TonyWilliams wrote:Awesome. Why isn't 281 valued at 100% ?
As to the total usable kW, it would be handy. My trip today averaged 52mph, and 4.4miles/kWh.
If I can go 96 miles at 50mph, and 4.4kWh leaves us with 21.8 usable battery. I'm not even sure if this usable is static. For instance, if I'm really working the battery hard, is it less efficient (meaning a higher percentage of energy is lost as heat?).
The 81 mile range at 60mph is 3.7 miles/kW/h at 21.8 usable. I think I'm a couple miles short on absolute range, however.
This will all get more difficult as the batteries age.
Yes, I read up on your recent trip, excellent report. Congrats on making it back and on your meticulous planning! I punched in the data you provided, including charge times, into my calculator. It looks like the kWh estimates hold up; the predicted range was within 5 miles of your actual. I used 85% efficiency factor for charging and battery capacity numbers predicted by the model.
What exactly is the model then? It's essentially an approximate SOC point to kWh mapping. The mapping itself is speculative, but it seems to be be in alignment with other observations voiced on this forum and with the data gleaned from the few and far between comments from Nissan. I also found some very helpful information on the Tesla owners forum, and I believe that the Leaf is much closer to the Roadster in terms of charging protocols and battery care than we think or Nissan has admitted.
But back to the model. SOC 281 is not valued at 100%, because it very likely does not represent 100% pack capacity. It's the full available charge, which is less than 24kWh for the sake of battery longevity. The mapping I'm proposing assumes 320 SOC points representing 24kWh. Each point would be 0.075kWh or 75Wh. There is a silent reserve on both ends. It's likely 20 points below zero, that's what's left in the pack when the Leaf stops dead after turtle. There are another 19 points above 281 to make it full 320 SOC points. I took this metric and added pack SOC % and kWh estimates to your chart.
I've been using it during my driving to see if it holds up and so far it's been pretty good. Not 100% accurate, but good enough. I would be interested in measuring energy economy at various speeds. I drove 10 miles on a flat stretch of freeway this morning at a constant speed. I think that this could be quite useful. When you have a kWh estimate and know the distance you want to travel, you could select the most appropriate speed based on MPK measurements. You could also adjust your driving to make sure that the average MPK is within the necessary limits to get you to your destination.