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Richard, Android Engineer
Category: Android Devices
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Experience:  Android Systems Specialist
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I get heavy battery drain after reboot with 128GB card

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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?

Thank you for your question, my name is ***** ***** I look forward to assisting you.
Please note, click on Reply to Expert to reply to me, a rating is only needed when we are finished.
The phone has a technical specification of acceptinng a maximum of 64GB "Expansion slot: microSD™ card, up to 64 GB (SDXC supported)" Seen here
It should not even be reading the 128 but I suspect that did not do an initial boot check on SD card size so the phone just keeps reading it, and when it gets past the 64GB this is when the issues occur. IT will likely be running out of memory for the FAT and this will lead onto a number of issues, likely internal processes crashing on the phone.
You see that when using the 64GB there is no problem. Your only solution and Sony should have picked this up, is to use only 64GB which fits into the specifications that the phone states.
If you would like any additional information or assistance, please do not hesitate to let me know.
And if you can take a second to rate my service, that would be greatly appreciated.
Thank you
Customer: replied 3 years ago.

Dear *****,

Thanks for your reply.

It's true that the phone is only rated to 64GB cards. I checked with Sony Support who confirmed that. I asked if 128GB cards would work and they said that they couldn't guarantee it, and the read/write speed performance might not be ideal. (I haven't noticed that problem.)

On the other hand, the card does work until you reboot. You can read and write all the files fine. And once the problem has occurred, removing the card and rebooting does not fix the problem. Only clearing the media index stabilizes the phone.

Additionally, web commentary suggests that the card will work in a Z1 Compact:

Further the Sony support forums suggest other people have the similar problems. Both with a 64GB card in the Z2 and with a 128GB card in the Z3 (both of which are compliant with Sony's specifications):

Reading the support in more detail, I wonder if there is a bug in the Android OS (or Sony's version of it) for media scanning large MP3 collections.

I am a bit reluctant to spend £300 for a Z3 Compact on a gamble that it is just because of the phone specifications. Do you have any evidence that 128GB cards fundamentally don't work in Z1 Compacts? Aren't the forum comments suggestive of an OS problem?



It is really easy to confirm this Martin.
Do a factory reset of the device, then use the card and see if the problem continues. It is going to be a bug dealing with 128GB as the OS implementation has not been written to handle this.
I have no "evidence" but logic points to this as the phones os is not designed to handle 128GB.
Customer: replied 3 years ago.

Dear *****,

As I said above I have already five (5) times done a re-flash of the phone's firmware (as well as four factory resets). This doesn't fix the underlying problem.

The only thing that puts the problem into remission is clearing the media cache (Settings/Apps/All/Media Storage, clear stored data). This stops the heavy battery drain until the phone has been rebooted. [And obviously a firmware re-flash or factory reset would clear the cache too.]

Whilst the media cache is in a good state, the phone works well with the 128GB card and all functionality is fine.

It looks to me like the media cache is getting corrupt after rebooting. I suspect this is caused by one of the following:

* Android OS bug for cache rescan - problem can be fixed by Google fixing the OS bug.

* Card is bad/corrupt in some way, and Android OS doesn't cope well - problem can be fixed by buying a new card (or making Android more robust)

* Card is ok, but a file on it is corrupt in some way, and Android OS doesn't cope well - problem can be fixed by fixing the bad file (or making Android more robust)

* Card is too big for the phone (your suggestion) - problem can be fixed by buying a Z3 Compact.

I am looking for a way to diagnose the problem between the four alternatives. Other people's experiences suggest it's not #4 (Z3 has the same problem). My own testing is against #3 (64GB card with same files is ok), and slightly against #1 (ditto) and #2 (card seems ok). So I don't have strong evidence in favour of any one of them.

Do you know of any way to get hold of the contents of the media cache? Can it be inspected to see what's in it, and whether the contents are bad/corrupt? Or any other way to choose between these options.

Thanks again for your help.



No it cannot sorry Martin.
But I believe your over complicating the solution.
It is designed to handle and work with max64GB. The OS has been designed for this and its internal memory set for.
Your using twice the max memory allowed.
If you wish I can opt out but another expert will tell you the same thing, that your using twice the amount of memory that can be used and hence the OS runs into these problems.
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