Power banks are the saviour of the smartphone-addicted when away from the convenience of mains electricity. Thing is, if you’re off-grid and exploring there’s a good chance you’ll need to zap your talky box quickly. You know, like 5-hours-of-battery-life-in-5-minutes quick? Well, good news: STK’s fast fuel 15K (£50) does exactly that, boosting your mobile six times over (thanks to a 15000mAh capacity) with Quick Charge tech that’s four times as fast as your standard USB port. Better still, it’s clad in rubber for in-rucksack protection, while a pair of USB ports means you can share out the electrons - or boost your own barrage of devices.