Can a micro SDHC card overheat?

[Quattro Pete]

The card is a SanDisk Ultra Class 10 32 GB.

When I used it in my Android phone, sometimes the contents on it would become inaccessible. I am still not sure what the cause is. I tried reformatting the card and scanning it in a PC - it turned up no problems.

I also tried to see how it performs in the PC (via a USB card reader). When saving large files to it, I noted that the card would heat up a lot and the transfer speeds would slow down to a crawl. Can micro SDHC cards overheat? Is mine defective?

I started perusing Amazon reviews for this card, and while the majority of the reviews are positive, there is a sizable number of negative reviews stating the card was defective.

 

[gomes512]

I'd exchange it if you can. Had a UHC-1 class card do the exact same thing in my laptop. Large files sent from Premiere would heat it up noticeably and the transfer speed would come to a crawl. Had SanDisk send me a new one, 600Gb's so far without issue. Hope it stays that way.

Thinking maybe something with the controller was defective.

 

[Corvette Owner]

Yes, they can overheat. Check out this:

http://forums.fedoraforum.org/showthread.php?t=281994

 

[Nick R]

Only Micro SDHC card I've never had trouble with is the G Skill one I have now. Was cheap and has lasted longer than any of the others I've had.

 

[dparm]

Their operating ranges are massive. It's not overheating -- probably bad memory cells. Exchange it.

 

[SwampSurvivor]

I've always had hit or miss luck with SD/SDHC cards and the mini/micro variants.

 

[bubbajoe_2112]

Interesting question, one I haven't run across before.

Here is temp specs for Sandisk:
Operating temperature:

From the desert to the glaciers, guaranteed -13ºF to 185ºF (-25ºC to 85 ºC)

That's no guarantee that it's not overheating though. Interested to hear more on this one...

 

[PandaBear]

The memory cells are designed to last worst case non operating condition of 85C. Beyond that the charges could leak and you can get data corruption. If it is not defective it should not heat up to something that can corrupt the data with non stop write/read, otherwise the firmware (also stored in the flash memory) would be corrupted and you will not be able to boot it the next time you power up. They test those condition in the lab in design and manufacturing.

From my experience back when I work there (left 3 years ago), the most likely scenario is a bad card or the host (Android phone) has a certain write / partition format that hit the worst performance scenario. When that happens, the controller is busy doing garbage collection / wear leveling to free up space for your new data.

This happens more often on the lower end higher capacity cards that uses 3LC memory (3 bit per cell) because they are cheaper and slower, less likely to happen on the mid/higher end Ultra / Extreme cards that use MLC (2 bit per cell) and SLC memory because they are a lot faster.

Since yours is an Ultra, I'd warranty replace / exchange it and see if it works better. It shouldn't overheat unless there's a short somewhere.