An Oxford-based startup has turned to crowdfunding to help develop Zap&Go;, a phone charger with an emphasis on speed and portability. Thanks to a graphene supercapacitor and an ad-hoc power supply, the device will reportedly charge to its 1,500-mAh capacity – enough to fully charge an iPhone 5s – in only five minutes and promises to be a much more practical solution than current alternatives, particularly when traveling.

Our smartphones and tablets keep getting thinner, while displays keep getting more pixel-dense and power-hungry. As a consequence, the battery life of our portable devices rarely exceeds one day of heavy usage. In addition, the limitations of lithium-ion batteries mean that these devices can take hours to fully charge. For those who need more juice on the go, one solution is to use an external battery that can recharge our electronics when needed, even when we're miles away from a plug.

Plenty of fast external batteries are already either on the market or on the horizon. Perhaps two of the most interesting projects currently in the works are the 2,600-mAh Petalite Flux and the Power Practical Pronto, which according to its inventors will also come in a 13,500-mAh version.

But for all their capacity and convenience, these external batteries require bulky adapters that add to the clutter, making them unpractical to pack in your suitcase while you're traveling; and while they charge significantly faster than your typical smartphone, they still take 30 to 60 minutes to fully load up.

The device is 40 to 50 mm (1.6 to 2 in) in diameter and doesn't require extra adapters

By contrast, Zap&Go; is designed specifically for speed and portability, as it can charge in just five minutes and doesn't require extra adapters, since the specially-developed power supply is embedded in the device itself. According to the product's Indiegogo campaign page, the device can charge any type of phone or tablet that comes with a standard 5-volt USB port.

You can use the Zap&Go; as a normal charger, plugging it into an electrical socket while your phone or tablet is charging normally and the device is completing its fast five-minute charge cycle; or, if you're pressed for time, you can just plug in the device for a quick and full charge-up, and only later, while you're on the go, connect the Zap&Go; to your device and have it charge (either way, the phone or tablet itself will still charge at normal speed).

The product, currently at a working prototype stage according to company founder Stephen Voller, required two major innovations: the first was to replace aluminum foils in supercapacitors with the much more conductive graphene, allowing the device to significantly shrink in size; the second was a new power supply to allow the charger to take in enough power in a limited amount of time.

According to the product's Indiegogo campaign, the Zap&Go; is set to be delivered in October 2015 for a pledge of US$99 and will ship with a US plug as standard, but will also include international plug adapters for the UK, Japan and the EU. At the time of writing, the Indiegogo campaign is one third of the way toward reaching its funding goal of $30,000, with 30 days still to go.

The video below shows the Zap&Go; in action.

Sources: Indiegogo, Zap&Go;