How to charge your iPhone (or iPad) faster | How to fix a MacBook that won't charge up

Broken iPhone charger fixes and tips: How to repair a broken cable

Unfortunately Apple's Lightning cables, and before them the older 30-pin connectors, do tend to fray and weaken at the point where the port meets the cable. It seems that the cable just gets twisted here, and over time the plastic coating wears out. In our case we twisted gaffer tape around the top to reinforce it.
If it's starting to weaken and wear away then a similar pre-emptive measure may help to ensure that it lasts a bit longer before giving way. But if you've got to the point where the cable stops working, more drastic measures may be required.

It is possible to repair the wiring of a Lightning to USB cable if you're a dab hand with a soldering iron. It's not a particularly easy process, however, and we'd be tempted to just pay the £15 to replace the Lightning to USB cable (you can spend an extra £10 and get the 2-metre version instead of 1-metre).