LeftieBiker wrote: First, you seem to have been trying to use "test" results from very mild weather to extrapolate to hot weather. Second, when the Leaf temp "gauge" is in the red it is definitely cause for worry. I don't know why you think otherwise, but please keep in mind that the Red zone of ANY temp gauge should be considered a definite warning. Manufacturers don't use red because they think it's pretty.
No, I am using the tests I conducted to extrapolate with different weather conditions simply because others have done essentially the same test in much hotter conditions in Arizona and come up with similar results. With the current LEAF batteries, elevated cold and hot environments are not as big of a factor as they were with pervious generations of the battery.
Now I do have expressed concerns with the HMI of the LEAF temperature gauge to those responsible for it, because there are lots of folks that come to the same conclusion that you have, based on their historical perceptions. Nissan's subtle approach using long and short blue and red marks to indicate operating range does not click with many of those that use preconceived notions and fail to RTFM. The Goldilocks area is between the short blue line and the short red line.
The other issue I've seen is that many people that come to your conclusion about what the gauge is describing is that they may not be familiar with a car that has automatic systems that protect the vehicle if there is a critical overheat (and underheat) situation by restricting the power available to the car until it is back within an acceptable operational temperature. Just about every BEV has a "turtle-lite" mode like the LEAFs that is designed to keep the vehicle's battery from being damaged. The car takes care of the situation that you are worried about so you don't have to.
As described in the owners manual the area between the short and long red mark is the warning area you are thinking of, and beyond the long red bar is where the automatic battery protection systems activate. The same goes for the short and long blue marks. In all the LEAFs I have driven over the years and all of the purposeful abuse I have laid on them, I have never had a situation where the temperature bar has gone beyond the first short red mark. Of course it does happen, and if one does get into that situation, the solution is to either drive slower, or stop for a while and let the battery cool a bit. I've found that the current battery can recover from being at the short red bar in 15-30 minutes by simply stopping or driving slower.
So again for the umpteenth time here is the section that describes that gauge. The key takeaway is that if the white bar on the gauge is between the short blue and short red mark, regardless where on the gauge it is, that is the normal operating temperature.