iPhone 6 Storage getting used up randomly and battery usage high and phone getting hot
My iPhone 6 64Gb has about 21Gb of storage used. I am randomly getting 'storage almost full' warnings associated with high battery drain and the iPhone getting warm. Then dropping back to normal space and battery use. This seems to be a cyclic thing.
When I go in to the storage settings under usage, it shows all of my storage has been used and 0Gb remaining. I have force closed all of my apps and restarted which sometimes results in the storage returning to normal with 21Gb used and 31Gb free.
I have carried out a 'reset all settings' with the problem reoccurring.
If I connect my phone to iTunes while it is going through one of it's cycles, the iPhone summary screen shows that I have a huge amount of 'Documents and Data' which increases as my free storage drops.
This 'cycle' seems to be getting more frequent and increasing my battery drain.
Does anyone have any other ideas? I am in the process of carrying out a full restore to see if this fixes the problem.
Thanks
Windows 7