For dashcam recording, use a genuine U3/V30 microSD card up to 256 GB. U3 and V30 specify a minimum sustained write speed of 30 MB/s.
Prepare the card
Choose a card from a reputable supplier and check its speed class and capacity.
Save any files you need from the card.
Insert and format the card in the CHIGEE Display before first use.
Check that recording starts and that a saved clip plays back.
A worn or defective card can still produce write-speed warnings even if its label says U3/V30. See SD card requirements for models used only for firmware updates.
How much recording time will fit?
Recording time depends on the recording mode, resolution, frame rate, bitrate and available storage. A larger card holds more footage, but capacity alone does not give an exact duration.
To estimate your own setup, record a timed sample using your normal settings. For separate front and rear recordings, add both file sizes. Divide the available recording space by that combined sample size, then multiply by the sample duration. Use the same units for both sizes.
This is an estimate, not a guaranteed retention time. Save important clips before loop recording replaces them. See loop recording and locked videos for what happens when locked footage fills storage.