I love the concept of this graph, just run some real numbers and I think you will see the numbers across the board are optimistic for 2 reasons.
1) First is aerodynamics and drag. I agree with everyone above, you can not maintain 85 mph for even an hour as drag is too high, and you will be hard pressed to ride at even 75 mph for an hour, its doable with a tailwind but not normally.
2) But most important is a 1C 1 hour charge time is great, but effectively its really almost 1.5 hours. To effectively measure charge time, you need to measure the total kWh added which say is 11.4 kWh on a 2017 13.0 SR at a charge stop from 0% to 100%.
You charge from 0-85% in 53 minutes at almost 12 kW (2 J plugs), but your charger tapers as voltage reaches 116 and it takes you 27 minutes until you are charging at less than 1000 watts and are full. So that is 1 hour 20 minutes.
But wait, there is more. You added 11.4 kWh in 1 hour 20 minutes, but the charging stop was 2 miles off the highway, and from the second you got off the exit, to the moment you got back on after charging is the time you need to use. Say it was 5 minutes on both ends. so your total charge time to add 11.4 kWh is actually 1 hour 30 min! or .75C not 1C
But wait, there is more. You have to account for time it would take to replenish the 4 miles of total energy (at slower speeds) to get to the charge station and back from the highway as you may have left the highway at 3% and arrived back on the exit ramp at 97%
So subtract that from your energy added and you will see you're now like 0.75-0.7C
But wait, there is more. You can't maintain 85 mph all the way down to 3% battery. You can't even maintain 75 mph. And unless you have a tailwind and are going down an incline, chances are it will be even slower. So lets say you exit the highway between 10% and 20% SOC. you are now charging less total at 1C (20% to 85%) but you still have to wait the same time for the taper charge, and it still takes you the same time to get on and off the highway and plug in. And it still takes energy to do that.
Guess what? You're 1C charge rate effectively becomes much closer to a 0.5C charge rate than it does 1C
And to calculate the best possible range, you want to match your ride rate to your charge rate. If it takes 2 total hours to charge, you want to discharge in 2 total hours. To ride for 2 total hours on the highway, you need to be around 55 mph or slower.
If you don't believe me, get some Diginow superchargers, and plan a single point about 50 miles away with dual J plugs. Leave your house and top off at the closest dual J plugs to your house. The second you are full and take off you start a timer. Stop at the dual J plug location about 50 miles away and charge to full or as much or little as you want. Turn around and go back to the first location and top off all the way to 100%. I think you will find even with 1C charging, the slower you go down to perhaps 55 or 60 mph the total less time it takes. As at 55 mph you perhaps don't even have to stop at the 2nd station, you can just bypass it and turn around and be able to make it back. Think about how much time that saves, right?
This is the other factor. You might have to stop early to charge because there are Dual J plugs 35 miles away, but not again for 80 miles. In 60 miles there is a single j plug only. You want to try to skip that Since you don't want to try to ride 115 miles at highway speed, you stop at 35 miles to top off, but now you spent waiting for the full 100% taper charge, you spent the time getting on and off the highway, and the energy to get there just to add say 50% to your battery, and in this case your effective charge rate is well below 0.5C even though you charge at a 1C charge rate. Does that makes sense?
Or you skip the dual J plugs in 35 miles and go to the single J plug but now your charge rate actually is 0.5C, you see? There's a lot of strategy that is hard for a simple computer program to account for all factors.
You want the numbers where it makes sense to ride 85 mph or faster? Get a Vetter fairing. My effective speed to travel for the least total time on a trip was over 100 mph, so the actual speed limit or about 10 mph over is what limited my the time of my trips. This is the slightly modified 2012 Zero I went over 1000 miles on in less than 24 hours on in 2014. And in 2015 went over 300 miles at Interstate speed on a single charge. So you might say I have a little experience with estimating times and range. With this little drag, the penalty for going faster is minimal, and the ability to choose to only stop where there are 4, 8 or 12 J plug or more at one location becomes easier to choose while skipping over the charge stations that are not multiple.
Add some more variables and your graph estimation will begin to get more accurate. I'm excited to see it! I hope this helps explain some things you might not have thought about.
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Topic: a bit of math (1C charging) (Read 1450 times)