
To activate the heated rearview mirror in BYD, press the rearview mirror heating button on the air conditioning control panel. The exterior rearview mirrors will then heat up and automatically turn off after approximately 12 minutes. Working Principle of Heated Rearview Mirror: The electric heating element behind the rearview mirror glass rapidly heats up to a fixed temperature within a few minutes, typically between 35-60 degrees Celsius. Warm air will emerge from both left and right rearview mirrors, while water droplets on the mirror surface will gradually evaporate and shrink due to the rising temperature. The fog will also slowly dissipate, effectively defogging and defrosting the mirror. However, during heavy rainfall, its effectiveness may decrease and become less noticeable. Precautions for Using Heated Rearview Mirror: The heated rearview mirror consumes a significant amount of electricity, so ensure the vehicle is in the started state when using this function. Avoid using it when the engine is cold. Additionally, the heated rearview mirror function should not be overused. Each usage should not exceed 30 minutes to prevent affecting the mirror's lifespan and clarity. If convenient, the driver can simply wipe the mirror with a dry cloth instead of using the heating function.

Operating the rearview mirror heating in a BYD is actually quite straightforward. I figured it out last time when driving an older Qin model. Look near the driver's side of the center console, around the air conditioning panel—there's a button with a rectangular frame and wavy lines, right next to the defroster symbol. Just press it after starting the car; the indicator light will show it's heating. It's especially useful on rainy or foggy days—water droplets on the mirror start evaporating in about two minutes. Note that this function is linked with the rear window defroster—pressing one activates the other. But don’t rely on it too much; effectiveness decreases in heavy rain, so slowing down is the safest option.

I find this feature particularly useful when driving on highways in rainy weather. The button locations vary across different BYD models: for the Song series, you can typically find the square heating icon with an arrow among the physical buttons in the air conditioning control area; in newer models like the Tang and Seal, it might be integrated into the air conditioning menu on the central touchscreen—just tap the air conditioning interface and look for the rearview mirror symbol. It's especially practical during winter frost, but note that the heating speed can be slow right after starting the vehicle. A handy tip: if the rear defogger is on but the mirrors aren't responding, it could be a blown fuse, though this is quite rare in BYD vehicles.

Once when driving a colleague's BYD Han during a heavy rain, I figured out a useful trick: After starting the vehicle, directly locate the physical button with an upward wavy line and square icon, usually near the gear shift. Press it, and when the indicator light turns on, the heating begins. The principle is actually resistance wire heating, similar to how a smartphone screen heats up. However, it automatically turns off after a maximum of 15 minutes to prevent overheating, so you'll need to manually turn it on again when the mirror is half-dry. This feature is super useful during the humid 'Hui Nan Tian' season in southern China.


