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 smartphone, tablet or other USB-powered device, you need a power bank. Also see: How to charge your smartphone or tablet faster.
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, but some of the best can offer 90 percent efficiency.
We’re seeing an increasing number of power banks with support for Quick Charge 4.0 and USB-C, 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. Power banks may offer these in place of or alongside full-size USB, Micro-USB and Lightning ports.
We’re starting to see power banks that feature an AC/DC outlet (a plug socket for non-USB devices). Unfortunately many offer only a US two-pin plug, so you may need to carry an adaptor.
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.
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 waterproof or simply rainproof.
Nearly all power banks use LEDs to show you how much power remains in the device. This is fine for smaller-capacity devices, but when each LED represents several charges for your phone it can be difficult to see where you are. We favour banks with built-in LCDs.
Passthrough charging is a great feature to have – the ability to charge a connected smartphone at the same time as the device itself.
Auto-on and auto-off is another sought after feature, though sometimes a bank can support this and your phone won’t. It means you can plug in a device and the power bank will begin charging without you pressing any buttons. When charging is complete it will put itself into standby mode to conserve energy.
Some power banks also come with an LED torch, activated by double-pressing the power button.
Get the fastest charging rates
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.
Don’t expect to get a USB charger in the box – you can use that which was supplied with your phone or tablet. Note 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) or 2.5A (12.5W) outputs.
You can use either output to charge any USB device – it will draw only the power it needs. However, you might find some tablets will refuse to charge from lower-specified outputs.
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.
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.
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.
Best power banks 2017 UK – best power bank reviews
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.
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.
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 CHJGD UltraCompact Power Bank review.
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.
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.
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.
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.
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.
Zendure A8 QC
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.