When used as an input it means you can refill this power bank in as little as four hours, and as an output it’s meatier than many we’ve seen. The majority tend to offer around 30W, but at 45W this Zendure matches the Dodocool 20100mAh PD charger currently riding high in our best laptop power banks chart. That’s important, because not all USB-C laptops require the same amount of power, and 30W banks are typically compatible only with the USB-C MacBook. (Check the spec of your current laptop charger to be sure.) Built from an ABS/PC Composite, the A6PD has the same rugged build as previous power banks in Zendure’s line-up. It used to market these devices as tough enough to run over in a McClaren, and though that no longer seems to be something it shouts about the A6PD certainly seems as if it would stand up to that amount of force.  Our review sample is a gloss black, though it’s also available in silver. It has a ribbed exterior that has always reminded us a little of a Pelican case, significantly aiding grip in the hand. The single button has been moved from the familiar front position to the power bank’s side, where it also sits with four LEDs used to show how much power remains. We’d rather see an LCD screen for an exact readout as this capacity, but we can’t complain. So how much exactly is 20100mAh in the real world? Zendure stands out among power bank manufacturers for its 80 percent energy efficiency rating, where most others can support only up to 70 percent. Its devices will also hold that charge for up to six months. This means you could see as much as 16000mAh available to your devices. As a rough guide, Zendure suggests you’ll easily be able to charge your MacBook 1.5 times, iPhone X 5.5 times or Nintendo Switch 2.5 times. And yet it’s not overly big and heavy at 162×78.5×22.5mm and 370g. You won’t necessarily use this Zendure to charge only one device, of course. It actually has two inputs and two outputs, though you’ll see three ports on one end of the bank (this is because the USB-C port is both input and output). We’ve already raved about the 45W USB-C port, but the full-size USB-A is pretty impressive, too. It can fast-charge at up to 18W, which is Quick Charge 3.0 speed. Pleasingly, the Zendure can support both outputs at max speed at once. The second is a Micro-USB, faster than many at 12W, but no match for the USB-C port for refilling this bank. When it does come to recharging the Zendure you’ll find you can do so while charging a connected device. This is a process known as Charge-through or passthrough charging, and allows you to use a single mains outlet for charging multiple devices. It’s very handy. Zendure supplies a USB-A- to USB-C cable and a cloth carry case in the box. 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.