Also see: Best Black Friday Gadget Deals A gunmetal grey thin plastic slab, the Iceworks power bank is a similar shape to a smartphone, and at just 8mm thick and 90g it’s very comfortable to hold behind your phone as it charges. In common with the Flux Card Portable Charger we recently reviewed it has two built-in cables with Micro-USB and Lightning connectors that clip into its side. This makes it significantly more portable than most power banks, with no need to carry around extra cables for charging your devices. Also see: How to charge your phone’s battery faster We were pleased to learn this Lightning cable is Apple-certified, which means it won’t stop working when Apple releases iOS 10 next month. Although it’s built from plastic, the Iceworks feels durable and well made. There is no carry case supplied, but even if there were we probably wouldn’t use it. See all power bank reviews As is the standard for power banks, four LEDs are used to indicate how much charge remains in the bank. However, here these sit inside a blue strip that spans the width of the power bank, giving it that extra something that stops it becoming just another bland plastic power bank. The Iceworks has a 5000mAh capacity, but that doesn’t mean you’ll have 5000mAh of juice available to your mobile devices. All power banks lose some of that capacity through heat generated and voltage conversion, and the industry-standard efficiency sits somewhere around 65 percent. Even so, you’ll be able to fully charge any Android phone, and get near on two full charges for an iPhone. Also see: How to improve smartphone battery life If you’re stuck choosing between the Iceworks and the aforementioned Flux, this power bank has a higher capacity and a lower price when you factor in shipping costs. Reasons to choose the Flux include its more compact metal build and faster connections. Whereas the Flux supports a 10.5W Micro-USB output and 7.5W Micro-USB input, this Iceworks has an only slightly lower 10W output but just a 5W input. This means it will take a full six- to seven hours to recharge from empty. Fortunately, like the Flux it supports passthrough charging, which means you can charge both it and a connected device from a single mains power outlet. Also see: Best MiFi 2016 While it doesn’t support the latest Quick Charge or USB-C technology, the Iceworks 5000 excels as a truly portable, good-value power bank. Read next: Best desktop chargers 2016. Follow Marie Brewis on Twitter. 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.