The disadvantage to our phones doing so much for us these days is the battering the battery takes.

Apple’s latest iOS7 software keeps all your open apps updating in the background, for instance – useful, but arguably less so when your handset’s conked out 20 minutes after you’ve left the house.

The only answer it seems is to carry some back-up power. So far that’s meant either carting a spare battery pack around with you (a faff, and easy to forget) or investing in one of those chargeable external cases (fattens up your phone, looks ugly).

The Powercard, new out from US hi-fi company Monster, offers a simpler, smarter solution.

The same size as a credit card and not much thicker, it's designed to slip into your wallet so you always have it to hand. It comes in a whole bunch of colours, works on all phones and claims a charge time three times faster than using a regular USB. We’re sold.

£35.95