topic Re: EOS R5 Mark II overheating with firmware 1.0.2 in EOS DSLR & Mirrorless Cameras

EOS R5 Mark II overheating with firmware 1.0.2

brunoh — Tue, 15 Jul 2025 08:32:59 GMT

I am working in a tropical South-East Asian climate and shoot only stills. I take early morning shots with long exposures and use M, B and AV. After about 90 mins of work my R5 Mark II is overheating. It did NOT upgrade 1.0.3. I did not have this issue with the R5. The memory card is a SanDisk Extreme Pro CFexpress 256 GB. Had the card for about 5 years. Any advise about the reason of this overheating and solution proposals? Thanks

Re: EOS R5 Mark II overheating with firmware 1.0.2

moshe360 — Tue, 15 Jul 2025 18:19:04 GMT

I would recommend to try using the Canon CF-R20EP Battery Grip with Cooling Fan. It doubles your battery life and keeps your camera cool in hot environment. Then, make sure you use it in a shadow and not in a direct sun ( can use some small shade attached to the tripod for that), and finally try using a non Sandisk memory. For some reason their memory cards many times have weird incompatibility or overheating issues. I'm using 2TB Lexar card and it gets hot but never overheating with fan on medium speed (i shoot Raw Lite 8K video).

Re: EOS R5 Mark II overheating with firmware 1.0.2

shadowsports — Tue, 15 Jul 2025 18:31:08 GMT

Greetings,

I'd like to clarify a few things.

The AF issues reported about FW v1.0.3 appears to be tied to certain subset of power management features. Many users who didn't make changes or use defaults are not having issues. If you are using default power management settings, I wouldn't worry about upgrading to v1.0.3.

Sandisk memory cards. The affected cards were SD cards v60's, 64,128 and 256GB. All v90 cards, various capacities are fine. The v60's that have a blue dot on the back have upgraded firmware and are now said to be compatible by SanDisk. My recommendation is sticking with v90's.

Overheating issues. The R5 Mark II also has a settings called auto power off temperature. Changing this to high will allow extended run times. Using a tripod is recommended as your hands can actually insulate the body from dissipating heat efficiently.

Canon : Product Manual : EOS R5 Mark II : Auto Power Off Temperature https://share.google/1vaV3bzzvJ2tbGFtC

A battery grip as @moshe360 suggested might definitely help if you're shooting in high temps.

Re: EOS R5 Mark II overheating with firmware 1.0.2

brunoh — Wed, 16 Jul 2025 07:04:22 GMT

Hi Rick,

Thank you very much for your assistance. Very much appreciated.

Bruno, Cam Ranh, Vietnam

Re: EOS R5 Mark II overheating with firmware 1.0.2

brunoh — Wed, 16 Jul 2025 07:06:44 GMT

Thanks moshe360, your assistance is very much appreciated