Best portable power bank chargers
Even the most impressive smartphones struggle to last more than a couple of days, and battery technology is fighting a never-ending battle against the latest and greatest power-draining features.
It’s no surprise, then, that power banks – or portable phone chargers – have become one of the most popular must-have accessories for smartphones. Available in all shapes and sizes, they vary from ultra-portable chargers designed to offer a quick boost, to large and arguably cumbersome alternatives that claim to fully charge a handset multiple times.
If you've used a power bank before you might agree that what’s promised on the box – often one or more ‘full-phone’ charges – is actually quite far from the truth. We decided to put this to the test, and have collected a range of power banks from some of the most popular brands to find out if they really deliver what they promise.
Before buying a portable charger, it's important to know what to look for.
Battery capacity is measured in milliamp hours – or mAh. The larger the number, the more charge a battery can (supposedly) hold. Like mobile phone batteries, power banks are measured in mAh, so you’d be forgiven for thinking that if you have a power bank that’s the same capacity as your phone battery, it’d give it a full charge. In practice, we found this to be far from clear cut.
In our results tables below, we’ve split the power banks we trialled into three categories. Low capacity (less than 5,000mAh), medium capacity (between 5,000 and 9,999mAh) and high-capacity (more than 10,000mAh).
By charging a series of mobile phones, we worked out the percentage of charge that each power bank delivered against its claim – obviously, the higher this is, the better. This percentage should only be taken as an approximation of the charge available in a power bank – additional factors mean this could vary based on the make and model of phone, and how it's charged, but it is a useful comparable measure.
Read on to find out more about each type and which performed best. We've also highlighted our top pick in each category, which may not always be the power bank that delivered the highest percentage charge.
Low-capacity power banks
Low-capacity power banks can be ideal emergency options - especially if you want something small enough to carry around in a pocket or bag. You’ll often miss out on some useful additional features with smaller power banks – such as multiple USB ports to charge more than one device at a time, and multiple LED indicator lights, which can be useful to tell at a glance how much power is left.
Low-capacity power banks also tend to be pretty cheap, so it won't cost much to have one of these safely tucked away, ready for an emergency situation.
Browse the table below to see how a range of low capacity power banks compared.
Medium-capacity power banks
If you'll be away from a power source for a longer period of time, are planning fairly extended use of your phone or want a few added extras such as multiple device charging, some medium-capacity power banks can tick the boxes. The advantage here is that you’re getting more features and (in theory) more power, with a device that's still fairly portable and easy to carry around.
Medium-capacity power banks can still be picked up fairly cheaply and, in some cases, for a lower price than low-capacity models.
Browse the table below to see how a range of medium capacity power banks compared.
High-capacity power banks
If you're looking for a charging solution that will get you through an extended period without a regular power source, or perhaps want a single product to share amongst the whole family, a high capacity power bank could do the job. These models are commonly available with capacities in excess of 10,000mAh, which on paper at least, should mean they're capable of fully charging many smartphones over three times.
The main downside of these models is size – they can be quite large and heavy, so aren’t really suitable for pockets or carrying around comfortably if you’re looking to travel light. You’ll often find dual USB ports, though, which means you can charge two devices at once, and multiple LED indicators are particularly useful here – providing they're accurate.
Browse the table below to see how a range of large-capacity power banks compared.
Which power bank is best for you?
While the pros and cons of different makes and models of power bank do vary, overall the results of our first looks showed a very clear trend. We found certain categories of power banks to be, on average, significantly less able to deliver on their promised capacity than others.
The difference between specific models can vary even more dramatically. The best on test delivered 86% of its stated charge, whereas the worst was just 54%.
Another point worth noting is the time taken to charge. This varied considerably, with the longest taking up to eight-and-a-half hours, so you really need to plan in advance.