It looks metallic, but the case is actually made of plastic polycarbonate, which houses the lightweight lithium-ion polymer battery cells that power it. Again, it has two USB ports, one that has a 2.4A amperage, and one 2A, and four LED indicators that show the battery level.

power banks for charging on the go - The Telegraph The best power banks for charging on the go - The Telegraph

Includes: Charging cable (USB-A to USB-C), 20cm 1 x USB-C - PD3.0 18W max input and output 1 x USB-A – 18W max output Another point of difference which makes the Moshi IonSlim 10k stand out as are the battery's lithium-polymer cells, which have no ‘memory effect’ (an effect observed in some rechargeable batteries that causes them to hold less charge over time, because the battery appears to "remember" a smaller capacity). You can charge the IonSlim as frequently as you wish; it should stand the test of time.There is a button which actually works to turn the device Off. And a Fast charging indicator light. Wise deployment of airplane mode – when you're watching a set, sleeping or charging – will go a long way. With 20,000mAh of juice in the bank, you can charge an iPhone 7 6.5 times over, an iPad Mini 4 2.5 times over, a Galaxy S8 4.3 times over, and an LG G6 3.9 times over. By my count, that's the whole family catered for with more to spare. Similar to the Juice Power Station, it also has an LED charging gauge so you can easily judge how charged up it is. Why isn't in our top three? Well, it's an ugly, clunky thing, truth be told, and it feels a little heavy. That said, I’ve long been a fan of Griffin accessories due to their impressive durability (particularly their phone cases); in general, it's a company you can trust. Why we like it: It's colourful, compact, powerful enough to fuel a long weekend away, and very reasonably priced. Good for teens and their parents.

Duracell 20,100 mAh Fast Charge Portable Power Bank Duracell 20,100 mAh Fast Charge Portable Power Bank

It takes around three hours to charge from empty (considerably less time than the Juice Power Station), and once charged, Belkin says its tests show that charge will not diminish by more than 50pc even after a year’s time left dormant – all very impressive, and useful.And that's basically what I did. The power bank came in handy when trying to locate a friend to meet for a swim on Hampstead Heath (my phone was on its last legs – isn't it always?), and during last ditch attempts to keep my nieces and nephews entertained with games on long journeys (there’s only so much I Spy any sane adult can handle). Why we like it: The Daddy of the power banks we reviewed. Powerful, well designed, not too heavy, and brilliantly priced.