PHOTOGRAPHED 6 APRIL 2025

It should be mentioned that the batteries are/were original Canon product and I have included a detailed discussion of the issue which may be of interest I you ever consider buying a used Canon 5D MkIII.

On 6 April 2025, I photographed Bolton Street using a Canon 5D Mark III. This camera, which I acquired a few years ago, has recently presented some intriguing technical challenges. My local camera dealer, aware of my extensive collection of Canon lenses (despite my shift to Sony mirrorless systems), offered me an unused 5D Mark III at a very favourable price. The camera had been won in a competition and remained unused for several years. I agreed to purchase it, provided he could supply a GPS attachment.

Currently, I am in the process of evaluating my photographic equipment, deciding which cameras to retain. I opted to use the Canon 5D Mark III for a week. However, upon powering it on, I encountered a ‘battery communication error’. Subsequent attempts with different batteries yielded the same error, and the display panel went blank, rendering the camera unresponsive.

After several hours of troubleshooting, I discovered that removing the SD card allowed the camera to restart. Inserting an old CompactFlash (CF) card enabled normal operation. Reinserting the original SD card caused the camera to crash. Replacing it with a new SD card resolved the issue.

This problem prompted me to investigate the Canon 5D Mark III’s operational characteristics, particularly concerning memory card compatibility and reported issues.

Canon 5D Mark III: General Operational Considerations

The Canon 5D Mark III, although a robust professional DSLR, has documented limitations. Some users report less flexibility in RAW file shadow recovery and inferior high ISO performance compared to the Canon 6D. The autofocus system, while adequate, exhibits weaker low-light sensitivity at its centre point than the 6D. This indicates trade-offs in specific photographic scenarios.

The 61-point autofocus system, while offering advanced tracking, requires considerable expertise to master, potentially leading to challenges in capturing fast-moving subjects. The complexity of this system suggests sensitivity to operational conditions and external factors, such as memory card insertion.

Additionally, reports of image sharpness issues, often attributed to lens calibration or wide-aperture lens characteristics, highlight potential operational challenges.

One particularly relevant account describes erratic camera behaviour following a low battery state, including spontaneous photo capture and unresponsive controls. Prolonged removal of the battery, lens, and memory card, to discharge an internal ‘keep alive’ capacitor, resolved the issue. This suggests the camera’s electronic systems are sensitive to power fluctuations, potentially linking my battery communication error to a past low battery or unexpected power-down scenario affecting peripheral communication.

SD Card Compatibility and Limitations

The Canon 5D Mark III features dual memory card slots for CF and SD cards. However, the camera’s SD card implementation has limitations. It is not recommended for high-speed burst shooting, as speeds are capped at approximately 20MB/s, despite supporting UHS-I SD cards. When both CF and SD cards are inserted, write speed defaults to the slower card, hindering CF card performance.

The camera does not support UHS-II SD cards, limiting high-speed card potential and potentially contributing to communication issues. Some photographers advise using the SD card slot sparingly, primarily for wireless transfers via Eye-Fi cards, and relying on CF cards for image capture.

Reports of the camera not stopping writing to both SDXC and CF cards, while different from my issue, indicate potential instability in memory card handling. Recommendations include formatting cards within the camera and using faster CF cards.

Simultaneous use of both card slots can reduce the camera’s buffer size, suggesting shared system resources and potential performance degradation or communication errors.

Firmware Updates and Memory Card/Battery Issues

Firmware updates often address bugs and improve performance. The latest firmware, version 1.3.6, primarily corrects PTP communication and update process vulnerabilities, not directly addressing SD card or battery communication issues.

However, earlier firmware, such as version 1.2.1, addressed memory card-related problems, including LCD monitor freezes during Live View and issues with Eye-Fi cards, demonstrating Canon’s awareness of memory card compatibility.

User Experiences with Similar Issues

User forums reveal reports of physically damaged SD card slots and instances where the camera powers on without an SD card but shuts down upon insertion. This mirrors my issue, suggesting a link between SD card insertion and power system errors. Recommendations include reformatting SD cards (FAT32 for cards 32GB or smaller, exFAT for larger cards) and trying new cards.

Other users report ‘Error 2 – card cannot be accessed’ and complete SD slot failures, further indicating potential SD card interface issues.

Interplay Between SD Card and Battery Communication Errors

While battery communication errors can occur independently, my issue appears triggered by SD card insertion. It is possible my ‘battery communication error’ is a power-related issue stemming from SD card communication difficulties. The camera might draw excessive power or experience instability when accessing the SD card, resulting in a battery monitoring error.

Cleaning battery contact points is a general troubleshooting step. Canon’s error code documentation does not explicitly mention SD card-triggered battery communication errors, suggesting it may be uncommon or misreported.

The fact that memory card issues can cause complete power-offs indicates a deep integration between memory card interface and power management, supporting the possibility of a link between these issues.

SD Card Age, Speed Class, and Brand Impact

The Canon 5D Mark III is compatible with SD, SDHC, and SDXC cards, with a suggested maximum capacity of 128GB, although larger cards are often supported. The camera operates UHS-I cards at Class 10 speeds and does not support UHS-II cards.”

The post I PHOTOGRAPHED BOLTON STREET USING A CANON 5D MKIII AND I HAD A CANNOT COMMUNICATE WITH BATTERY ERROR appeared first on URBAN CARTOGRAPHER 2025.