Best power banks
Get the best value, fastest charging speeds and ultimate functionality with our expert advice.
For years now friends, family and even colleagues have wondered how I am able to spend so long playing around with power banks. They just charge your phone, right, so what’s the big deal?
Not all power banks are created equal. You’ve got cheap ones and pricey ones as in all veins of consumer tech, and as with anything else sometimes you’re just paying for a name. But beyond that, there’s so much
more to portable power than a charging brick with a USB output.
What capacity do I need?
Power bank capacity is commonly misunderstood. You don’t need to understand what is mAh, only that if your phone spec says it has a 4,000mAh battery you are going to need at least a 4,000mAh bank in order to get a full charge.
Actually you need more than that. No portable charger runs at 100 per cent efficiency, with most averaging around 65 per cent, and some hitting as high as 80- or 90 per cent. The latter are the ones you want.
In order to fully charge a 4,000mAh battery phone, you’re likely going to need something more like a 6,000mAh power bank. So all those 5,000mAh banks that claim to charge your phone twice, don’t believe a word – not unless you’ve got a really old phone with a tiny battery.
Devices tend to sold in 5,000mAh, 10,000mAh and 20,000mAh capacities, with a few variations in between. As a rule of thumb, 5,000mAh is a single-use power bank that will be easily portable; 10,000mAh hits the sweet spot, both portable and offering at least two full charges; 20,000mAh is high-capacity, most useful for those who are going to be away from mains power for extended periods or will be charging multiple gadgets. Don’t attempt to stuff a 20,000mAh device in your pocket.
Of course you can buy banks with significantly higher capacities, which are particularly useful if you want to charge a laptop, but they are going to be
much bigger, bulkier and more expensive. Do note that if you’re travelling on a plane your portable charger must be in your hand luggage, and anything over 27,000mAh (100Wh) needs approval from the airline (over 43,000mAh/160Wh, forget it).
With great power comes two great problems, however. First, recharging can take forever (okay, like nearly a day in some cases). Secondly, with most devices offering a row of four LEDs to denote how much power remains inside the bank, working out how much you’ve actually got left can be impossible.
Solutions here are simple. An LCD screen will give you an exact read-out of remaining capacity, though these are rarely found on low-capacity and cheap banks. Passthrough charging lets you charge both the
power bank and connected devices at once, freeing up power sockets if you are going to have to leave it plugged in for long periods. Ensuring you have the fastest possible input (typically a USB-C PD input, which can be as high as 100 watts) will also speed things up.
What speed do I need?
If I had it my way 5-watt power banks would be banned. They are painfully slow. Anything lower than 10 watts: no. These days even 10 watts, though marketed as ‘fast charging’, barely scratches the surface of what recent smartphones are capable of. With some able to go as high as 45 watts over a wired connection, a 10-watt power bank is not going to feel especially convenient.
That said, 10 watts is more common among the budget- and mid-range, and many people will be using 10-watt chargers at home. But we’d still recommend looking for a faster power bank, especially those with Quick Charge or Power Delivery support (even if your current phone doesn’t support it, a later upgrade most likely will).
That seems pretty straightforward, although power manufacturers rarely provide the speed of their outputs measured in Watts. Instead you’ll see a rating in Amps, which you multiply by five (the Voltage rating) to get the rating in Watts. So 2 amps x 5 volts = 10 watts.
Which outputs do I need?
Android phones are increasingly moving over from Micro-USB to USB-C, and in which case a USB-C port that acts as input and output is preferable. However, it’s still common for power banks to be recharged over
Micro-USB, and sometimes you’ll find both Micro-USB and USB-C. Don’t try to use them simultaneously for recharging the bank. As a rule of thumb, USB-C is going to be the faster option.
How many ports you need depends on how many gadgets you want to charge at once. If more than one, watch out for power banks with a max output that is lower than the sum of all ports together – they won’t be able to deliver the maximum rated output of all at once. Also watch out for capacities that are too low to fully charge multiple devices.
There is no need to worry about plugging devices into ports that are capable of delivering more power than they are able to accept, since USB devices will draw only the power they need. Many power banks include technology that is able to intelligently dole out this power among ports more appropriately depending on what devices you are attempting to charge (often known as Power IQ or similar).
Wireless power banks are becoming more commonplace, and here you won’t need any outputs if you’re intending to use it only for wireless charging. An input will still be required to recharge the bank itself.
1. Zendure power banks Price: £34.99 from fave.co/2OcYSbU
Zendure is a long-time Android Advisor favourite, with a range of devices starting with the 6,700mAh A2 and culminating in the 26,800mAh A8. Key differences in the range are focused on price, capacity and number of ports, and Zendure is in the process of updating the line with USB-C and Power Delivery.
The A2 stands out to us as the best all-rounder, with an affordable price, a usable capacity and a
compact design. The tech inside is also very good, with super-efficient batteries that can retain 95 per cent of their charge after six months and deliver a higher-thanaverage 80 per cent of their capacity to your phone. There’s passthrough charging, too, so you can charge both the power bank and a connected device from a single power outlet.
The design is notable for its durability, with a cool-looking and virtually indestructible crushproof PC/ABS composite material with dual-injection moulding and a shock-absorbing central belt. Four LEDs denote its remaining capacity, though higher up the line in the A8 you’ll find an LCD screen.
The basic A2 doesn’t support Quick Charge or USB-C, though its 12-watt output is speedy. There’s also a 10.5-watt Micro-USB input for recharging. Look to other Zendure models for these features, plus additional ports.
If the A2 is unavailable the 10,000mAh Ultra-Slim and A3 are very close second-bests.
2. Xiaomi power banks Price: £54.95 from fave.co/2Do4kq8
We’re a little torn between Zendure in first place and the Xiaomi range of power banks, which are not as easy to get hold of but they cannot be beaten on value and are equally well designed.
At the official Mi Store (fave.co/3iNKtkq) you’ll find the 5,000mAh Mi Power Bank 2 (£9.99), 10,000mAh Mi Power Bank 2S (£17.99), and top-end 10,000mAh Mi Power Bank Pro (£24.99).
The Pro is most interesting to us for its 18-watt USB-C port that acts as both input and output. There’s also a full-size USB output, plus support for passthrough charging. (The 2 and 2S are Micro-USB banks.)
At this price you’d typically be looking at a basiclooking matte-black plastic bank with no bells and whistles. These are super-slim aluminium-alloy banks with a premium finish, and despite their reasonable capacities they are compact and feature rounded corners that make them comfortable in a pocket and in the hand.
Also interesting is their support for low-power charging, for devices such as fitness trackers – often
when you attempt to charge a low-power device the bank will automatically turn itself off.
3. Anker power banks Price: £27.99 from fave.co/324FRkb
Anker is a very well-known brand in the power bank market, so you can buy with complete confidence. Its devices are a little more boring in terms of design, standard matte-black bricks, but the performance is all there and they offer great value.
Our favourite of all is the PowerCore Speed 10,000mAh QC, which has a super-compact design that will easily slip into a pocket. Anker claims it’s 27 per cent smaller than comparable banks at this capacity, and it weighs just 198g.
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 10,000 QC is an upgraded version of the PowerCore 10,000, 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 12 watts from this output, and the input is also fast to refill the bank at 10 watts. Unfortunately there’s no support for passthrough charging, which
would have been the icing on the cake. New with this version is a bundled mesh carry case, which is handy for keeping together the power bank and necessary cables.
Also recommended in the Anker line-up are the PowerCore II Slim, another 10,000mAh bank with a more rectangular body and faster 18-watt charging, and the 10,000mAh PowerCore Lite, which has an additional USB-C input.
4. Xcentz xWingMan Dual 10,000mAh Power Bank with PD Price: £29.99 from fave.co/2ObVP3R
We can’t get over the size of this 10,000mAh power bank from xcentz, which makes it the ultimate portable charger for combining capacity and portability. The
xWingMan Dual is the same capacity as the RavPower below, yet significantly smaller at 76x59x27mm.
We really like the design – a small, rectangular block with a soft-touch rubberised casing and rounded corners that make it a comfortable fit in the hand or in the pocket. On the top surface is a high-gloss strip with the xcentz logo and four blue LEDs, and a similarly glossy power button just below is used to activate these LEDs and see at a glance how much power remains.
It’s not just compact and good-looking, the xWingMan Dual is also very attractively priced, and it’s fast. There is a USB-C PD port that can act as both input (12 watts, allowing you to recharge the bank in
3.5 hours) and output (18 watts), plus a full-size Quick Charge 3.0 USB-A output.
We also really appreciate the fact you get not only a USB-A to USB-C cable in the box, but also a USB-C to USB-C cable. Both are relatively short 30cm cables, but that’s not a bad thing.
Do note that the fact two cables are supplied in the box does not mean this power bank supports passthrough charging, which is the ability to charge the power bank and an attached device at once.
The two cables merely let you charge two devices at once, which is also handy for such a tiny device. We’d expect two full charges of an Android phone from that 10,000mAh capacity.
The Xcentz power bank feels incredibly well made, but a two-year warranty adds peace of mind.
5. RavPower PD Pioneer 10000mAh 29-watt 2-Port Power Bank Price: £23.99 from fave.co/3gJ4Ux8
RavPower is another very well-known maker of power banks, and you won’t go far wrong with its products. We particularly like this PD Pioneer model, a compact 10,000mAh power bank that offers fast charging for up to two connected devices.
Don’t be fooled by the 29 watts on the box: that’s the maximum output of the two ports combined, so you shouldn’t get any ideas about being able to charge a USB-C laptop such as a MacBook. To be fair, you wouldn’t really want to use a 10,000mAh power bank to charge a laptop, given that it will quickly run out
of power, but it is an ideal capacity for smartphones – small enough to carry in your pocket or bag, yet sufficient for at least two- and potentially four full smartphone charges, depending on your device.
This RavPower unit has two USB outputs: one full-size QC3/2 port, and the other a USB-C power delivery port that can deliver 18 watts in and out. When recharged using the latter, the RavPower’s capacity is restored in as little as three hours. We also found it was happy to support passthrough charging in our tests (the ability to simultaneously charge the device and charge a connected device).
It’s worth pointing out that although there is a full-size USB port here, only a USB-C to USB-C cable is provided in the box, so if your device does not support USB-C you’ll need to supply your own cable for charging. This cable feels good quality, and we’re confident it should last well. A soft grey carry case is supplied, making it easier to store the necessary cables with the bank.
Though it’s a relatively standard matte black plastic design, the slightly chunky rectangular body of the RavPower makes it a very
comfortable fit for the hand. A thin wedge is cut out from one end of the device, which is where you’ll find the USB outputs, sloping down on one side to reveal four LEDs and a button that allows you to see roughly how much power remains in the bank.