IonSlim is a crazy 8.5mm thick - that makes it just a fraction thicker than the USB output found at one end.
There's also a USB-C port, which is both input and output. It's fast at 15W, which means charging the power bank itself doesn't take significantly more time than charging your phone, but we'd have been more impressed were it to provide support for passthrough charging.
Other features are reasonably basic, and this is one of few recent power banks we've tested not to support auto-on. You'll need to plug in your device and then press the power button, which just seems like an unnecessary extra step in this day and age.
Learn more in our full Moshi IonSlim 5K review.
13. Zendure A6PD
We've concentrated on standard USB power banks in this chart, but that's to ignore an entirely new category of devices that build in USB Power Delivery support. Power Delivery devices can output up to 100W, which means they are technically capable of driving a USB-C-powered laptop or games console.
Power Delivery chargers can be confusing, however, since not all make it clear in their marketing their exact power output, and some are a long way from that magical 100W. This is actually more important than most users will realise, too: a 29W power bank isn't going to charge a laptop that requires 45W.
It's no surprise that Power Delivery banks cost more than standard power banks, and that's why you'll find Zendure's offerings toward the bottom of our chart. Most users will not need to spend this amount on a power bank, but for those who do they make excellent purchases.
The A6PD (reviewed here) is a 20,100mAh power bank with a 45W output, available from Amazon for £69.99/$72.99. If this isn't enough juice then there's also the A8PD, which has a 26,800mAh capacity but slightly lower 40W max output. It's not available on Amazon UK just yet (coming soon), but in the US you'll pay $94.99 (also via Amazon).
Aside from the capacity the two power banks also differ in the number of outputs they offer. While the A6PD offers a single full-size USB output, a USB-C input/output and a Micro-USB input, the A8PD has swaps the Micro-USB port for an additional three full-size USBs. It will charge in just five hours using a 30W USB PD charger.
In other respects the two Zendure power delivery banks offer all the things we expect from Zendure, including the crushproof casing, passthrough charger and higher-than-standard efficiency rating and standby.
See our Power Delivery Power Banks round-up for more details.
14. RavPower PowerStation Series 20100mAh Portable Power Outlet
This RavPower PowerStation sits at the bottom of our chart not because it's not any good (actually we wouldn't recommend anything here we wouldn't personally own and use ourselves), but because for most users it will be overkill, and probably over budget. The PowerStation is available from Amazon for £89.99/$95.99, and there is plenty here to warrant that somewhat extravagant price.
The PowerStation stands out for its inclusion of an actual plug socket - and not a US or EU two-pin plug that you need to pair with an adaptor, but an actual UK three-pin plug, rated at 65W. These things are hard to come by. (That said, if you need a two-pin version there's also the £119.99/$129.99 RavPower PowerStation 27,000mAh version, reviewed here.)
As well as the plug there's a 19V/1.6A DC jack for significantly faster recharging - despite its huge capacity you can recharge this bank in just four hours, when a comparable bank might take 13 hours over a standard Micro-USB input.
At 69x69x146mm this power bank isn't going to fit in anyone's pocket, but it does come with a hard mesh case and all the necessary attachments (including some carabiner clips). And it does have enough power to fill an iPhone seven times, and most Android phones four or five times.
Now you're probably not want to carry your actual phone charger with you to plug into this thing, but RavPower has you covered here too with a 15W USB-C output and 12W 'iSmart' USB output. Both these ports are pretty fast, if not Quick Charge fast.
This is a reddot award-winning design, and we love the soft-touch rubbery finish and rounded corners that make it feel less unwieldy and prone to damage. A plastic LED strip running around the middle breaks the black, and the small vents top and bottom help with heat dissipation.
Learn more in our full RavPower PowerStation 20,100mAh review.