Range Chart

[johnr]

I modified your chart slightly to improve the readability. To each their own, of course, but it helped me visualize it better.

 

[evnow]

Here's my latest revision, #5, to the range chart. Like always, I appreciate critiques to make it better. The biggest change is that about 12.5 mph is the best range speed.

I'd change 32 & 43 mph to 30 & 40 mph. None of our numbers are "accurate" anyway - so rounding the numbers makes it easier to visualize (and remember) and I think conveys the right level granularity.

 

[surfingslovak]

I'd second the request to revisit the speeds presented in the table. Perhaps it would be possible to add 65 and 75 mph down the road. I'd be willing to help in whatever way I can.

On a related note, I've started using a new method to predict my remaining range. There is at least one other forum member using the same approach, and it seems to work quite well. So without further ado:

- reset your dash energy economy gauge (MPK) after each charge
- wait for the MPK number to settle (takes usually a 3 or 4 miles)
- multiply the MPK number by 1.5kWh to receive range estimate per bar
- multiply range per bar by the number of visible bars + 2 (reserve)

The range prediction is usually withing 2-3 miles of the actual. This method facilitates more dynamic driving, it's no longer necessary to maintain constant speed just to have confidence in the range estimate.

 

[mdh]

I'd second the request to revisit the speeds presented in the table. Perhaps it would be possible to add 65 and 75 mph down the road. I'd be willing to help in whatever way I can.

On a related note, I've started using a new method to predict my remaining range. There is at least one other forum member using the same approach, and it seems to work quite well. So without further ado:

- reset your dash energy economy gauge (MPK) after each charge
- wait for the MPK number to settle (takes usually a 3 or 4 miles)
- multiply the MPK number by 1.5kWh to receive range estimate per bar
- multiply range per bar by the number of visible bars + 2 (reserve)

The range prediction is usually withing 2-3 miles of the actual. This method facilitates more dynamic driving, it's no longer necessary to maintain constant speed just to have confidence in the range estimate.

great method SS, you've really helped me learn so much about this car.

 

[surfingslovak]

great method SS, you've really helped me learn so much about this car.

Thank you for helping me to refine it! Happy to share, it's great to be part of this community.

 

[evnow]

On a related note, I've started using a new method to predict my remaining range.

Here is another

http://www.mynissanleaf.com/viewtopic.php?f=44&t=5268

 

[surfingslovak]

Here is another

Nice, I saw your pics in the other thread! I have a feeling that this particular method will be the one to beat ;-)
Just out of curiosity, would it possible to read the MPK number from the CAN bus?

 

[planet4ever]

I don't like it! In fact I hate it! You are upsetting me no end.

Most of my driving is local, at speeds around 25-35 mph. Your table says I should be getting 6-7 m/kWh, but I'm not. In fact I rarely go above 3.5 m/kWh unless I get on the freeway, then I can get up around 4.3 at 60 mph.

Now, I am not doubting you when you say you can get 8 m/kWh driving around a circle at 10 mph, but that is really only a laboratory experiment. In the real world if you are driving at those speeds it's because you are in a traffic jam, or heavy city traffic, or on residential streets. In all of those situations you have stops. Lots of stops; stops for traffic, and unsynchronized signals, and stop signs, and balls bouncing out between parked cars.

Even you, LEAFfan, with your incredible 9+ m/kWh, can you get more than half that at any speed -- pick your favorite -- if you have to stop six or more times per mile?

You probably thought I was joking with my opening statement here, but I wasn't, not really. That chart lies when it comes to real world conditions. Please, for my sanity, put a big asterisk on there stating that the numbers apply only for constant speeds, no slowing or stopping, and that frequent stops can easily cut the figures in half.

Ray

 

[surfingslovak]

Most of my driving is local, at speeds around 25-35 mph. Your table says I should be getting 6-7 m/kWh, but I'm not. In fact I rarely go above 3.5 m/kWh unless I get on the freeway, then I can get up around 4.3 at 60 mph.

Ray, are you using AC most of the time? If so, what temp is it set to? Any hills in your area? I always had the sense that my energy economy was lower then what other owners reported, but that changed when I started measuring it at constant speed with no auxiliaries.

 

[thankyouOB]

how does this data figure in:
I go 50 miles a day, each day, to commute.
it takes 8 bars at 80% charge.
I use the AC for most of the trip and also use ECO for most of the trip.

that would be 6.25 per bar or a range of 75 miles.

Yet my average m/kwh is 4.4.

4.4 times 20 usable kwh in the car = 88 miles.
is my maximum range with this driving style and road mix 75 or 88?

any help from the SOC gurus?

 

[TomT]

I agree. When I drive at those speeds it is almost always in stop and go traffic and my efficiency takes a huge dive (even with AC off). Even with an intent to do so, it is hard to drive a constant 10 mph with any form of consistency for an extended period. The range shown at 10 mph has little bearing to the real world and is misleading.

Now, I am not doubting you when you say you can get 8 m/kWh driving around a circle at 10 mph, but that is really only a laboratory experiment. In the real world if you are driving at those speeds it's because you are in a traffic jam, or heavy city traffic, or on residential streets. In all of those situations you have stops. Lots of stops; stops for traffic, and unsynchronized signals, and stop signs, and balls bouncing out between parked cars.

 

[TomT]

So last night I did an experiment. I charged to 100 percent, reset my average M/KwH meters, and drove the car to battery exhaustion (it's good being near the top of a hill and being able to coast back in to my garage). I ended with an average of 3.8 M/Khw (on both meters) and I drove 89.3 miles. Doing the math, that would seem to indicate I used 23.5 Kw from the pack...

Edit: I used 26.71 KwH recharging.

 

[surfingslovak]

Yet my average m/kwh is 4.4.

4.4 times 20 usable kwh in the car = 88 miles.
is my maximum range with this driving style and road mix 75 or 88?

any help from the SOC gurus?

Great data, OB. If you are counting bars, here is what that would yield:

4.4 mpk x 1.5 kWh = 6.2 miles per bar
( 12 + 2 ) x 6.2 m = 92 miles on 100% charge
( 10 + 2 ) x 6.2 m = 74 miles on 80% charge

And if you had the SOC meter:

(281 - 4) SOC x 0.075kWh/SOC x 4.4 mpk = 91 miles on 100% charge
(236 - 4) SOC x 0.075kWh/SOC x 4.4 mpk = 76 miles on 80% charge

In my experience, this method is within 2-3 miles of the actual and if you discount the low granularity of the bars, the error is within 5%.

 

[surfingslovak]

Doing the math, that would seem to indicate I used 23.5 Kw from the pack...

Edit: I used 26.71 KwH recharging.

Indeed, thank you for posting that! I have unfortunately no explanation for these numbers. At least the charger efficiency is withing parameters. It appears to be 88%, I've been assuming 85% in my recent calculations.

 

[TonyWilliams]

I'd change 32 & 43 mph to 30 & 40 mph. None of our numbers are "accurate" anyway - so rounding the numbers makes it easier to visualize (and remember) and I think conveys the right level granularity.

Agreed.

 

[TonyWilliams]

The range prediction is usually withing 2-3 miles of the actual. This method facilitates more dynamic driving, it's no longer necessary to maintain constant speed just to have confidence in the range estimate.

You don't need to maintain a speed. 60 mph relates to 3.9miles/kWh, so if I drive around town at zero to some speed faster than zero, in stop and go, and end up with 3.9miles/kWh, I will have the SAME 81 mile range as going 60mph at a steady speed.

1.5kWh per fuel bar is fine, too, and merely reflects that same data of 21 kWh of usable battery power over 14 fuel bars.... which still makes 60 mph go 3.9 miles/kWh, which in turn will go 81 miles at 60 mph steady, or 81 miles range at ANY speed that equals an average of 3.9miles/kWh.

 

[TonyWilliams]

Ya, that's what I want. I'd add the "miles/kWh" with the speeds for those times when you're not cruising around at a steady speed. That gives us exactly the electronic version of this chart.



http://www.mynissanleaf.com/viewtopic.php?f=44&t=5268

[/quote]

 

[TonyWilliams]

I don't like it! In fact I hate it! You are upsetting me no end.......

Most of my driving is local, at speeds around 25-35 mph. Your table says I should be getting 6-7 m/kWh, but I'm not. In fact I rarely go above 3.5 m/kWh unless I get on the freeway, then I can get up around 4.3 at 60 mph.

Ray, I'd suggest a DEEP breath and to look at the data presented a bit differently. My table DOES NOT SAY that your around-town driving is the same at driving a steady pace. Unfortunately, there are too many variables to accurately guess your variable speeds, accelerations, regen braking, how long sitting at a light, how many lights, etc.

BUT.... you will get an average "miles/kWh" for that same around town driving. Start your day with a reset m/kWh meter, and drive your trip. If you're getting 3.5m/kWh, then your range for that trip is based on 3.5m/kWh, not steady speed.

Perhaps the chart should say 60mph *or* 3.9m/kWh. The next time you're on a level road, and traveling 60mph, reset the m/kWh meter and see if it doesn't settle on 3.9 over the course of 5-10 miles. How will you know the road is level? Go to the INFO page, and hit either GPS or "Where am I", each of which should give you elevation data. Steady speed, level highway, no wind, dry hard surface highway.

Yes, the 10mph runs WERE done in a laboratory condition. I filmed it. It CAN be done; if you're in a place where coming up short is not an option, driving about 12.5 mph may get you there. Yes, that would be a quasi-emergency, but at least you have the data to make an education decision on what to do next. I hope you will never paint yourself in that corner!!!

I primarily included down to 10 mph to show folks that the 38 mph number we previously may have thought was the best range speed is not accurate. Range only increases with slower speeds down to about 12.5 mph.

 

[TonyWilliams]

I ended with an average of 3.8 M/Khw (on both meters) and I drove 89.3 miles. Doing the math, that would seem to indicate I used 23.5 Kw from the pack...

I know that my charted number of 81 miles for 3.9m/kWh is a bit low on range. I really think it's about 85-ish, which is still 21.79kWh total usable battery.

Your numbers, 3.8 and 89 miles certainly is right in the ballpark. One HUGE problem we have is using a low resolution number to generate the total usable power.

I'd like to see a 3.8123237287382 kind of number :!:

 

[thankyouOB]

so, are you saying that the number of bars is 12 you can see and 2 that you cant....so multiples are really 14 times whatever you are averaging per bar?