Trip report: 4800 ft. climb, 100 mi.

Yesterday I went for a little road trip in Leaf, from Exeter up to Camp Nelson. This involves 30 miles of level highway and then 20 miles of twisty climbing to reach Camp Nelson at elevation 4800 ft. To see a map of the route: http://tinyurl.com/44p8pxk

Started off with a 95% charge and set cruise for 57 mph. After a few miles, lowered it to 55 mph. After Springville, the road begins to climb with some steep sections, but the road is twisty so the going is slow. Average speed for the climb is about 30 mph due to the twistyness of the road. The Leaf is actually a great climber, as the electric motor puts out high torque and it is very responsive. One car pulled over into a turnout to let us pass, and instantly we accelerated up the hill and had passed them - effortlessly. I had a theory that the slower going would offset the increased energy required to climb, and it seems to be true. Also, every time we slow for a curve energy goes back into the battery. Those with hybrids are probably used to this, but it's cool nonetheless. Reached Coy Flat Campground in Camp Nelson with one bar to spare, and a 6 mile range estimate.

After a short hike, it was time to go back down. I was really curious how much energy the regenerative braking could recover on the way down. It did not disappoint. Going downhill in ECO mode is like downshifting into 3rd gear - except you recharge your batteries in the process! Based on the display, it seems to regenerate at a rate of about 12 KW with foot off the pedal. Putting on the brakes makes it regenerate more, but I don't know when the friction brakes kick in so I tend to avoid that. At the bottom of the hill in Springville, regenerative braking had increased the estimated range to 22 miles.

Knowing that would not be quite enough to get back home, I set cruise to 40 mph most of the way. I stopped for an hour at a friend's house in Lindsay to trickle-charge, then continued the remaining 8.4 miles home. Just as we entered Exeter, the display changed to triple-dashes. Apparently we got home just before it would have entered turtle mode. Total trip distance was 99.7 miles.

Now, looking back, there are a few things I could have done better: (1) I should have topped-up to 100% before leaving. (2) I should have gone slower - at 50 mph the range would have been significantly greater than at 57 mph. (3) There was a cabin near the trailhead where I could have trickle-charged. Any one of those three would have made it possible to do the trip without having to stop in Lindsay.

The takeaway is that the Leaf performs very well on the hills - and thanks to regen, does not use noticeable more energy than on flat land

That's great to hear. Where I live is very hilly. My Civic Hybrid is horrible on the hills when the battery is low.

There was a point when I almost didn't make it through the light from a stop going uphill.

A couple of things to remember:

The range estimate is based on a snapshot of your recent driving. Thus, even if you had not regenerated a single electron on the way down, your range would have been much higher at the bottom of the hill due to your changed driving style.

Regen is by no means 100 percent efficient. Thus, it definitely does use more energy on hills than on a flat surface.

johnr said:

At the bottom of the hill in Springville, regenerative braking had increased the estimated range to 22 miles.

The takeaway is that the Leaf does very well on the hills, and doesn't use any more energy than on flat land - thanks to the regen

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mogur said:

A couple of things to remember:

The range estimate is based on a snapshot of your recent driving. Thus, even if you had not regenerated a single electron on the way down, your range would have been much higher at the bottom of the hill due to your changed driving style.

Regen is by no means 100 percent efficient. Thus, it definitely does use more energy on hills than on a flat surface.

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Very true - and I noticed that it did not regenerate quite as much as I had hoped. But the combination of slower speed and regen resulted in a range that was actually slightly greater than what I get on flat land.

johnr said:

Knowing that would not be quite enough to get back home, I set cruise to 40 mph most of the way. I stopped for an hour at a friend's house in Lindsay to trickle-charge, then continued the remaining 8.4 miles home. Just as we entered Exeter, the display changed to triple-dashes. Apparently we got home just before it would have entered turtle mode.

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I think your assumption is wrong. Edmunds went nearly 10 miles (at 35 mph) after the display changed to triple-dashes before the turtle came on. JimmyDreams went "2-3 miles" between triple-dashes and turtle, and that was with the heat turned up to max to try to burn off energy. Both of these reports were with cars that didn't have the April firmware update, and we know that update affected when bars turn off, but no one seems to be claiming that the update changed the timing of low battery, very low battery, and turtle modes. Your Lindsay trickle charge only gave you about 5 miles, so my guess is that you would have made it home even without the stop.

Of course I don't know how far it is from "entered Exeter" to your home, but unless Exeter has grown a lot since I went to high school there, or you really live at one of the orange groves north of town, it couldn't have been very far!

Ray

That's good to know. So even after the triple dashes there's still a few miles of emergency reserve. Of course, better safe than sorry.

I got my Leaf five days ago. Yesterday, my wife and I decided to "go for a ride." What a concept. The car had 36 miles of RF left. I headed up into the Oakland Hills and watched with alarm as the number dropped precipitously to 19 after about 5 miles of a steady climb. Not wanting to trust that the numbers would come back up, I turned around, and by the time we got back down the hill I was back up to 27 miles. It's going to take a little time for me to learn how to extrapolate these numbers to a more reasonable estimate of the actual remaining range.

Thank you for the trip report! Driving the LEAF on mountain roads can be a lot of fun; most of our 1000+ miles to date have been in the mountains. So far, we have stopped at Nissan dealers near the base of our mountain and "topped off" to 100% prior to each of our ascents, preferring to err on the side of caution. What I find interesting about your experience is that you had a 30 mile drive before you started climbing. In my case, that would be roughly equivalent to leaving Ontario Airport (ONT), elev. 1000', with a full charge, and driving the 46 miles to my house, elev. 6100', without stopping along the way for a top-off. I intend to try this, as I could always stop for L1 at a friend's house at the 5200' level as a backup.

Our biggest issue thus far has been regenerative braking down the mountain due to starting with apparently too high an SOC (80% or above). We've ended up doing more friction braking than we'd like. Next time we will try starting with roughly 60% or 70% SOC. My goal is to find the maximum starting SOC at which we won't lose any regen.

oakwcj said:

I got my Leaf five days ago. Yesterday, my wife and I decided to "go for a ride." What a concept. The car had 36 miles of RF left. I headed up into the Oakland Hills and watched with alarm as the number dropped precipitously to 19 after about 5 miles of a steady climb. Not wanting to trust that the numbers would come back up, I turned around, and by the time we got back down the hill I was back up to 27 miles. It's going to take a little time for me to learn how to extrapolate these numbers to a more reasonable estimate of the actual remaining range.

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Congratulations on your LEAF purchase! Regarding the range estimates, we've learned to ignore them when driving in hilly or mountainous terrain. It's better to get used to looking at the "gas gauge", i.e., the number of bars of charge. The range estimate number is more or less an extrapolation based on your recent driving and the state of charge. The algorithm does not consider your intended route and/or upcoming altitude changes. (Maybe it should in Gen 2.)

At the bottom of the hill in Springville, regenerative braking had increased the estimated range to 22 miles.

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How many bars did you gain?

Mx5racer said:

At the bottom of the hill in Springville, regenerative braking had increased the estimated range to 22 miles.

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How many bars did you gain?

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Same question I wanted to ask as well.
I've been doing some mountain driving from Los Gatos to Santa Cruz on highway 17 and back with elevation difference as much as 1800ft and one thing I noticed is that I never don't gain any bars on a descending ride (with almost no braking use). Last time I lost 3 bars on the way up and then lost no bars on the way down to the ocean level.

I drove up to Hatchet mountain pass on HWY 299E yesterday.

24 miles up, about 4,000 ft of elevation gain total, with 2,400 ft net.

Used 6 bars from 100% charge. I returned by a slightly different route, used 2 bars (4 remaining). In both cases I lost the last bars very shortly before destinations.

I have never regenerated a bar, after quite a few hills. It looks to me that one bar translates into about 2,000 ft of elevation gain (didn't someone calculate-long ago-that this should be more like 700 ft per KWH?). While regen obviously does not recapture 100% of this energy in descent, my crude "bar" calculations indicate you can get most of it back.

It also seems to me that you would need about 2,000 ft of "ideal" descent, constantly steep enough to avoid battery use, and not so steep as to use friction braking, to add a bar. Does this match your experiences?

I'd need to recharge in Redding Ca to get to Buckhorn summit, on 299W, to get to the closest "ideal" descent of over 2000 ft. I'll copy and email this to a Redding LEAF owner, and suggest he take a drive...

Mx5racer said:

How many bars did you gain?

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If I remember correctly, I gained two bars, but the second one disappeared soon, so I guess it was between one and two bars.