Test route elevation impact?.... 80 meters

[cdherman]

Been reading a lot about testing. Figured out how to use google maps and http://www.gpsvisualizer.com" onclick="window.open(this.href);return false; to show elevation changes. My route in KC is 152 Amity Rd west, to 435 north, to I-29, to 435 South, back to 152 and then to Amity. Nice loop of about 40 miles, and about .5 mile from home. I can also short cut it several places and reduce by 10 or 20 miles so that I can arrive at a test route of 60, 70, 80 or 90 miles if needed.

80 meters in total elevation variation, but quite a few ups and downs. All quite gradual, such that one is aware of a grade, but not really a "hill". Pretty much there is no "level" stretch in the loop, though there are many places where one percieves no rise or fall.

So how much does elevation changes effect a test run? I have read in a couple posts that they "cancel". But, even if there is no regen involved, I would think that the extra work put on the batteries during the climbs is not perfectly evened out by the coasts down.

I don't have access to a really flat strech in the area. Kansas city is not western Kansas!

 

[mwalsh]

So how much does elevation changes effect a test run? I have read in a couple posts that they "cancel". But, even if there is no regen involved, I would think that the extra work put on the batteries during the climbs is not perfectly evened out by the coasts down.

Correct. Unless the coasts down were waaaay further or waaaay steeper than the climbs.

 

[edatoakrun]

Been reading a lot about testing. Figured out how to use google maps and http://www.gpsvisualizer.com" onclick="window.open(this.href);return false; to show elevation changes. My route in KC is 152 Amity Rd west, to 435 north, to I-29, to 435 South, back to 152 and then to Amity. Nice loop of about 40 miles, and about .5 mile from home. I can also short cut it several places and reduce by 10 or 20 miles so that I can arrive at a test route of 60, 70, 80 or 90 miles if needed.

80 meters in total elevation variation, but quite a few ups and downs. All quite gradual, such that one is aware of a grade, but not really a "hill". Pretty much there is no "level" stretch in the loop, though there are many places where one percieves no rise or fall.

So how much does elevation changes effect a test run? I have read in a couple posts that they "cancel". But, even if there is no regen involved, I would think that the extra work put on the batteries during the climbs is not perfectly evened out by the coasts down...

Given your description of the route, and assuming you do it at constant relatively high speed, I would think you might do the entire trip at 15 to 25 kw use. Since the variation in drive-train and battery discharge efficiency is believed to be slight in this range, I would expect you to recover fairly close to 100% of the ascent energy. The problem is, I'd also expect other uncontrolled variables (wind, temperature, etc) will probably make accurate observation of such a small efficiency variation impossible.

FYI, I make a regular "100%" to VLBW range test over a route with ~6,000 ft of ascent and descent. I do have to use quite a bit of regen on the descents, and also due to traffic, stoplights and stop signs. etc. And I have to waste a significant fraction of a kWh in friction braking, early in the trip. My kW use varies from ~35 kW expended to ~30 kW recovery by regen, though of course, I try to avoid high energy use and recovery levels as much as possible.

As near as I can tell (I have the same uncontrolled variables you will have, plus the effects of speed variations which I can only approximate by replicating travel time) I always recover ascent energy somewhere in the range of 80% to 90%, on this route.

I get higher efficiency when I drive at faster speeds, by avoiding excessive regen, though of course I get lower m/kWh due to the greater air resistance.

http://www.mynissanleaf.com/viewtopic.php?f=31&t=9064" onclick="window.open(this.href);return false;

 

[TonyWilliams]

If your slight up and downs don't involve regen (just higher and lower kW consumed), I would call it "close enough".

Check out the range chart linked in my signature line to give you an idea of what affects range, and what range to expect.

 

[TomT]

I read 80 Meters and thought this was a Ham posting... :lol:

-K6TGT