Best USB power banks of 2017
Kiss flat batteries goodbye with these portable chargers
No matter which smartphone you own or how long you think its battery will last, Sod's law says that it will run out when you need it most. There's no need to worry though, if you're carrying a USB power bank.
These lifesavers are basically big batteries with a USB port so you can plug in any mobile device to quickly top up its charge. There are hundreds of different power banks available, including many suspect no-name bargain basement models.
Luckily, we've sifted through all the chaff for you. Our battery life tests not only show you which USB power banks last the longest, but which ones have the most useful features too.
When it comes to tech's no-frills essentials, the Amazon Basics range is hard to beat and the company's power banks are no exception. Available in seven different capacities from 2,000mAh all the way up to 16,100mAh, there's no fancy features on display here.
In fact, there's barely any features at all. There's just one USB port, along with four indicator lights to show what capacity the battery is at. It makes up for this, however, by being incredibly affordable, coming in at just 11 for the 5,600mAh model.
Amazon Basics key specs
|Extra battery life||13hrs 32mins|
|Size (WDH)||115 x 65 13mm|
Price when reviewed : 11
Cobra Jumpack CPP 8000
Cobra's latest USB power bank only' added an extra 24 and a half hours of extra usage to our test phone, but it has an additional trick up its sleeve. It also comes with jumper cables so you can jumpstart most cars with it too.
The CPP 8000 doesn't have the built-in flashlight of earlier models, but unlike its predecessors you can recharge it using a standard micro USB cable instead of having to use a proprietary power adapter.
If you're on the road a lot, this power pack could be a life saver in more ways than one.
Cobra Jumpack CPP 8000 key specs
|Extra battery life||24hrs 29mins|
|Size (WDH)||17 x 73 x 140mm|
Price when reviewed: 80
Enerplex Jumpr Slate 5K
This slender power pack is just thick enough to accommodate a full-size USB port and is similar in overall surface area to a pamphlet. A built-in tethered Lightning cable allows you to charge your iOS devices even if you've forgotten your usual lead a separate micro USB version is also available.
Due to its waif-like dimensions, it only added an extra 20 hours and 18 minutes of video playback time to our first-generation Moto G. Still, its lightweight and thinness means you should be able to fit it into all but the most crowded of bags and even some large coat pockets.
Enerplex Jumpr Slate 5K key specs
|Extra battery life||20hrs 18mins|
|Size (WDH)||251 x 127 x 28mm|
Price when reviewed: 70 from www.amazon.co.uk
PNY PowerPack HD 5000
PNY's sleek and glossy black power pack is one of the cheapest here, although it only added just over 19 hours of extra battery life to our test phone. It does have a handy light-up display though, showing exactly just how much battery charge is left. Plus it has two full-size USB ports, a 1A port for phones and a 2.1A port for tablets.
PNY PowerPack HD 5000 key specs
|Extra battery life||19hrs 02mins|
|Size (WDH)||118 x 61 x 13mm|
Price when reviewed: 22
PowerTraveller PowerMonkey Extreme
If you're a fan of both mobile gadgets and the outdoors, then you'll appreciate the PowerMonkey Extreme. This ruggedly made battery pack is water resistant with flaps protecting its various ports. This also means you can simply wash it down if it's grubby or just plain dusty.
A huge range of adapter cables are included in the box for antiquated feature-phones alongside the now standard micro USB lead as well as a rather bizarre multi-part lead necessary for charging the now discontinued iPad 4. It even comes with a solar panel for topping up its charge in the wilderness, but this is very much a measure of last resort as this can take a very long time to fully charge the PowerMonkey's huge battery.
You shouldn't need to do this too often though as it added 30 hours and 40 minutes of extra video playback time to our Moto G.
PowerTraveller PowerMonkey Extreme key specs
|Extra battery life||30 hours 40 minutes|
|Size (WDH)||152 x 89 x 28mm|
Price when reviewed: 60
Samsung External Battery Pack (11300mAh)
Samsung's chunky power bank is available in plain as well as animal-decorated versions. There is, unsurprisingly, a built-in retractable micro USB lead for charging your Android or Windows phone and a full-size USB port for everyone else. It didn't disappoint when it came to longevity, adding a staggering 47 hours of extra battery life when playing video on our Moto G.
Samsung External Battery Pack key specs
|Extra battery life||47 hours|
|Size (WDH)||74.5 x 116.9 x 22.9mm|
Price when reviewed: 40
Tylt Energi 12k
The only power bank that can rival Samsung's for sheer endurance was Tylt's thick and chunky Energi 12k which added an extraordinary 51 hours and 23 minutes of extra video playback time to our test phone. That's plenty of charge to go around, so there are three built-in full-size USB ports as well as a series of LED lights acting as a simple charge indicator.
Tylt Energi 12k key specs
|Extra battery life||51hrs 23mins|
|Size (WDH)||118 x 25 x 76mm|
Price when reviewed: 40
Tylt Energi 6k
Although this smaller Tylt power bank can't rival the Energi 12k for sheer longevity, managing just' 16 hours, it has other tricks up its sleeve. Not only does it have a built-in lead for connecting your phone (separate micro USB and Lightning versions are available), it has a built-in US plug with slimline UK and European adapters included in the box.
That means the Energi 6k is both a power bank and a wall charger in one, charging both its internal battery and your mobile device when plugged in. Genius.
Tylt Energi 6k key specs
|Extra battery life||16hrs 09mins|
|Size (WDH)||90 x 42 x 12mm|
Price when reviewed: 60