I get heavy battery drain, phone heating and erratic behaviour after rebooting when my 128GB card is inserted.
I have a Sony Xperia Z1 compact with Android 4.4.4, and Firmware 14.4.A.0.157.
I have a 128GB MicroSD card with around 15,000 MP3 (and some MP4) files. The card is SanDisk, formatted as exFAT. The files contain some long file names and ASCII characters above 128, but no unicode.
If the card is inserted, the phone appears fine and the Android media cache is generated.
But if the phone is rebooted (and a new media scan is performed), then things start to go wrong. Battery drain increases (driven by Media and Google+ typically) from 1%/hour to 20%/hour, the phone heats up as the battery drains and apps become slow or unresponsive.
The phone can be stabilised by removing the SD card and then going to Settings/Apps/All/Media Storage, clearing the stored data and forcing a stop. Then reboot the phone. Please note that just removing the card does not stop the problem - the phone continues to churn until the Media Storage data is cleared.
But re-inserting the 128GB card and rebooting will trigger the problem again.
I have spoken to Sony a couple of times, but they only recommend re-flashing the firmware. I have now done this five times since December and it does not fix the problem.
Interestingly, I also have a 64GB SanDisk card, also exFAT. When it is populated with similar data, it works fine with the phone. But Windows Explorer/Properties/Tools/Error-checking says that both cards are (equally) good.
The 128GB card appears good in terms of files and data.
My best guess is that repeated media scans of the 128GB card are causing the Android Media Cache to become corrupt. But I don't know how to investigate or prove this, or discover which file(s) causes the problem. Or why one card causes the problem and the other card does not.
How do I fix the situation so I can have a 128GB card in my phone?