Next-generation iPhones likely to focus on internal improvements.
Unauthorized Third-Party Chargers May Damage iPhone 5 Charging Circuitry
According to UK repair company mendmyi and first reported by iMore, cheap third-party iPhone chargers and USB cables can possibly damage the U2 IC chip on the logic board of the iPhone 5, which might the device to fail to boot up or charge past 1% battery life after the battery drains.
The U2 IC chip controls the charge to the battery, the sleep/wake button, some USB functions, and regulates the charging power to the power IC that actually charges the phone. When damaged, the chip can fail to work properly, which prevents an iPhone 5 from turning back on. While a fresh replacement battery will power the iPhone, once the battery is depleted, the issue resurfaces.
Mendmyi says that it has seen multiple iPhone 5 devices with a damaged U2 IC chip and has narrowed the problem down to third-party chargers and USB cables, which do not properly regulate voltage.
The cause of this component becoming faulty is really quite simple -- third party chargers and USB leads!It is not clear if the issue is limited to the iPhone 5 as some users have also reported third-party charger issues with the iPhone 5c, which may use the same component, but the iPhone 5s and the iPhone 5 use different U2 IC components. Users with an iPhone 5 experiencing charging issues that have used a third-party cable may have damaged their devices, which will need to be repaired by Apple or another repair outlet.
The original Apple chargers and USB leads regulate the voltage and current to a level that protects your valuable iPhone and prevents it from damage.
Charging your iPhone using a third party charger or USB lead that does not regulate this as much allows for larger variables in voltage and current, this then damages the U2 IC and can leave you with a seemingly dead iPhone 5.
Apple has regularly recommended against using third-party chargers and cables. In mid-2013, the company even launched a third-party power adapter recycling program, following the electrocution of a Chinese woman allegedly caused by a counterfeit charger. Apple ran the recycling program from August to October of 2013, recycling counterfeit adapters and providing customers with a $10 credit towards an Apple-branded charger.
As of iOS 7, Apple also warns customers when they are using unauthorized cables or accessories with their devices. The company's Lightning connector, introduced with the iPhone 5, fourth generation iPad, and original iPad mini, utilizes several different chips to manage dynamic pin assignment and to recognize whether connectors came from authorized channels.
Apple's own chargers, as well as those that have been MFi certified, "undergo rigorous testing for safety and reliability," according to the company, and are designed to be safe and work properly with iOS devices.