Unlike the larger 10,000mAh Omaker S-X5 power bank we’ve reviewed previously, this smaller 5200mAh model is the perfect size for your pocket, just 46x25x100mm and 118g. A soft carry case is provided, but the soft-touch rubber casing doesn’t feel as though it needs much in the way of protection. We like the design, a smooth almost pebble-like block of grey or yellow coloured plastic with two sheets of black rubber that wrap around the front and back, creating a groove at each side that makes the Omaker power bank easy to grip. We reviewed the yellow version, but suspect the grey may look a little more premium. Also see: Best MiFi 2016. There’s just one output on the Omaker Power Bank 5200mAh, but it’s a fast one, rated at 10.5W. This will charge your phone twice as fast as some phone chargers, and it’s powerful enough to charge a tablet too. Also see: How to improve smartphone battery life. If there’s enough power in the bank, that is – rated at 5200mAh and allowing for around 30 percent loss through voltage conversion and heat generated, you can expect about 3640mAh to be available to your devices. How many times that will charge your phone depends on the capacity of its own battery – it might charge an iPhone twice, but many Android phones just one and a half times. Once the power bank’s charge is depleted, there’s a 5W Micro-USB input for refilling it. As is standard with power banks, no charger is provided in the box, but you can use the one that came with your phone or tablet. It could take up to six hours to completely fill the battery. Also see: How to charge your phone or tablet faster. How much capacity remains is instantly visible by a row of four LEDs that glow blue when the power bank is in use. Each light represents 25 percent of the battery. Also see: Best desktop chargers 2015. 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.