TexasLeaf wrote:The 2018 Leaf doesn't have temperature bars, just a gauage with blue, normal and red ranges.
Actually it appears that I was wrong. The temperature gauge of the 2018 Leaf is broken up into the same twelve segments or "bars" as the temperature gauge of the older Leafs; two bars for the blue zone, eight bars for the normal zone and two bars for the red zone. Except there is no gap between the bars so the gauge looks linear instead of the true step gauge that it is.
I ran a little test on my way to and from work today, a 13 mile trip each way. On my way into work, I drove at 70 mph, I turn the heat pump on and rolled down the windows but on my way home I drove at 60 mph and I turn on the air conditioning as usual. On the morning drive it was about 77 degrees F outside but on the evening drive it was about 96 degrees F.
I started both trips with the battery temperature gauge at six bars. When I finished the morning trip the battery temperature gauge was still at six bars and the engine compartment was cool. When I finished the evening trip the battery temperature was at seven bars and I could feel quite a bit of heat rising from the motor compartment when I opened the hood.
I know the range between bars is so great that comparing bars is hardly a reliable test. But the motor compartment being cool at the end of my morning commute indicates to me that the heat pump removes a significant amount of heat from the engine compartment and has to be helping to cool the battery. But the thermostat only goes up the 90 degrees F, so if the ambient temperature is hotter than 90 degrees the heat pump won't come on and remove heat from the motor compartment and battery.
Whenever I have had trouble with high battery temperature and CHAdeMO charging speeds the battery temperature gauge was reading ten or eleven bars. I am fairly confident that ten bars causes the battery thermal management system to restrict CHAdeMO current flow. I am also fairly confident that if you start your CHAdeMO charge with the battery temperature at eight bars or less you should be able to fully charge without restricted current flow.
So the object of my tests will be to manage the vehicle operation to maintain the battery temperature at eight bars or less on very long trips with many CHAdeMO charging stops. I understand that CHAdeMO charging is probably going to raise the battery temperature up to ten bars. The vehicle operation is going to have to be able to not only maintain the battery temperature at eight bars but also bring down the battery temperature form nine or ten bars after charging.
I envision starting out a long trip in the morning driving normally at the speed limit. As the trip progress and the battery heats up, the heat pump would need to be turned and vehicle speed reduced as necessary to keep the battery temperature to eight bars. Once the ambient temperature rises above 90 degrees F, only vehicle speed would be effective in controlling battery temperature.
It's going to be a few weeks before I have enough free time to perform these test. By then I also hope have LeafSpy so I can have a more accurate way of telling what the battery temperature is. In the meantime any feedback would be welcome.