JRP3 wrote:There is a fan inside
No, you didn't dream it up. Nissan said there was a fan once-upon-a-time, but it never materialized in the production car.JRP3 wrote:For some reason I thought there was an internal fan to even out heat distribution. Guess I dreamt that up in my head.
It's difficult to radiate heat to the air since air does not absorb infrared light effectively. Any radiation from the LEAF battery would be to other surfaces that surround it such as the floorboards or the plastic sheet below it, and, yes, that is pretty limited.JRP3 wrote:Theoretically the "cooling" system is passive radiation from the pack to the outside air, obviously not effective in this case.
Most of the cooling of the LEAF battery when driving is through conduction to the unibody and conduction from both the battery and the unibody to the air. When the car is moving heat gets carried away by a form of convection due to the car moving to cooler air all the time. However, when the car is at rest, the warm air around the battery is somewhat trapped so the heat takes a long time to dissipate.
Since the LEAF battery is a net dissipater of heat, the lower temperature limit is the ambient air temperature. In reality, its average temperature will be above the ambient level. This is good when it is cold outside and bad when it is hot.