Battery Fan

The battery fan runs based on internal temperature sensors of the HV battery. The fan is also variable speed and you probably cannot hear it when it is running low speeds. If the fan is running when the ambient temp is hot and the cabin is hot, this is normal. The battery is trying to protect itself.

If you run the AC in hot weather and keep the cabin comfortable then the battery temp should be comfortable. In hot weather the fan will run until the cabin temps cool down.

If the fan runs a lot even when the ambient temperatures are cool, you may want to take it to the dealer to make sure you are not having some internal issues with the HV battery.

 

Yes, the cabin air is used to cool the batteries. So, you really want to keep the cabin cool so the batteries stay cool.

 

I've found that the fan comes on if there's heavy draw or heavy.... push? to the battery. ie, when I'm not driving gently, or driving through the mountains in PA...

-Iain

 

Good point. Any heavy current draw, both charging and discharging, produces heat in the battery and will also cause the battery fan to run more often and at higher speeds.

 

HV battery fan has 6 speeds (including off). If you are hearing it, it is running pretty hard. Turn on the AC. If the interior temp is not comfortable, neither is the HV battery.