Let’s start with the obvious: at 69x69x146mm this power bank isn’t going to fit in anyone’s pocket. RavPower instead supplies a soft mesh case for carrying the power bank and necessary cables, plus a tough zip-up case that can hold it and the required external DC charger (you don’t use Micro-USB to refill this portable charger). We also found a carabiner clip in the box, which can be attached to the strap on the case. There are two reasons for its size: first, it is a huge capacity 20,100mAh (74.37Wh) power bank with enough juice to fill an iPhone 7 six times, a Galaxy S7 4.5 times, or even a 12in MacBook 1.3 times; second, there’s lots of clever charging tech inside. Also see: How to charge your phone’s battery faster. The key difference between this power bank and those that cost a fifth of the RavPower’s price is the 65W three-pin AC outlet and 19V/1.6A DC input. It might have a huge capacity, but over the DC input it will charge in just four hours. By comparison a standard power bank of this capacity would take at least 10 hours to refill. Meanwhile, the plug socket on top lets you plug in and power anything from drones and action cameras to printers and laptops, provided they draw less than 65W. Powering a drone is an ideal use for the RavPower PowerStation Series. There’s loads of fun to be had with these gadgets, but using one often requires going away from home, which is when you discover the batteries pack up far too quickly. With the RavPower you can play a while longer. Also see: How to improve smartphone battery life. This is the second 65W AC/DC power bank we’ve reviewed – also see our Omnicharge review, a similarly priced Indiegogo project that comes with a very useful LCD information screen – but the first to come with a UK three-pin plug. An adaptor is also supplied in the box if you live or will be using the RavPower outside the UK. You can also buy 100W AC/DC power banks, but expect these to cost more. The AC outlet is an emerging technology for power banks, but currently priced out of many people’s budgets. That’s a shame, because with it a power bank is able to do a lot more than power a phone, tablet, smartwatch, camera or USB-C laptop. An AC outlet can be used for any type of device with a plug, but when it comes to devices that charge over USB carrying a simple cable is much more appealing than an entire power supply. For phones, tablets and other USB gadgets there are two USB outputs: one USB-C, which runs at 5V/3A, and one 5V/2.4A iSmart USB output. Slightly disappointing is the fact the two cables supplied in the box are both USB- to Micro-USB and not USB- to USB-C or USB-C to USB-C. There’s no support for Quick Charge but both are fast-charging ports, with the iSmart output able tor recognise the type of device plugged in and deliver only so much power as it requires. Also see: What is Quick Charge? To switch from USB power to the AC outlet you simply press and hold the power button for three seconds to turn it on. This power button can also be tapped to show how full is the power bank, with five LEDs in a strip around its belly each representing 20 percent, or 4,020mAh. In reality it’s not quite 4,020mAh, because not all of that 20,100mAh is available to your devices. Some energy is always lost through heat and voltage conversion, and the industry-standard efficiency rating is around 65 percent. We have seen power banks that go as high as 90 percent, such as the aforementioned Omnicharge, but the RavPower is not one of them. This means that despite its lower 13,600mAh capacity, there is very little difference in the usable capacity of the Omnicharge and the RavPower. It also means that with a larger battery the RavPower is a bigger and less easily portable device. Also see: Best MiFi 2017. Despite its size, we prefer the RavPower’s tall, cylindrical, Red Dot Design award-winning design. The soft-touch rubbery finish and rounded corners make it seem less unwieldy and prone to damage, while the plastic strip running around its middle that holds its LEDs is a nice touch. We also like the fact the AC outlet is covered to prevent dust getting in (this is exposed on the Omnicharge), and the inclusion of small vents running around the top and bottom for improved heat dissipation. Plus you get the usual overcharge-, short circuit- and current surge protection built-in. The tough carry case is a very welcome inclusion given the rather bulky power supply, but we don’t think you need it for anything other than keeping together the RavPower and its accessories. It has a partly plastic construction, but it feels as tough as any metal power bank. Should you require it the PowerStation comes with an 18-month warranty, with a card in the box (at least with our sample) offering to extend this to 30 months for free. Particularly reassuring when you’re spending this much on a power bank. Read next: Best desktop chargers Marie is Editor in Chief of Tech Advisor and Macworld. A Journalism graduate from the London College of Printing, she’s worked in tech media for more than 17 years, managing our English language, French and Spanish consumer editorial teams and leading on content strategy through Foundry’s transition from print, to digital, to online - and beyond.