1. Expert reviews

Top 4 Best Powerbanks of 2021

Daniel Hessel

Updated January 21, 2021

Does the battery often run out on your phone? If so, a powerbank could be the perfect accessory for you. But which powerbank is best? We put the most popular models through a tough test.

How we did the test

In this test, we performed calculations and tests on a range of powerbanks. To be able to judge them fairly, we used a battery of 1800 mAh, which corresponds to an average mobile battery, albeit in the slightly smaller class. It's about what you'd find in an iPhone SE from 2020, although many Android phones can be up to 3,000 or 4,000 mAh.

In the test, we used a standard 2 amp Lightning cable.

We tested each powerbank individually and then, through the data obtained, we assessed and compared the different models. Below you can read about the various measurements and what tests we did, as well as a brief explanation of what the results mean.

  • Volts – How much current is flowing through the device.
  • A (Amperes) – How many amperes the powerbank can transfer.
  • Operating time – How long the powerbank can be used before it runs out of battery and needs to be charged.
  • Charges – How many charges can be made to an 1800mAh battery.
  • Charging – How long it takes to charge the powerbank up to 100%.
  • Power – Shows how much current is flowing through the device with the charging cable used during the test.
  • Ports – How many ports the device has and what type, which is important for you to be able to use it with all your devices.
  • Weight – The weight of the powerbank, which is crucial in terms of its portability.
  • Dimensions – The powerbank's dimensions, which also have a major impact on its portability.

1. Mophie Powerstation XL Wireless - BEST PREMIUMCHOICE

Fast and got plenty of functions

Volts: 4.89 A: 1.53 Operating time: 3.92 Charges: 2.90 Charging: 6 hrs 10 min Power: 7.56 Watts Ports: 2 x USB ports, 1 x USB-C, Wireless Weight: 241 g Dimensions: 128 x 69 x 20 mm

Mophie Powerstation XL

The Mophie Powerstation XL is top of the range when it comes to powerbanks and comes equipped with most things you could want. You not only have two USB ports and a USB-C port, but you also get wireless charging, which comes in very handy when you’ve forgotten the charging cable.

With an operating time of 3 hours and 55 minutes, and able to charge your mobile in 2 hours and 50 minutes, you’ll get what you need from this powerbank.

In terms of weight, at 241 g, this device is pretty heavy, but as it gives you all the benefits, such as wireless charging, that weight is only to be expected.

The finish is matt and rubberised, which makes it very easy to grip. However, it also gets dirty easily as stuff gets stuck in the rubber and is tricky to remove.

The Mophie is the most expensive of all the powerbanks we looked at in this test. In terms of price, it’s a lot more than the cheapest models and a fair way above the average. But it does offer more modern features. Wireless charging isn’t common yet and it also charges quickly via cable. If you want to spend extra money on wireless charging, we don’t think it’s too expensive. All in all, the Mophie does a fantastic job.

Wireless chargingfast charging of phone batteries
High pricelong charging time for the powerbank itself

Price Comparison

Compare all prices
Amazon.co.uk Logotype

mophie 6000 mAh PowerStation Quick Charge External Battery - Space Grey

£19.20
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Mophie Powerstation XL - Blue

£20.00
Computers Deal Logotype

mophie Powerstation XL power bank 10000 mAh Black, Grey

£28.08

2. GP Powerbank Voyage 2

Colourful and fast charging

Volts: 5.11 A: 0.94 Operating time: 6.16 hrs Charges: 2.82 Charging: 4 h 30 min Power: 4.80 Watts Ports: 2 x USB ports and 1 x type C port, plus 1 USB C charging port. Weight: 245 g Dimensions: 135 x 70 x 13 mm

GP Batteries PowerBank Voyage 2 10000mAh

The 10,000 mAh GP Powerbank Voyage 2 is a brightly coloured bit of kit. If you opt for the bright orange version, it’s a real eye-catcher, and one that’s hard to lose track of in deep bags or dark environments. The same model is also available in a plethora of other colours, some of which are equally bright and which help give the GP Powerbank an identity many others lack.

In terms of charging itself, the powerbank is full in just 4 hours and 30 minutes, which is pretty fast. So if you’re off out camping and you’re in a hurry to maximise the powerbank's batteries, this could well be the choice for you.

The Powerbank Voyage 2 also has two USB ports and a USB-C port for charging devices, as well as USB-C port for charging the powerbank, all of which together form quite an impressive setup. This makes it competitive even though it takes longer to charge your devices.

Fantastic charging timelots of portshard to misplace the brightly coloured version
Slow charging of devices

3. Anker Powercore

The smallest powerbank with the fastest charge

Volts: 5.15 A: 1.62 Operating time: 3.55 hrs Charges: 2.79 Charging: 5 h 30 min Power: 8.34 Watts Ports: 1 x USB port for charging 1 x Micro-USB for charging Weight: 180 g Dimensions: 92 x 60 x 22 mm

Anker PowerCore 10000mAh

If you’re looking for a powerbank that’s small but charges quickly, the 10,000 mAh Anker Powercore could be the ideal choice. With an operating time of 3 hours and 33 minutes and offering 2.79 charges per unit, it’s without a doubt the fastest in our test. These great results can be attributed to its QI 3.0 function. Though of course that also means your other equipment needs to be able to support the QI technology.

With a weight of only 180 g, which is among the lightest you can find in this class, and a length of only 9.2 centimetres, it’s both lightweight and easy to fit into your bag or pocket and carry around.

Unfortunately, for charging the powerbank, you only get one USB port and one Micro-USB. In other words, you’re limited to charging one device at a time.

With a powerbank charging time of just 5 hours and 30 minutes, this is also one of the fastest when it comes to charging itself, which makes it a solid competitor.

Anker's black design works very well, although it’s sensitive to stuff like greasy fingerprints, for example, which can make it look shabby pretty quickly.

Fast charging of devicessmalllight weight
Gets dirty easilyfew portsexpensive

4. Xiaomi MI Powerbank 3

Heavy but convenient

Volts: 4.94 A: 1.41 Operating time: 4 hrs 15 min Charges: 2.91 Charging: 6 hrs Power: 6.97 Watts Ports: 2 x USB ports, 1 x type C port, 1 x micro USB Weight: 282 g Dimensions: 148 x 75 x 15 mm

Xiaomi Power Bank 3 10000mAh

At 10,000 mAh, the Xiaomi MI Powerbank 3 is among the most efficient powerbanks we tested in terms of the number of times you can charge your phone before the charge in the powerbank itself runs out. The slim, elongated shape makes it easy to store the Xiaomi in narrow pockets or small spaces. The operating time is 4 hours and 15 minutes so the unit charges mobile phones and similar devices quickly and efficiently. However, charging the powerbank itself takes around 6 hours for a full charge, which is relatively slow.

The MI Powerbank 3 comes with two USB ports, a USB-C port and a Micro USB port, which together will cover most needs. However, it does weigh a fair bit. At 282 g, the Xiaomi powerbank is one of the heaviest in this class.

Good number of chargesfast charging of mobilesslim design
Heavyslow charging of powerbank itself

All about powerbanks

Every time a survey is carried out about what us consumers want in a mobile phone, "better battery life" is almost always the top answer.

And that’s not so surprising. Today's phones run through their charge in about a day – sometimes less if you use it a lot and sometimes more if you turn on power save mode. Many of us still remember old school mobile phones where standby time was measured in weeks rather than hours, but on the other hand those phones were largely used to just to make calls or send texts. A modern phone has more in common with a fully-featured computer in terms of what it can handle and has replaced everything from compact cameras to music players, and film viewers to web browsers. More functions, more capable hardware and, above all, much larger screens simply use more power.

If you know your phone has a problem lasting a whole day, or if you just want to avoid the stress of running out of battery, a powerbank can be a great investment. They are basically an extra battery that can be used to charge your phone when you don’t have access to a normal phone charger.

Powerbanks come in a range of different sizes. Just like the battery in today's phones, capacity is measured in milliampere hours – mAh. A normal phone today has a battery of between about 2,000 and 4,000 mAh, and powerbanks usually start at just over 2,000 mAh and go all the way up to 20,000 or even 30,000 mAh.

Smaller capacity means a smaller battery inside the powerbank, and thus a smaller size overall. Smaller batteries generally take less time to charge. At the same time, of course, you want to be able to both fully charge an almost discharged phone and for it to be fairly quick even if you're using the phone at the same time. So powerbanks with a slightly larger capacity are often better.

At the same time, powerbank mathematics isn’t entirely straightforward. Say you have a phone with a 2,000 mAh battery, that doesn’t mean that an equally large powerbank can fully charge the phone once. Depending on how the powerbank's electronics are structured, the current loss can vary. You simply always ‘waste’ some current during charging. If the phone is being used at the same time, it constantly draws power, which also affects the amount of charge.

In our test, we looked at powerbanks with a capacity of around 10,000 mAh. These are still relatively small and flexible devices, yet they also have the capacity to fully charge a phone at least once, and often twice. It’s also in this class of powerbank that extra functions start to appear, such as fast charging, the ability to charge two devices at the same time or even wireless charging.

Everything you need to know about powerbanks

What is a powerbank?

A powerbank is a battery backup designed to store energy for charging mobile phones, laptops,etc. Inside a powerbank there’s usually one (or more) small lithium batteries that store the energy.

How do you charge a powerbank? How long does it take?

Charging a powerbank takes different lengths of time depending on how much energy the lithium batteries can hold. You charge the powerbank via a standard USB port such as USB-C, micro USB or USB-A.

Charging time also depends on how much current the powerbank can accept, and how powerful the charger for the battery pack is. So there are quite a few factors at work. In the test above, you see the differences in charging time with a standard mobile charger and powerbanks of approximately 10,000 mAh

How big a powerbank do I need?

How big a powerbank you need depends on what you want to charge. For example, if you have a powerbank of 10,000 mAh, that’s going to be enough for about 2-4 charges of a mobile phone or one charge for an iPad. If you need more than that, you can even buy powerbanks with a capacity of 20,000 mAh or more.

There are also smaller capacity powerbanks, usually from around 2,500 mAh up to about 5,500 mAh. These are generally cheaper and smaller in size. But while they’re able to charge a phone, they may not give it a full charge, and so are used mainly as an emergency charger or to top up the battery a bit.

What ports do powerbanks have?

Generally, there are three types of port found on powerbanks. All three won’t be on all powerbanks, but at least two of them will be.

USB-A: An ordinary USB connector. Simply plug in your normal charging cable and charge up your phone. • Micro USB: A small semi-oval connector of the kind that slightly older mobile phones are charged with. Used almost exclusively to charge your powerbank. • USB-C: A newer sort of USB connector that will eventually replace all other types. An oval shape that can be plugged in any direction and still work. It’s usually via this sort of connector that you get a slightly stronger charging current. In many cases, the connector can be used both to charge your phone and to charge the powerbank itself.

There are also some powerbanks that have built-in cables. The most common is a Lightning connector, i.e. one that you charge an iPhone with. There are also variants with USB-C or micro USB, or several cables built into one. This solution is convenient because it means you don’t have to remember to bring a separate cable. At the same time, such cables are usually quite short and if the cable breaks you can’t use the powerbank.

What is fast charging?

Waiting for a device to charge is kind of boring, so we want it to happen as quickly as possible. To do that without damaging your equipment, a lot of fast charging techniques have been developed.

Many manufacturers have their own fast-charge solution, which often requires you to use their devices throughout. However, there are a couple of more universal solutions.

Qualcomm Quickcharge in versions 1.0, 2.0 or 3.0 is a variant that’s quite common on powerbanks. Qualcomm provides a faster charge of your device, but does require your phone or tablet to support the technology. In practice, this means you must remember whether or not your system chip (the chip with the processor, RAM, graphics and so on) in your phone is manufactured by Qualcomm. If you have a Qualcomm Snapdragon chip in your phone, then it’s almost certain to support one of the Quickcharge technologies (the later the version, the faster the charge).

Fortunately, in Europe, Qualcomm is pretty widespread. With the exception of iPhones, Huawei's phones and Samsung's flagship models, Snapdragon chips are actually found in most phones sold here. But if you’re unsure, check the manufacturer's website for your particular model.

USB Power Delivery or USB-PD is a slightly more general standard that almost all phones, tablets and even laptops with USB-C can support. This is also becoming more common on powerbanks and will probably become fairly standard over time.

USB-PD works via a USB-C connector and even though it’s not very complicated, we may as well start from the basics.

USB-C is both the connector and the standard for how it’s designed. However, there are a plethora of techniques that can use this type of connector, from USB 2.0 up to USB 4.0, Thunderbolt and so on. This means it’s quite complicated when it comes to data transfer speeds, which devices are capable of running an external monitor and so on.

The USB-C contact standard, on the other hand, is essentially designed to handle significantly greater power than previous micro USB and the like, and this is where Power Delivery comes in. The transmitter (the powerbank, in this case) and the receiver (the mobile phone), "talk" to each other and can decide how much the receiver can accept.

This means the device can be charged with anything between 5 and 20 volts and with outputs of up to 60 watts (100 watts with a special cable). Everything from the 0.5 A that USB 2.0 can handle up to 5 A is supported.

To put it simply: In the past (USB 2.0), all mobile batteries received the same portion of food (5 V, 0.5 A) no matter what. It could be bypassed with Quickcharge and similar manufacturer-specific technologies, but in practice that was what phones got. With USB-PD, each phone can get exactly the right amount of food they need and can handle, i.e. more energy in less time.

How do solar cells and crank charging work?

Crank charging and solar cell charging are of interest to many people. And crank charging is quite easy to understand. You crank up a small motor inside the powerbank, which in turn generates energy and charges the power bank without having any external access to electricity. It takes a couple of minutes of cranking to get a few percent of battery power, but it can save your day. So the principle is exactly the same as for radios with a crank function, but here you’re charging your phone.

Solar cell charging is a more efficient way and around 10 hours of sun can fully charge a powerbank of about 8,000 mAh. Of course that depends on both the weather and the solar cell. So it’s always faster and more reliable to charge via the wall outlet when you can.

Is a powerbank already charged when I buy it?

They usually have a little charge in them but are rarely fully charged. A powerbank releases energy over time, so the battery level when you buy it will be linked to when it was manufactured and how long it’s been in stock.

You may be lucky and get about half capacity right out of the box but, on the other hand, you might get a lot less.

What are the rules for powerbanks on planes?

You can fly with a maximum of 100 WH (watt hours). You can calculate what this corresponds to for your own powerbank. Calculate it as follows: mAh (milliamperehour) x V (voltage)/1000.

This may not mean much to you and it can be tricky to keep work out, especially since a powerbank's capacity is calculated in milliampere hours rather than watt hours.

In general, however, you’re fine with powerbanks up to approximately 25-26,000 mAh, but any that exceed 30,000 mAh are often too powerful to be allowed on flights.

Do any powerbanks offer wireless charging?

QI is a version of wireless charging which is becoming more common. Most QI is aimed at mobile phones, as laptops and the like have batteries too big for it to be worth using QI. What you should also keep in mind if you’re interested in QI is that you have to know your mobile specs, as for example, QI can’t go through metal, so if you have metal on the back of your phone it won’t work.

Can I charge a computer with a powerbank? What do I need?

In theory, you can charge a computer with a powerbank, but what you should remember is that the computer's battery is much larger than a regular battery for mobile phones and so requires more power, so if you want one to charge your PC, you need to invest in a larger and much more powerful powerbank.

It’s also important that the powerbank is able to deliver more current than a normal mobile phone needs. Here the output power is measured in watts (W) and you need roughly at least 20-30 watts out for many computers to even get a hint of a charge.

So if you need to charge a computer via a powerbank, be sure to buy one specifically designed for doing that. They’re bigger and heavier, but as a bonus you can also charge your phone with them.

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