Zuo Charge
A Spanish firm has invented a cable accessory that allows one phone to charge another Zuo Charge

Have you ever been caught out with a dying smartphone and you've left your smartphone charger at home, or it's not working properly? Now it's possible for you to charge your phone off someone else's phone, as long as they have differing tastes in mobile devices to yours.

Zuo Charge is a tiny cable that sits on a keychain. It consists of a short £13 ($19, €17) wire fitted with a USB connector on one end and a Lightning connector on the other end that enables you to charge your smartphone off your friend's device, as long as they have a Samsung phone and you have an iPhone, or vice versa.

The solution works as long as both smartphones support USB On-The-Go (OTG), a specification that enables devices to switch back and forth between the roles of host and client. Put simply, OTG means a mobile phone can act as a host device to access data from a removable SD card inserted into it, but if the phone is plugged into a PC, it will then act as a removable USB mass storage device and the PC would become the host.

In addition to sharing power with someone else's device, the creators of Zuo Charge, who are based in Malaga, Spain, say that the cable allows you to charge your phone the usual way via USB from a laptop or desktop PC, or from a power point using a USB plug.

The concept of using a cable to share power with your friend, whose smartphone might be dying, is quite a novel concept, but the drawback of Zuo Charge is that both parties have to own different devices, so if all your friends and family have iPhones and iPads, or they all have Android devices, the cable will not work.

However, if you are caught out without a smartphone charger or a dying phone, the option to share power with a friend could be beneficial in an emergency situation, such as needing to call a cab to get home in the middle of the night.