EOS R5 Scotch Tape Battery Overheating Trick. But…

In my last post, I gave my opinion that the EOS R5 overheating issues were NOT artificial because the overheating temperatures were fairly consistent. Well, I was wrong. YouTuber J. Marcus made a video showing how if you trick the camera to thinking the battery door was closed. Several others have made a similar video by now. Essentially you keep the battery door sensor down with a toothpick or piece of plastic to trick the camera in thinking the door is closed when it isn’t. Doing this allows access to the battery when the camera is on. You pop the battery before over it overheats, put the battery back in and get more recording time then you had before you popped the battery. This seems to prove that the camera is NOT simply taking temperatures from different components and then shutting down when those temperatures reach a threshold.

The scotch tape battery trick test seems to show that the camera is writing usage of the camera to NVRAM (Non Volatile Memory) and then determines if it is overheating from there. Other tests where camera owners put the camera in a freezer have been able to achieve longer record times too. So there is some combination of temperature and usage being used to determine when the camera is “overheating”.

Anyway, I wanted to try the battery door trick. I want to add the additional step of getting the EXIF Camera Temperature when I pop the battery, and then again when the camera overheats after I put the battery back in.

DISCLAIMER: I DO NOT RECOMMEND THIS. YOU MAY DAMAGE YOUR CAMERA IF YOU TRY IT.

I opened the batter door and stuck a clean Starbucks stopper in the battery door sensor slot and taped it there. I recorded 4k 120 until I got the overheat warning and an additional minute after that. It was about 13 minutes of recording. I popped the battery out before it shut down due to overheating. I waited 10 seconds and put the battery back in. I deleted the video I took to clear up space on the CFExpress card and took a picture for the EXIF camera temperature. Then I started recording 4k 120 again. It told me I had 4 mins and 23 seconds of record time. Remember I was about to shutdown due to overheating when I popped the battery. I probably had about 30 seconds of record time before I popped the battery. I let it record in 4k 120 again until it shutdown due to overheating. It took about 5 mins. I turned the camera back on and took another picture for the EXIF information.

Here is are the results:

When	Temperature
After Popping Battery	58 C
After Overheating After Popping Battery	67 C

Conclusion:

There is definitely some artificial overheating going on here. If it were just doing a straight temperature check it would have overheated when I put the battery back in or at least within the 30 seconds it had left when I popped the battery out. I was wrong about this in my previous post. However, if you look at the data you can see that whatever algorithm Canon is using it is very good at shutting down consistently when the EXIF camera temperature is between 50 C and 60 C. The only time I have seen it outside that range is in this test where we cheated the algorithm. Also, please notice that the second time after I cheated the algorithm the EXIF camera temperature was much higher than it has been before during any of my overheat tests at 67 C. As I stated in my previous post this is outside the range of optimal performance for a CMOS sensor and likely a really bad idea to perform this trick on a regular basis. IT may damage your sensor or other components. PLEASE UNDERSTAND THE RISKS IF YOU TRY IT!

Canon is overheating logic does not seem to be done in a simple easy to understand way. However, the algorithm does appear to be consistent, by overheating within a certain temperature range. Their algorithm may be confusing, but I suspect it is in place for a positive reason and not a nefarious one as many reviewers want to think. It is mostly likely done to protect components and NOT to cripple the camera’s abilities.

However, the camera does cool down fairly quickly, including in this test. The cool down temps do NOT seem to correlate with the amount of recording time allowed by the camera during the cool down. I have re-reviewed the data from the first post, and I think Canon might have quite a bit more room here than I previously thought. This will be the main topic of my next post.

Please leave a comment below and let me know what you think.