Causes
- The card cannot sustain 4K 60fps writes the A810 writes 3840x2160 H.265 footage at roughly 40 to 60 Mbps, plus a second channel when an RC11 or RC12 rear camera is connected. U1 and V10 cards, and older UHS-I cards with slow random write performance, drop below that sustained rate, the write buffer fills, and the camera reports a card error and stops loop recording mid-trip.
- The card was formatted on a computer instead of in the camera Windows and macOS produce exFAT or a FAT32 layout the A810's loop manager does not expect. An in-camera format creates the Normal, Emergency, and Parking folders the firmware writes into, and a card prepared on a PC can fail the card check at boot with a format prompt.
- The card is not fully latched in the slot the microSD slot needs a firm push until it clicks, and the card sits almost flush with the body. A card left a fraction short makes intermittent contact, which tends to show up as a card error after the first bump rather than immediately.
- The card has run out of endurance loop recording rewrites the card continuously and parking mode multiplies the write volume. TLC cards switch to read-only or start returning write failures after 12 to 24 months of continuous use, and the A810 can only report that as a generic card error, not as a worn out card.
- The card is outside the supported spec or is counterfeit 70mai rates the A810 for 32GB to 256GB cards. Anything above 256GB, and any counterfeit card that advertises more capacity than its NAND holds, fails once the real memory ends, usually during the first long recording or the first loop overwrite.
How to Fix
- Format in the camera, not on a computer. With the card inserted and the camera powered, press the menu button, open Settings, choose Format, and confirm. Wait for the completion message before leaving the menu, then record a two minute test clip and check that it plays back on the device.
- Reseat the card. Power the camera off, push the microSD in until it clicks, release it, then push it back in once more. Pulling and reinserting a card scrapes light oxidation off the contacts and clears the most common intermittent card error.
- Match the card to the workload. Use a 32GB to 256GB UHS-I U3 or V30 high endurance card, such as 70mai's own High Endurance line, SanDisk High Endurance or Max Endurance, or Samsung PRO Endurance. Stay away from U1 and V10 cards sold as 4K ready, and do not exceed the 256GB ceiling.
- Rebuild a suspect card from scratch. Put the card in a reader, run SD Card Formatter with the Full (Overwrite) option, then format it again in the A810. If the overwrite pass stops with a write error, the card is failing and no amount of reformatting will recover it.
- Test real capacity and speed. Run h2testw or f3 on the card from a computer and write until it is full. A counterfeit card fails exactly where its real NAND ends, while a worn card returns errors before the end. Both mean replace the card.
- Drop the recording load while you wait for a new card. In Settings, change the front recording resolution from 4K 60fps to 4K 30fps or to 1440p. Lowering the bitrate lets a marginal card keep up for daily driving, but treat it as a stopgap because 60fps is the reason to own this camera.
- Update the firmware. Connect the phone to the camera's Wi-Fi, open the 70mai app, go to device settings and firmware update, and install anything pending with the camera powered from the car. Card handling and file system fixes have shipped in firmware updates, so re-check the card error afterwards.
- Replace the card if the error returns on a good one. A correctly rated card that was freshly formatted in the camera and still throws a card error within a few hours of driving is finished. Continuous rewriting is the normal workload here, so plan on a new high endurance card every year or two of heavy parking mode use.
