How to plan route with elevation in mind?

[Stunt822]

I can't belive Carwings route planned doesn't use elevation. Is there another web site/tool to do that? My story - planning a 50mile trip, with some but not alot of recharge at the destination. I want to check how much elevation gain each path offers - and don't know how.

 

[kovalb]

Not perfect, but Google Maps has a feature that can display terrain. There is a drop down box where it says "traffic", then select "more" and you will see the "terrain" option. It seems to only be a visual representation, not elevation numbers, but at least it is something.

 

[Devin]

You can use this website in conjunction with Google Maps...

http://www.gpsvisualizer.com/profile_input

Just copy the link from a Google Maps directions page into the "Or provide the URL of data on the Web" box and it'll plot it for you.

 

[DarkStar]

Hmm... I seem to recall an awesome thread on plotting better maps...

http://www.mynissanleaf.com/viewtopic.php?f=38&t=3721

 

[Devin]

Hmm... I seem to recall an awesome thread on plotting better maps...

http://www.mynissanleaf.com/viewtopic.php?f=38&t=3721

I knew I got that somewhere on here, but I couldn't find it earlier. Thanks for posting the link!

 

[TimLee]

The University of Tennessee Chattanooga Center for Energy, Transportation, and the Environment did some work on this. Briefly covered in electric vehicle symposium I attended there in 2009. But I don't know the latest on their work in this area.
Their work was more focused on plotting an accurate vehicle range map that took into account terrain, than analyzing energy use for alternative routes, but its the same general concept.

 

[JimSouCal]

Moreover, the wide varying range as a function of going up is what confounds me sometimes when I am trying to plan my routes. Plus regen at speeds above 30MPH has less and less of an add as one goes faster and spends the energy overcoming rolling and wind resistance.

If one knows their planned driving speed, and elevation changes, there **must be a way** to factor in the elevation with some good predictive results, but this is beyond me. I do know that going up 2000 feet or so really eats the battery charge. My seat of the pants guess could use a mathematical approach for sure.

Even when I know the elevation change, my range planning could use some help...

 

[edatoakrun]

I live and drive in the "inter-mountain region" of Northeast California. I haven't had a day of driving with less than 2500 ft (down and back up) of elevation change since I drove home from the Bay area 3 months ago. The guess-o-meter is nearly useless. It shows 30-something miles of range at home with a 10-12 bar charge, then climbs to over 100 miles after I descend 2000 (1500 net) ft in the first 7 miles.

I have found that when driving in eco at speeds of 45 to 60 mph, at 10 bars or less of charge (allowing full regen) regen ads about 1 bar of range for each 1,000 ft of descent, and subtracts about 1 bar for each 800 ft of ascent.

Try calculating your level drive range, then adjust accordingly for net elevation change, and see how this works for you.

 

[thimel]

There is a wonderful website at http://www.rechargeamerica.net/progs/stateofcharge/road2.html which does a full physics simulation of electric or hybrid vehicles. It includes speed, elevation changes, climate control and many other factors. It will predict how many kWhr it takes to do a trip. It was written by Karen Pease who then went on to form a company called Celadon to market the technology. She has filled in all the parameters for a Tesla and compared the results to real drives and gotten good results.

The catch is that there are no parameters for a LEAF and she won't be creating them any time soon. However, the web site allows one to enter parameters and they can then be submitted to her for inclusion in the program. If someone or a group of people are interested in putting in the parameters (Warning, there are a LOT of parameters) and testing the results against their LEAFs (probably need a state of charge meter), then this could become a useful range calculation for LEAF owners.

 

[planet4ever]

I have found that when driving in eco at speeds of 45 to 60 mph, at 10 bars or less of charge (allowing full regen) regen ads about 1 bar of range for each 1,000 ft of descent, and subtracts about 1 bar for each 800 ft of ascent.

What a beautifully simple way to look at it! Thank you. I must admit to being surprised that regen is as efficient as you say, but you certainly have the experience to back up your claim.

Ray

 

[TonyWilliams]

I have found that when driving in eco at speeds of 45 to 60 mph, at 10 bars or less of charge (allowing full regen) regen ads about 1 bar of range for each 1,000 ft of descent, and subtracts about 1 bar for each 800 ft of ascent.

What a beautifully simple way to look at it! Thank you. I must admit to being surprised that regen is as efficient as you say, but you certainly have the experience to back up your claim.

The parameters for subtracting and adding eFuel bars are different. When a bar disappears during fuel "burn", the next bar up is "fully charged" and will remain lit for as long as there is any energy in that bar. When it is completely depleted, it too, will disappear, and so on.

If you burn into that next bar, and then turn the car off, and then back on, it's likely that the bar will not reappear, as it is not full.

Adding a bar does not meet the same standard as depleting one. It will get to approximately half full and illuminate.

The regen is not quite as efficient as it may have seemed.

 

[Nekota]

Consider the potential energy U = mass * G * height. Using 3350 lbs for mass, 9.8 m/sec^2 for g, and a height of 1000 feet I get about 1.25KWHr for each 1000 feet of elevation. If the LEAF is 80% efficient going up and 80% efficient with regen coming down, I estimate the elevation requires approximately 1.6KWHr to go up 1000 feet and would return approximately 1.0KWHr on descending.

I can't find the link about the estimated KWHr/Bar capacity but 1.7 seems to be what I recall.

 

[TonyWilliams]

I can't find the link about the estimated KWHr/Bar capacity but 1.7 seems to be what I recall.

I think many of us believe about 1.5 per bar; 21kWh usable battery available divided by 14 units (12 bars plus Low Battery and Very Low Battery).

 

[JimSouCal]

I have found that when driving in eco at speeds of 45 to 60 mph, at 10 bars or less of charge (allowing full regen) regen ads about 1 bar of range for each 1,000 ft of descent, and subtracts about 1 bar for each 800 ft of ascent.

Try calculating your level drive range, then adjust accordingly for net elevation change, and see how this works for you.

Thanks for sharing your experience. When driving Topanga Canyon Road, for example, I am going to pay better attention on the rise and fall. On that run, going up seemed to eat 2-3 bars, and coming down, gain one.

Why the car did not come standard with a SOC meter display mode is seemingly a nit to pick.

 

[edatoakrun]

I do not mean to suggest that regen is 80% efficient, or that the addition or removal of bars corresponds exactly to SOC. These topics have been covered on other threads.

I was simply suggesting a way to correct the bars/range calculation estimate for altitude. Obviously, it will be inexact, due to road variations and "micro" regen/acceleration events due to traffic, curves, dips and rises, etc., and likely more accurate over longer drives.

for example, my "commute" is a 50 mile round trip, beginning with about a 2000 ft (1500 net) descent in the first 7 miles. If I start with 10 bars or less, the first bar typically disappears at about 14 miles, then 2 more are used in the next 11 miles (flat at 55-60 mph).

The return trip uses the same 2 bars for the first 11 miles, then 3 more for the remaining 14 miles.

On longer trips, the estimate has also worked for me.

For example, on my first drive to Shasta NP, it took 10 bars to cover 42 miles and about 5,500 ft (5,000 net) of ascent, but only 1 bar was consumed on the same route while descending.

Remember, I'm not suggesting regen is 80% efficient. When you are descending on a (not too steep) road at 45-60 mph, most of the time you are applying light "throttle", and are not in regen mode, which you should avoid for best efficiency and range.

While regen is probably a lot less than 80% efficient, my experience is that you can typically regain about 80% of the total energy consumed in your ascent, when you descend on the identical route.

Some of you with SOC meters could probably expand on this.

 

[HighDesertDriver]

Consider the potential energy U = mass * G * height. Using 3350 lbs for mass, 9.8 m/sec^2 for g, and a height of 1000 feet I get about 1.25KWHr for each 1000 feet of elevation. If the LEAF is 80% efficient going up and 80% efficient with regen coming down, I estimate the elevation requires approximately 1.6KWHr to go up 1000 feet and would return approximately 1.0KWHr on descending.

I can't find the link about the estimated KWHr/Bar capacity but 1.7 seems to be what I recall.

:!: Excellent :!: We don't have our Leaf yet, but the effects of elevation change have been on my mind for those trips when we venture out of this high desert valley. The nice thing about Nekota's post is that it shows the theoretical maximum kWh input/output for just the altitude change and then adjusts for approximate inefficiencies. Those tempted to stretch a trip in the vain hope of getting more than ~1.25kWh will be violating the laws of physics and find themselves at the side of the road. Those daredevils hoping for 80% efficiencies had better hone their driving skills first and have backup plans. As for us, we'll be maintaining a conservative margin until we have a lot of first-hand experience.

 

[DaveinOlyWA]

droid app "get altitude" works fairly well. gives spot by spot altitude measurements. would be a bit tedious since there is no mapping function with it.

 

[edatoakrun]

Consider the potential energy U = mass * G * height. Using 3350 lbs for mass, 9.8 m/sec^2 for g, and a height of 1000 feet I get about 1.25KWHr for each 1000 feet of elevation. If the LEAF is 80% efficient going up and 80% efficient with regen coming down, I estimate the elevation requires approximately 1.6KWHr to go up 1000 feet and would return approximately 1.0KWHr on descending.

I can't find the link about the estimated KWHr/Bar capacity but 1.7 seems to be what I recall.

Perhaps my observation that it seems to take about 1 bar for each 800 ft of elevation gain reflects both a lower actual kWh/bar capacity (1.5?) and the fact that my LEAF generally has a driver in it when in motion...

In fact, given that I am somewhat "gravitationally challenged", the gross weight of my LEAF with myself and average cargo aboard is probably about 3650 lbs.

 

[DaveL]

Consider the potential energy U = mass * G * height. Using 3350 lbs for mass, 9.8 m/sec^2 for g, and a height of 1000 feet I get about 1.25KWHr for each 1000 feet of elevation. If the LEAF is 80% efficient going up and 80% efficient with regen coming down, I estimate the elevation requires approximately 1.6KWHr to go up 1000 feet and would return approximately 1.0KWHr on descending.

I can't find the link about the estimated KWHr/Bar capacity but 1.7 seems to be what I recall.

I have been been using the 1.6 KWH per 1000' elevation gain to estimate range this summer climbing up and down the Washington Cascade mountains and find it to be pretty accurate. How much gets regenerated for every 1000 feet of drop is harder for me to determine as I don't have an SOC gauge, but 1 KWH seems about right.

Also, I've find the 1.7 KWH per bar to pretty accurate as well.

How many bars gets used climbing is not only the elevation gain, but also the distance traveled, the speed of the car and the ambient temp.

I consistently use 10 bars to travel the 44 miles between Enumclaw and Chinook pass for a elevation climb of 4650 feet at an average of 45 mph in 60-70 degree temps. The return trip requires 2 bars.

Also, I consistently use 5 bars to travel the 19 miles from our Cabin to to Chinook pass for an elevation climb of 2500 feet at an average of 47 mph in 60-70 degree temps. The return trip regens more than is used, but rarely results in an extra bar.

Dave

 

[wishboneash]

One of the great things about the Leaf is that the power of the car has little bearing on the absolute altitude unlike an ICE car which loses HP as it operates at higher elevation (assuming non-turbo charged).