If the usual iphone charging time is normal, suddenly the charging time slows down, then it is likely that the charging process need to use the location of some problems, may wish to try these several calls to improve.
Clean up the charging socket
As usual we are used to put the cell phone in the trouser pocket, located at the bottom of the phone charging interface easily into the ash, interface and power cord plug easy to contact bad. So the phone can not be charged, the first time to check the phone at the bottom of the interface is a foreign body blocking.
Replace data cable
If the iphone's charging speed is still abnormal after cleaning up the iphone's charging socket, it is likely to be a data-line problem with the charge. You can use someone else's iphone data cable to try to charge. If the line after the charge speed is normal, it means that the line out of the problem, speed to buy a new data line bar.
Restart the iphone
The iphone is slow to charge, does not respond to charges, and can sometimes be a systemic cause, causing the phone to not recharge. Restart can solve 70% of mobile phone problems, we can remember the "truth", the phone out of the question may wish to restart to try.
Transfer charge environment
In the summer, the temperature rises abruptly, and the hot weather also affects the iphone's charging speed. Because of the physical properties of the battery, it is particularly sensitive to temperature, too high can cause problems, too low will lead to not charge electricity. If you are in a place where the temperature is extreme, please keep your phone at a normal temperature and recharge it.
If none of the above solutions solve the problem, it is likely that the hardware of the iphone has gone wrong. This is the most unfortunate situation, need to go to Apple after the sale or professional maintenance agencies to overhaul.