Range Chart

I find all the discussion, calculations, and personal systems for estimating range fascinating and informative, but I recently discovered the best range estimate is already provided by Nissan... It's the white range circle on the Nav display!

Bear with me here. After much data gathering and observation. I've proven to my satisfaction that the following are true:

1. The only thing that really matters is how many miles you actually travel for each bar shown on the battery gauge.
2. Obviously the number of miles you get per bar varies, but you can reset the trip odo's to keep track.
3. The car is keeping track of this and uses an averaging algorithm to drive the inner white range circle display.
4. This "white circle" display is the REAL range you will get despite the other 'optimistic' figure displayed in the cluster.

So here's the deal. That 'optimistic' number on the cluster is really nothing more that what MIGHT happen and it appears on the Nav range display as the outer "gray" circle. It is the "best case" scenario whereas the inner white circle range on the NAV display is the minimum range as predicted by the ACTUAL miles you are getting per bar. In my experience it is the inner range bar that is highly accurate and easy to use and track!

Check it out for yourself and let me know if what I have observed holds true!

johnr said:

Also, have you determined what is the most efficient speed? Is it indeed 38 mph? Or maybe something slower?

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No, probably never going to do that. For many reasons. One, is that we don't have anything flat in San Diego... anywhere. If we did, I probably would do the testing, mostly to see if I could bump that speed up (or range up) with common sense mods, like increasing the tire pressure, perhaps lowering the car a bit, then some of the tricks hyper-miler folks do (fairings around wheels, boat tail, etc.).

Maybe a LEAF driver in Kansas will give it a try, if they can find a no wind day !!!

pkitchen said:

4. This "white circle" display is the REAL range you will get despite the other 'optimistic' figure displayed in the cluster.

So here's the deal. That 'optimistic' number on the cluster is really nothing more that what MIGHT happen and it appears on the Nav range display as the outer "gray" circle. It is the "best case" scenario whereas the inner white circle range on the NAV display is the minimum range as predicted by the ACTUAL miles you are getting per bar. In my experience it is the inner range bar that is highly accurate and easy to use and track!

Check it out for yourself and let me know if what I have observed holds true!

Click to expand...

Unless I've misread the manual, the inner "white" circle is effective round-trip range, and the outer "gray" circle indicates the one-way range from the current location. In practice, sticking to destinations in the "white" circle should always get you back to home base for a recharge.

I had 8 miles of juice left after getting home from work last night..I always take the dogs to the dog park at 12 midnight, the dog park is 7 miles away..I decided to gamble and take the dogs to the park in the Leaf..
It was 95 outside @ midnight so that must of helped my short trip to the park..So I leave for the park @ 8 miles and drive no faster then 30 mph and arrive @ the park with 7 miles left and then drive home and only lose one more mile of charge with 6 miles left..

I used 2 miles of juice on a 7 mile trip This tells me that my 8 mile reserve was based on the 45 miles per hour I had just driven for 30 miles..

Im thinking that I could of gone possibly 15 miles on that 8 mile reserve if I continued to drive very slow..

The white circle is range as a bird flies. It doesn't take into account the bends in the roads.

In contrast with what a few others have posted, I've found that in most cases my best range reference is actually that number next to the bar graph! Assuming reasonably constant speed, the car is very accurate and precise in indicating how many miles remain. Even in varying speeds and conditions, I find that after going a few miles it has gathered sufficient data to become quite accurate. And this number updates constantly with a one-mile resolution, unlike the bar graphs which have a resolution of about 8 miles.

johnr said:

I've found that in most cases my best range reference is actually that number next to the bar graph! Assuming reasonably constant speed, the car is very accurate and precise in indicating how many miles remain.

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Which bar graph? Have you run the car to turtle to verify those numbers?

johnr said:

In contrast with what a few others have posted, I've found that in most cases my best range reference is actually that number next to the bar graph! Assuming reasonably constant speed, the car is very accurate and precise in indicating how many miles remain.

Click to expand...

Unless you run it till turtle you won't know that. The basic problem with Leaf's range calculation is that it places too much emphasis on recent driving. That means, unless you live where the speeds are very similar (say near a freeway, with mostly freeway travel) and flat, it is going to be misleading.

Ok, I've tossed out revision 3 of my range chart. I've used the 21kWh of usable battery power that many have adopted. Also, I added the average kW based on the 21 number for each speed as suggested.

Even if there turns out to be closer to 21.6kWh available, I also think my speed 60mph column may be several miles short of overall range (over the 81), making the 3.9kW burn rate about the same.

I put a small number next to each range to indicate the miles available in that fuel bar, and adjusted the number 1 and 2 bars a bit.

Finally, I added a zero fuel bar that is just a note about transitioning to LowBatt from fuel bar 1. Several other changes, too.

Thanks Tony! I really appreciate the charts.

evnow said:

Unless you run it till turtle you won't know that. The basic problem with Leaf's range calculation is that it places too much emphasis on recent driving. That means, unless you live where the speeds are very similar (say near a freeway, with mostly freeway travel) and flat, it is going to be misleading.

Click to expand...

What would the alternative be? In order to predict range, the car would need to know where you were going (I use the Destination setting less than 5% of the time), as well as your planned speed, the topography details, and the traffic situation (XM here in Los Angeles only has freeway info, not city streets).

Nissan's "future performance is likely to resemble past performance" approach seems the only practical option here. Everyone realizes by now that if they drive 10 miles toward a freeway, then get on the freeway and drive 70+, their indicated range is going to basically collapse before their eyes. Absent a way to notify the car before you leave the driveway, that that's where I'm headed and how fast I'm going to drive, the Leaf is doing the best it can.

I'm curious what caused you to accept 21Kwh as the usable... My experiments to dead with a recharge to 100 percent have consistently shown that I put close to 24Kwh of power back in to the battery (after subtracting charger efficiency - about 26.67 KwH from the wall)... The EPA's numbers show the same. So, as far as I am concerned, based on my experiments and measurements - and those of others, it is a 24Kwh usable pack...

TonyWilliams said:

Ok, I've tossed out revision 3 of my range chart. I've used the 21kWh of usable battery power that many have adopted. Also, I added the average kW based on the 21 number for each speed as suggested.

Click to expand...

mogur said:

I'm curious what caused you to accept 21Kwh as the usable... My experiments to dead with a recharge to 100 percent have consistently shown that I put close to 24Kwh of power back in to the battery (after subtracting charger efficiency - about 26.67 KwH from the wall)... The EPA's numbers show the same. So, as far as I am concerned, based on my experiments and measurements - and those of others, it is a 24Kwh usable pack...

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See here

http://www.mynissanleaf.com/viewtopic.php?f=31&t=4344

Essentially, if you accept that m/kwh shown on the dash is correct - then about 21 kWh is what leaf shows as usable. This has been verified using stats from many.

TonyWilliams said:

Ok, I've tossed out revision 3 of my range chart. I've used the 21kWh of usable battery power that many have adopted. Also, I added the average kW based on the 21 number for each speed as suggested.

Click to expand...

Looks good - esp. I like the Turtle explanation.

Some things to be corrected, though :
- The top says 24kw/h battery. Should be changed to 21 and kWh (not kw/h).
- 6.4kwh, 5.2kwh etc should change to 6.4 m/kWh

Also, only a constant 38mph run might give 138 mile range. I think that 38mph mentioned along with other range by mph figures, confuses people (eg. why does 25 to 45 mph give only 108 miles if 38 gives 238 ?).

I believe the total KwH of power put in to the battery when charging to be a more reliable indicator of capacity since it leaves little room for error or interpretation... Basically, the only variable is the actual charger efficiency, but that is pretty well known at this point. My numbers from TED have been very consistent in this regard and show close to 24KwH usable when I run it down to dead or turtle...

evnow said:

Essentially, if you accept that m/kwh shown on the dash is correct - then about 21 kWh is what leaf shows as usable. This has been verified using stats from many.

Click to expand...

EricH said:

What would the alternative be? In order to predict range, the car would need to know where you were going (I use the Destination setting less than 5% of the time), as well as your planned speed, the topography details, and the traffic situation (XM here in Los Angeles only has freeway info, not city streets).

Nissan's "future performance is likely to resemble past performance" approach seems the only practical option here. Everyone realizes by now that if they drive 10 miles toward a freeway, then get on the freeway and drive 70+, their indicated range is going to basically collapse before their eyes. Absent a way to notify the car before you leave the driveway, that that's where I'm headed and how fast I'm going to drive, the Leaf is doing the best it can.

Click to expand...

I've talked about other options Nissan has in multiple posts.

If a destination is entered, Leaf can figure out the range using known speeds, traffic, topology etc along the route.

If no destination is entered, they can use previous trips' average m/kwh instead of last 5 or so miles to calculate the range. When someone recharges and leaves home, invariably Leaf shows high miles since, likely the drive to home was using lower speeds than average.

There are other things Leaf can do - for eg., if I just drove down a hill and there isn't another hill to drive down nearby (or altitude is already 50 ft, not 500 ft like it was ), Leaf can just ignore that regen since it is a one off. It shouldn't increase my range from 90 to more than 110 like it does on my drive to work (on 80% charge).

Essentially, Leaf can become smart about the car's environment when predicting range rather than using a very premitive and simple algorithm it uses now.

A number of Garmin units now use predictive algorithms whereby it watches where you drive, how you drive, and how traffic varies from day to do, even if you are not using it for destination guidance. It then uses this info to pick the best route and give a better prediction of travel time when you do set a destination or route. Nissan could and should do the same with the Leaf Nav...

evnow said:

Essentially, Leaf can become smart about the car's environment when predicting range rather than using a very premitive and simple algorithm it uses now.

Click to expand...

mogur said:

A number of Garmin units now use predictive algorithms whereby it watches where you drive, how you drive, and how traffic varies from day to do, even if you are not using it for destination guidance. It then uses this info to pick the best route and give a better prediction of travel time when you do set a destination or route. Nissan could and should do the same with the Leaf Nav...

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Exactly - esp the part about travel time i.e. Garmin is predicting your avg speed and that is one of the important inputs Leaf needs to figure out the range.

mogur said:

I believe the total KwH of power put in to the battery when charging to be a more reliable indicator of capacity since it leaves little room for error or interpretation... Basically, the only variable is the actual charger efficiency, but that is pretty well known at this point. My numbers from TED have been very consistent in this regard and show close to 24KwH usable when I run it down to dead or turtle...

evnow said:

Essentially, if you accept that m/kwh shown on the dash is correct - then about 21 kWh is what leaf shows as usable. This has been verified using stats from many.

Click to expand...

Click to expand...

Have to strongly disagree. Everyone is simply guessing about charger efficiency. At least the 21 kWh number is useful when combined with the dash mpk.

TonyWilliams said:

johnr said:

I've found that in most cases my best range reference is actually that number next to the bar graph! Assuming reasonably constant speed, the car is very accurate and precise in indicating how many miles remain.

Click to expand...

Which bar graph? Have you run the car to turtle to verify those numbers?

Click to expand...

that is the same number on the driver dashboard.

thankyouOB said:

TonyWilliams said:

johnr said:

I've found that in most cases my best range reference is actually that number next to the bar graph! Assuming reasonably constant speed, the car is very accurate and precise in indicating how many miles remain.

Click to expand...

Which bar graph? Have you run the car to turtle to verify those numbers?

Click to expand...

that is the same number on the driver dashboard.

Click to expand...

That's the number that you think is super, mega accurate?

Not only myself, but virtually anybody here will disagree. So, when I start in the morning showing 100 miles on the "Guess-O-Meter", I should just go 100 miles... right? Even when it drops to 70 miles in 5 miles of driving?

I think you're just pulling our leg. But, if that's what you believe, happy motoring then !!