When we review a power bank we take into account several factors besides the price: its build quality and appearance, how fast it can charge your phone, how fast it can refill its own battery (and whether it can charge both your phone and itself at once), how many times it will charge a device and so forth. The Lumsing performs well on most of these things. Let’s start with why you might choose this power bank. The 13,400mAh capacity is appealing, and should offer around 9,000mAh for charging your mobile devices. That would refill almost any Android phone at least three times, and for iPhones you’re looking at more like five or six full charges. Given that this compact 98x79x22, 263g power bank will fit in your pocket, that’s not at all bad. Also see: How to charge your phone’s battery faster More interesting to us, though, is its support for Quick Charge 3.0 and USB-C. Although Quick Charge 4.0 has recently been announced, right now Quick Charge 3.0 is the fastest you’ll find in a power bank – but it isn’t supported by all mobile devices. If you have a flagship smartphone running a Snapdragon processor, such as the LG G5, chances are your phone will support Quick Charge 3.0 and can therefore be charged four times faster than via a conventional charger. In addition to this full-size Quick Charge 3.0 port (which is confusingly labelled as QC 2.0/QC 3.0 when all Quick Charge 3.0 devices are backwards-compatible with Quick Charge 2.0) is a USB-C connection, which can act as both input and output at a fast 5V/3.1A. Using this connection this high-capacity power bank can be recharged in as little as 5.5 hours. That would be even more impressive if it could simultaneously charge your phone to cut down on cable clutter and free up mains power outlets in your home. We like having the option to charge a second device from this power bank, but not that it has to be a USB-C device. See all power bank reviews The USB-C input/output offers the fastest way to recharge this power bank, but a USB-C cable is not provided in the box and you’re unlikely to have one to hand unless you own a USB-C phone. Fortunately there’s an also fast – albeit not quite as fast – Micro-USB input that accepts 5V/2.5A. Charging the Lumsing over this connection will take longer, but in all honesty at this capacity you’ll likely just leave it plugged in overnight in any case. Another perk of the Lumsing Grand A2 Plus is auto-on. There is an orange button on the side of this power bank, but you don’t need to press it in order to begin charging – you just plug in a phone or tablet and charging begins. Rather, this button is used to invoke the built-in LED flashlight or to check how much power remains via the four blue LEDs on the device’s front. And here’s where things start to be less exemplary. The LED torch is so small that you wonder why Lumsing bothered to include one – we certainly can’t see anyone making use of it. Also see: How to improve smartphone battery life The Lumsing isn’t a bad-looking power bank, encased in matt black plastic with a brightly colour orange rim at the top and bottom, but we’re less keen on the high-gloss plastic end caps with idiot-proof legends. We don’t need to be told on the product itself that the ports are inputs or outputs, nor whether they are Type-C or support Quick Charge 2.0 or Quick Charge 3.0, especially when the specifications are also printed on the bottom of the device. To be fair this is a criticism we could level at many a cheap power bank, but it does detract from the overall design. The Lumsing is a functional device, and we like the amount of speed it offers, but if you pay just a little more you’ll get features such as the aforementioned passthrough charging, the ability to take advantage of multiple outputs without having a USB-C device, and a more premium overall design. The best power banks at this capacity might also offer an LCD screen for a more accurate representation of how much power remains. 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.