What is it?

Hydrogen power on the move for your gadgets.

How will it change my life? We have all been there: that heart-sinking moment in a train station or an airport departure lounge when the public address system crackles into life to impart the bad news that your chosen mode of transportation is delayed.

Never mind, you think, at least I downloaded that film or a raft of social media sites will keep me amused. Then, bang on cue, the low battery icon starts blinking ominously. Inevitably, you spend the remaining moments feeling like Jack Bauer as the clock ticks down to zero.

Good points? The charger promises up to a week of clean power for your USB gadgets. With the cartridge in place, it weighs 600g and measures just over 20cm long by 4cm by 5cm, which is fairly svelte when you consider the longevity it provides.

The UPP is a prime example of user-friendly design. It is impressive to behold; in fact, the attention to detail is arguably over the top for a device that is likely to be hidden most of the time.

Operation is equally remarkable in its simplicity with the fuel cell and base unit coming together magnetically. There are no fiddly wires to connect or pins to line up, just the strong attraction of two perfectly fitting components making it impossible to get wrong.

The charging time in the manual is a little vague, so I used a timer and a half-powered mobile to test it. Each time I experimented, the battery app on the phone was registering 50 per cent and getting it to full charge took only 15 minutes. The accompanying phone app lets you track the energy consumption.

Bad points? The charger gives out an intermittent clicking sound not unlike the Geiger counters you see in disaster movies, which is a tad unsettling until you get used to it. The noise, coupled with a slightly odd smell I can't quite put my finger on, makes for an uncomfortable experience on first use, but the feeling is quickly forgotten with every lightning-fast charge of a USB device.

Best for … Anyone looking for a reliable, fast and portable power back-up. From that perspective, it is helpful peace of mind in an emergency. It would be equally handy for outdoors types.

Avoid if … You can't be bothered buying replacement cartridges, the price of which was unconfirmed as we want to press. Equally, those looking for a device small enough to slip into a pocket will be disappointed. While compact considering the huge power it offers, the charger is still bulky.

Score: 8/10.

l UPP Portable Charger, £149 (beupp.com)