Results matching “LEAF”

At the National Drive Electric Week event in Seattle, Cathy and I saw the newly-announced but not yet available 2018 Nissan LEAF. At that event, we signed up for a test drive.

Today, October 23, 2017, Jose pulled up in front of our house in a beautiful blue Nissan LEAF for our test drive. We spent about an hour going over the vehicle and then out for a drive. Jose was enthusiastic and very knowledgeable about the car. We have a 2011 LEAF, so I'm familiar with that but haven't driven any of the newer LEAFs, so that's my perspective.

Back Seat

The LEAF claims to be a 5-passenger vehicle, but the middle back seat has no head rest, so no neck protection in a rear-end collision. We often have 5 adults in the car, so that matters to us. I've been especially aware of this since we were rear-ended this summer. Fortunately, it was just the two of us in the car at the time, and neither of us were injured. My head hit the head rest pretty hard, so I'm glad it was there. I can't understand why Nissan doesn't protect the middle seat passenger.

Charge Cord

The SV and SL packages include a dual Level 1 (120V)/Level 2 (240V) charge cord. The standard 120V plug comes off to reveal a NEMA 14-50 240V plug.

With so much public charging available now, there's not much need for Level 2 charging away from home, but the dual mode cord means an owner can upgrade their home charging to 240V by just installing a NEMA 15-40 outlet.

Quiet Ride

When we started the test drive, right away I noticed how quiet it is. I'm told it has the same pedestrian warning sound as the 2011 model, but I couldn't hear it or the inverter whine which are pretty apparent in the 2011. I used to think our LEAF was quiet, but the 2018 is amazingly quiet. There was just the barest hint of a sound at low speeds in the driveway, maybe the pedestrian warning or the electronics, but much quieter. Likewise for road noise at freeway speeds, much quieter than our old LEAF.

One Pedal Driving

One of the best things about the electric driving experience is one pedal driving. It's so natural: push the accelerator pedal to go faster, let up to go slower. With regenerative braking, an EV can be much smoother and natural than a gas car, can slow down on a steep hill without using the brakes, and cruise control can hold you at a steady speed up and down hills. Automakers seem to be afraid of taking full advantage of this feature for fear it will be unfamiliar to gas car drivers, but Nissan has fully embraced it in the new LEAF. In the 2018, I was able to bring the car to a full stop on the steepest part of our driveway. Amazing! At the bottom of our drive, I brought it to a full stop, nudged it forward to look around our mailbox for traffic, then eased onto the road, all using just the accelerator pedal.

Nissan calls this feature ePedal. It can be turned on and off, and can be set to on or off by default. So, gas car drivers can test drive the car without it, then turn it on when they are ready to try driving a car with a superior drivetrain. For most people, once you get used to one-pedal driving, you'll find a gas car feels outdated and you'll never want to go back.

Analog Speedometer

The 2018 LEAF drops the large, easy-to-read digital speedometer for a boring analog speedometer. Jose tells me that Nissan thinks people don't like the digital speedometer, that it doesn't provide feedback on acceleration the way an analog speedometer does. I like the digital speedometer and find that having my back pressed into the seat is all the feedback I need on acceleration.

ProPilot

Nissan did a demo of autoparking at the worldwide announcement, but that feature is only available in Japan, not the United States. Jose gave me the lame company line that US drivers don't use the autoparking feature; maybe we'll get it later. I don't know what the real story is, but that's nonsense.

We got on the freeway and I engaged the ProPilot cruise control feature. As with any cruise control, you get to the speed you want then hit a button. The car will keep you at that speed when it can, but responds to traffic and slows down when there's a slower car in front of you, then speeds back up when the road is clear. It also detects the lane lines on the road and keeps the car centered in the lane. Despite being a nice, sunny afternoon with clearly visible lines on the freeway, the car lost the vision lock a few times and I had to take control. It did slow down when a slower car got in front of us.

It seemed to me like the car was keeping us to the left of center in the lane. Maybe its sensors are better than mine, but I found it a little unnerving when we had a giant semi slowly pass us on the left. I didn't like being so close and took control to put us more center-right in the lane.

When we exited the freeway, I left the ProPilot cruise control on which arguably isn't how it's intended to be used. The exit peels off very gradually for a pretty long, straight stretch. That was working fine, the ProPilot was slowing down to match the car in front of us. As the lane made a gradual curve to the right, the car in front of us was no longer directly ahead, so the LEAF tried to resume full speed. It clearly didn't understand that the lane was curving and that slow car was still in front of us. I disabled the ProPilot at that point.

Maybe it would be cool on a long freeway run, but I found the ProPilot to be too unreliable to really relax and let it drive.

Even when the ProPilot isn't engaged, it watches the road and warns you if you drift in the lane. That happened twice to me, once when I was a little off center and again when the road was curving and I thought I was in the right place.

All-Around Camera

When we got back to the house, I tried out the all-around camera (SL package only). When you pop the LEAF into reverse, the center console screen shows both the backup camera and a simulated overhead view that displays the car's full surroundings. I know the LEAF has had a feature like this available for a few years, but it was super cool to see it in action. It was just like there was a camera over the car looking down to show the car's position in the driveway. It's done with four side camera and math, a very nice effect.

Bluetooth Audio

I paired my iPhone 6 up to the car to play some music. That works great, with plenty of volume. The Tesla Model S fails the "enough volume" test when playing Bluetooth from an iPhone. So that was nice.

Premium Bose Sound System

The test drive vehicle was a top-of-the-line SL with all the bells and whistles, including a super-duper Bose sound system which eats up a small slice of the hatch with amplifiers. When I had my iPhone hooked up, I played some Led Zeppelin and found the sound underwhelming. Our Tesla Roadster has a good sound system, with an Alpine headunit we installed. Those Zeppelin tunes sound great there, one of the pleasures of driving the Roadster. Not so much in the LEAF.

Heated Seats

We put in a very early order for our 2011, but then postponed it until they came out with the cold weather package late in the 2011 model year. Heated seats are a big win in an electric vehicle because they are more energy efficient than cabin heating, and the heated steering wheel is a guilty pleasure we love. The 2018 offers heated seats and steering wheel with the all-weather package, but it doesn't heat the rear seats. We use our LEAF in the winter and don't want to leave our rear-seat passengers in the cold. With the bigger battery, using the less efficient cabin heater is less of an issue, but we like offering heated seats to our rear-seat passengers.

Summary

Overall, the 2018 is a huge upgrade from our 2011. Not only the increased range from 84 miles to 150 miles (EPA rated range), but amazing one-pedal driving, nicely improved sound insulation and plenty of cool tech available in the higher package levels. Unfortunately, the lack of a fifth headrest makes us less interested in upgrading to a new LEAF.

Electric vehicles are awesome for local driving. Driving within the single-charge range of an electric vehicle is more fun, more convenient, and cheaper than driving a gas car. Many people are drawn to the idea that they can abandon gas stations, fuel at home, drive 130 miles for the cost of a gallon of gas and all in a car that has a quiet ride and instant, smooth acceleration that can't be matched by a gas car.

Electric vehicle drivers are excited to see the first DC Quick Charge stations coming online. Oregon and Washington have done their part to power up the West Coast Electric Highway allowing electric vehicle drivers to travel I-5 from the Canadian border to the Oregon-California border and take advantage of stations that can charge a Nissan LEAF or Mitsubishi iMiEV from empty to 80% in about half an hour. This greatly increases the usable range of electric vehicles for longer trips and also provides a safety net for rare situations when drivers unexpectedly need more than their normal overnight charge.

Unfortunately, there's a problem that is causing a lot of confusion that can result in a driver getting less charge than needed. Even though the stations are working properly, drivers may think something went wrong because of a user interface issue.

The above is the screen from an AeroVironment DC Quick Charge station in Tumwater, WA, as shown while charging our Nissan LEAF in June. The screen shows the driver two pieces of information: the amount of energy delivered to the car and a charge percent.

The problem is the displayed charge percent: it is not the car's state of charge (SOC) and should not be treated as such by a driver to decide when to end the charge.

It's pretty well known that it's difficult to determine the exact SOC of a car's battery. Even the best estimate of the battery's SOC may be off by a few percent. That's not what's going on here. The SOC value reported to the station is completely artificial and differs significantly from the car's estimate of the true SOC.

In addition to showing the invalid SOC value to the driver, Blink quick charge stations also require the user to choose a station-controlled charge limit. This has two big problems. First, the LEAF wants to control the charge and will stop the charge at either 80% or near 100% based on the battery state at the start of the charge, so even if you choose 100% on the station the LEAF will terminate the charge at 80% if the car was at 50% or less when the charge started. Second, the Blink station doesn't know the real state of charge and therefore cannot know when to stop charging at the point it says it will.

Here's an example. I recently used the Blink quick charge station at Harvard Market in Seattle, WA. I arrived with just over a half charge remaining, which means the LEAF will allow me to do a full quick charge up to near full capacity. After plugging in the car, the screen on the Blink station gave me a choice of charge levels, defaulting to 80%, which was the highest level shown. I had to press a "more options" button to be able to choose a 100% charge. The graph below shows data collected from the resulting 52-minute charge, comparing the car's actual SOC with the SOC shown on the station's screen.

As you can see, not only is the reported SOC higher than the actual SOC, the reported SOC rises more quickly, increasing the gap as the charge progresses. Throughout the entire charge, the SOC shown on the station consistently overstates the actual charge level and the problem gets worse later in the charge period. As the car gets to about 80% actual SOC, the reported SOC jumps up to plateau near 100% and just sits there for the remainder of the charge, even though the car is far from fully charged.

Had I left the default 80% setting, the charge would have stopped when the reported SOC hit 80%, but the car was really only at 73% at that time. A requested 90% charge would have stopped around 80% actual.

Any driver who sees this behavior and doesn't know that the charge percent value on the station is not the SOC would see it jump up to 97%, perhaps watch it sit there for a few minutes, and likely decide that it would be a waste of time to spend any longer waiting for that last 3%. If the driver ends the charge at that point, the car will be missing perhaps 10% of the potential charge. If that last 10% is needed to finish the journey, this could result in a very unhappy EV driver.

It's not clear where this value comes from, but displaying this invalid SOC on the quick charge stations has created user interface problem with unfortunate consequences for LEAF owners, and perhaps iMiEV owners as well.

So to any EV driver using a CHAdeMO quick charge station that shows an SOC percentage:

1. Ignore what the station shows. Put a sticky over it if you have to. Only look at the car's representation of the SOC.

2. If the station offers you different charge levels, choose 100% charge so that you get the car's best available charge level. If you want to stop the charge early for some reason, do it based on the SOC shown by the car.

I'll contact the quick charge station manufacturers to make sure they are aware of this problem. In the meantime, please help spread the word so EV drivers can get the maximum benefit from these highly valued stations.

For charts of two AeroVironment quick charge sessions, see Cathy Saxton's report. More tips for using quick charge stations are available on our Avoiding Quick Charging Pitfalls page.

On Saturday, June 16, 2012, a dozen electric vehicles made the inaugural drive along US Highway 2 over the 4,061-foot summit at Stevens Pass utilizing the newly-installed quick charge stations. Most of these vehicles recorded data for driving and charging; this blog is a summary and analysis of that data.

Cars charging at the DCQC and Level 2 stations in Skykomish, WA.

We have analyzed this data as well as measurements from other driving and have created pages with information on planning an EV road trip, including guidelines for predicting energy use based on drive conditions and tips for avoiding quick charging pitfalls.

Thanks to Ron Johnston-Rodriguez for all his work getting electric vehicle charging stations installed along US 2 and organizing this event.

Route

This event marked the official opening of DC quick charge (DCQC) stations in Sultan, Skykomish, Leavenworth, and Wenatchee, WA. It was also a test of the spacing between stations. Tom had helped with the US 2 electrification process by collecting data for driving this route in our Tesla Roadster in December, 2010, so we had good information on the energy use required for each segment.

With a carefully-orchestrated schedule from Ron, each vehicle was assigned a charging period at each station. This added a unique constraint, as vehicles would not necessarily have sufficient time for a full charge at the DCQC stations. We provided suggestions for a target charge level when departing each location and the expected energy required to comfortably reach the next station. The most demanding segment was the one over Stevens Pass; our guidance included a recommended state-of-charge level at the summit so drivers would know whether they should stop for Level 2 charging at Stevens Pass ski resort.

We got nifty SWAG from Leavenworth and Wenatchee!

Cars

We have data from 8 Nissan LEAFs, 1 Mitsubishi iMiEV, and 1 Tesla Roadster.

The DCQC spacing worked great for the LEAFs.

The iMiEV was able to make the drive with additional charging for the segment over the pass (charging Level 2 at Stevens Pass in both directions and Level 1 at Nason Creek for the westbound trip).

The Roadster can't use DCQC stations, but with its longer range didn't need much extra energy use. Tom was able to "opportunity charge" at Level 2 while we charged our LEAF and participated in the ribbon-cutting ceremonies.

Data

For those interested in all the gory details, the data and analysis are in this spreadsheet (XLS, 214k).

Drivers recorded information on time, distance, energy, temperature, and driving conditions. The details are in the individual EV# sheets. There are summary sheets for driving and charging that compare the data for multiple vehicles.

The iMiEV (EV1 in the spreadsheet) used an amount of energy similar to the LEAFs.

There were three LEAFs with after-market state-of-charge (SOC) meters that enable more precise monitoring of battery state than the factory instrumentation. These meters show the SOC as a percentage, and also in a unit called a "gid," which represents 80 Wh of energy in the battery. The gid values fell nicely in the range of values based on the LEAF's more coarse SOC bars.

We drove our LEAF (EV4) and Roadster (EV4b) together so that we could compare energy use for the same driving conditions. They turned out to be very similar; there is a summary sheet showing the data for both cars together.

Thanks to everyone who collected and shared data: Patrick, Phil, Lee, Jeff & Mary Lynne, Matt & Laura, Bruce, George, and Mike & Kimm.

EV drivers at the US2 DCQC inaugural ceremony in Wenatchee, WA.

Photo by Jessie Lin, WSDOT. Used by permission.

Quick Charging

DCQC stations made it practical to make this trip (and the return) in a single day. We learned several things about the stations with all the data collected by drivers during this event.

One of the most enlightening was confirmation of an observation during our prior DCQC experience: the station-reported SOC is not a useful indication of the car's charge.

When using a DCQC from under 50% to get to 80%, the LEAF's charge rate averaged 400-500 Wh/minute. When charging from over 50% to "full," the charge rate averaged about 200 Wh/minute.

The charging overhead (energy from the station that didn't make it into the battery) was 10-18%.

More details on DCQC are on our page with tips for avoiding quick charging pitfalls.

Driving

For each drive segment, these are the minimum and maximum kWh (and corresponding gids and bars) used between the DCQC stations. The energy use will vary based on speed and weather conditions.

Trip	miles	kWh	gids	bars
Eastbound
Sultan to Skykomish	26.4	7.20 - 8.24	90 - 103	4.5 - 5.2
Skykomish to Leavenworth	51.0	12.24 - 14.88	153 - 186	7.7 - 9.3
Leavenworth to Wenatchee	20.5	2.40 - 2.48	30 - 31	1.5 - 1.6
Westbound
Wenatchee to Leavenworth	22.3	5.60 - 5.84	70 - 73	3.5 - 3.7
Leavenworth to Skykomish	51.0	12.48 - 13.60	156 - 170	7.8 - 8.5
Skykomish to Sultan	26.5	4.80 - 7.04	60 - 88	3.0 - 4.4

Conclusions

The spacing of the DCQC stations along US 2 over Stevens Pass works well for LEAF drivers. Level 2 charging at the pass is either helpful or mandatory for iMiEV drivers, depending on the driving conditions.

We believe that an SOC meter is a valuable tool when making a trip like this, especially when pushing the range limits of the car. Because we'd projected our energy use for each segment and had a meter providing a higher resolution SOC reading, we were able to minimize the amount of time that we spent charging — including successfully skipping one station — and return home with a comfortable buffer.

Cathy and I took an 1,823-mile electric vehicle road trip to attend the Plug In America board meeting in Berkeley, CA, on June 23rd, 2012. Ever since we took delivery of our Tesla Roadster in June of 2009, I've wanted to take it on a long road trip just to have the experience. Over the past three years, the challenge of making the drive from Seattle to California has been greatly reduced. When Rich Kaethler took delivery of his Roadster in San Carlos, CA, and drove it back to Seattle in August of 2009, and Chad Schwitters made his long trek from Seattle to San Diego and back in April of 2010, these were pioneering efforts. Now we have full speed (240V/70A) Tesla charging along I-5 from British Columbia to southern California, which makes it possible to do the Seattle-to-San Francisco drive electrically in just a couple of days.

Hi, this is Cathy; I'm guest-blogging on Tom's page, and he's playing editor this time!

We recently needed to drive approximately 80 miles (one way) to get to clearer skies for viewing the Venus transit. That provided a great opportunity to try out DC quick charging (DCQC) with our LEAF.

We charged up to full in Bellevue using Level 2 charging, drove to the Tumwater DCQC station, charged back to full while we watched the transit, and returned home to Sammamish.

Data Collection

We have one of Gary Gidding's SOC Meters. It shows a state-of-charge (SOC) percent, which it calculates from a raw energy unit reported on the car's CAN bus. The meter can be set to show the raw energy unit, which the LEAF community has dubbed a "gid." It is reasonably well established that a gid represents 80 watt-hours (Wh). Gids are divided by 281 to approximate an SOC %.

Note that the pack kWh is not something that can be directly measured. The car determines this value through sophisticated measurements and calculations, which result in periodic adjustments that are seen as "jumps" in the gids.

Charging

We arrived in Tumwater with 2 bars, or more precisely 61 gids, which translates to 4.88 kWh, or 21.7%.

Since we were under 50%, our (first) DC quick charge brought us to 80%. The car charged for approximately 26:40 minutes, at which point it was showing 226 gids (18.08 kWh, 80.4%). The station reported having provided 14.36 kWh, and the car showed a net gain of 13.20 kWh.

The graph below shows the status each minute during charging. The lower blue bar shows the energy in the car's pack at the beginning of the time interval. The upper red bar shows how much energy was supplied by the station during the time interval. You can see that the total energy (existing + added) closely matches the pack kWh at the beginning of the next time period. (We only logged the station-reported kWh for some of this charge session.)

The SOC % axis is scaled to correspond to kWh values (both graphs).

It is interesting to note that the SOC % reported by the station (gold dots) does not match the SOC % of the car. We are not sure what causes this discrepancy, but we've seen this consistently in subsequent DCQC sessions.

We expected to need more than 80% charge to make it home, and we wanted to see how to handle getting a full charge after arriving at a station under 50%. So, after the first charging session stopped at the expected 80%, we unplugged and returned the connector to the station. Then we initiated another charging session.

Our second DCQC charge took 36:35 minutes, increasing the car's charge to 266 gids (21.28 kWh, 94.7%). The station supplied 3.609 kWh and the car's charge increased by 3.2 kWh.

At the end of the second charge, the battery temperature was registering 6 bars. Ambient temperature was 61° F.

Driving

We have monitored gids and miles driven over several recent drives. For freeway and combined freeway / surface-street driving we see typical energy use in the range of 250 to 280 Wh/mi, with extreme readings as low as 230 or as high as 290.

The image on the left is after we had driven 74 miles from Tumwater to Issaquah. Stopping for dinner won out over completing the drive home and growing more trees.

Data from our drives to and from Tumwater:

miles	Wh / mi	Notes
65.9	251	Bellevue - Tumwater
79.1	235	Tumwater - Sammamish, slow freeway traffic for several miles

Details on a few legs of the trip from Bellevue to Tumwater.

miles	Wh / mi	Notes
23.6	247	Freeway, uneven speeds (traffic, merges, etc), partially rainy
15.7	255	Cruise at 60
7.1	259	Cruise at 60

Gids in Relation to Bars

The bars are based on an approximation of the percentage of the maximum available energy. This maximum varies with temperature as well as with battery age as capacity is reduced.

Therefore, there is not a static gid-to-bar mapping; it will vary based on current conditions. The image on the right shows gid readings that we observed as bars dropped during driving. It also shows a simple approximation of the gid values at the bar transition points. Since the gid values tend to vary a little anyway, those values should be an easy way to get a pretty close approximation to the actual kWh (gids × 0.08) remaining in the pack. (The gid range will be between approximately 20 × bars + 20 and 20 × bars + 40.)

Don't forget that there is some amount at the bottom (2%?) that is unavailable; the car will shut down before letting you deplete the battery that far.

When we got to approximately 50 gids, the LEAF warned us of low charge with the following:

• Warning message ("Battery level is low") on the dot matrix liquid crystal display just above the steering wheel.
• Illumination of the low battery charge warning light (the icon showing a pump with a plug).
• Flashing driving range (affectionately known in the LEAF community as the Guess-O-Meter).

We arrived home with 35 gids remaining and did not see the turtle.

Nissan did a great job with the Leaf, but I do have one gripe: the lack of a state-of-charge meter with enough precision that you can understand how much energy you use and how driving conditions affect efficiency. Having a good SOC meter allows drivers to comfortably use more of the car's range.

Fortunately, there's a strong Leaf community with a lot of smart owners. Generous owners have spent probably thousands of hours decoding the messages available through the Leaf's on board diagnostics (ODB) port, creating software to interpret those messages, and designing hardware to view and log this information conveniently.

About a month ago, I realized my efforts to build a gizmo and contribute to the community effort were stalled while I worked on other projects, so I suggested we buy one of GaryGid's SOC-Meter kits. As long as we were doing it, I thought it would be fun to invite other owners in the area to do a group order.

Cathy liked the idea and organized the purchase and a build party. We got enough interest to order 10 kits, which arrived in time for Cathy to build our meter in advance so she understood the assembly and could help everyone with the build. In addition, she updated the build manual and added photos.

We arranged to meet at a local Maker space, StudentRND, in Bellevue. It's a great shop, with lots of room to work and cool tools like a laser cutter. If you're in the area, we recommend checking them out.

We met on Saturday. Despite the inclement weather (we had to shovel two inches of mostly ice from our steep 500-foot drive to get our Leaf on the road), we had a good turnout. Here's a photo Cathy took early in the process:



A little later, there was more going on as people made progress on their kits. I'm in the back of the photo, working on my iPhone program for logging EV data.



The only barrier to getting the assembly done in a couple of hours is letting the silicone adhesive cure for an hour in the middle of the process. Still, we had a couple of folks finish and test their meters during the meeting. Cathy is putting the finishing touches on an update to the assembly manual with some insights she learned from the party.

The final product is pictured below, including labels that Cathy added to the kits for our build group.



We now have our meter fully installed in the car. It's awesome.

In September, we finally got our Nissan Leaf. We had signed up very early in the process, and could have had a Leaf in the spring of 2011, but we decided to put our order on hold until they offered the cold weather package. It was worth the wait!

It's now our primary vehicle and we've put just over 2,000 miles on the odometer. Here's our review of the experience so far.

The Good

Driving Experience We've been driving electric since 2008, so it's easy for us to forget how much better the driving experience is with an electric drive train. The accelerator pedal on the Leaf gives instant, smooth response: you push, it takes off. There's no waiting for a gear shift, and no slow climb to full acceleration the way you have to wait for a gas car to rev up the engine speed to maximum torque, then have to shift gears and repeat. It's just smooth, rapid acceleration all the way. I'm sadly reminded of this every time I fly somewhere and am forced to rent a clunky gas-burner.

Braking The Leaf also features regenerative braking. In a gas car, if you want to slow down you have to hit the brakes. This costs you money twice: you're throwing away the kinetic energy of the car and you're wearing out your brake pads. With regenerative braking, you use the motor as a generator to slow the car and charge the battery pack, plus you avoid wearing out the brakes. Even more than the cost savings, regenerative braking shines when going down a hill. In a gas car, you have to ride the brakes or downshift. Riding the brakes is bad as it heats up the pads and can present a safety issues on long downslopes. Downshifting, or engine braking, is better except that you have to chose one of a few gears. With regenerative braking, you can smoothly control your speed with your right foot, whether you're accelerating up to speed, or holding your speed going downhill. Friction brakes work just as on a gas car when you need to stop quickly.

Controls The Leaf has a built-in touch screen for controlling the navigation system and the audio system (AM, FM, CD, iPod/MP3 player, and the ability to subscribe to satellite radio), as well as viewing car information and setting preferences. There are tactile controls on the steering wheel for the audio system and cruise control, and tactile controls around the touchscreen so you can control the vital systems by touch without taking your eyes off the road.

Backup Camera The 2011 Leaf SL package adds a backup camera displayed on the large center console screen. With the camera, it's so much easier to back up whether it's out of a parking spot in a crowded lot, backing into a spot, or just being able to back up against an edge or wall when getting out of a tight spot. I'm now spoiled and miss this feature when driving a car that doesn't have it.

Touchless Keyless Entry The Leaf detects the keyfob wirelessly so that when you are right next to the car, you can just push a button on the handle to lock or unlock the doors or the hatch. You don't have to fumble to pull your keys out of your pocket or purse, which is incredibly handy when you have an armload of groceries. It's the same for starting the car, no fooling with a key, you just push a button and the car starts as long as the fob is inside the car with you. The car knows the location of the keyfob with enough precision that it won't let you lock the keys in the car and can warn you with a beep if you get out of the car without turning it off.

Quiet Ride It's widely reported that electric cars are quiet; some even wrongly claim they are silent. Electric cars don't have noisy internal combustion engines that have to be muffled. At low speeds they can be surprisingly quiet, although you quickly learn to recognize their unique sound even when they creep up slowly behind you. At speeds above 20 mph or so, they make the same noise as a typical gas car does, which consists mostly of tire noise.

That's the story outside the car. Inside the car, it's tricky to do a good job of insulating road noise while keeping the vehicle weight low to maximize efficiency and range. Even if you get rid of the dominant road noise, you just make it possible to hear all sorts of little sounds that you wouldn't notice in a less insulated car. This is especially difficult when there's no engine noise to mask other drivetrain noises. This is the reason for the Leaf's unusual protruding headlights: they deflect airflow around the side view mirrors to get rid of a wind noise you wouldn't even notice in a noisy gas car.

Our two other electric vehicles sound just like the Leaf from the outside, but inside the Leaf is a completely different experience, by far the quietest riding car we've ever owned. I haven't seen the data, but I suspect it's on par with heavily sound engineered luxury sedans that cost far more than the Leaf.

Cold Weather Comfort Because the Leaf uses electric power to heat the car, it doesn't have to wait for an engine to heat up before it can start blowing warm air. The cold weather package (now a standard feature on the 2012 Leaf) adds heated seats (front and rear), heated side mirrors, and a heated steering wheel. If you're driving in the cold, there's nothing more wonderfully decadent than a heated steering wheel. With the cold weather package, the heated seats and the steering wheel get warm even faster than the cabin air.

The cold weather package also adds a battery heater for really cold climates. That's not an issue in Seattle where we rarely see temperatures below 20°F, but is important in more extreme climates.

Remote Control and Monitoring Using a wireless communications system called Carwings, we can monitor the car remotely to check things like the state of charge. The system sends us a text message if we pull into the garage but forget to plug in.

We can also tell the car to pre-heat from our phones. This is something that just can't be done with a gas car sitting in your garage where running the engine would fill the garage, and possibly the house, with deadly carbon monoxide. If the car is plugged in, it uses grid power for the pre-heating, so it doesn't reduce our range. Most of the time, our driving is nowhere near any concern about range, so we use the pre-heat feature even when it uses battery power to warm the car for our return after it has been sitting in a cold parking lot.

Fuel Cost At the US average cost for electricity (11 cents per kWh), the Leaf can drive 30 to 35 miles per dollar of electricity. If gas costs $4/gallon, that's the equivalent of getting about 130 miles per gallon, not in a gutless, rattling economy box, but in a quiet, comfortable car with excellent acceleration.

If the savings in fuel cost is applied to a buyer's monthly car payment, the Leaf is an incredibly affordable car.

Convenient Fueling The Leaf is best suited for local driving, which fortunately accounts for more than 90% of the typical American's driving. If you can use the Leaf for your local driving, you'll find plugging in overnight to be far more convenient than going to a gas station. Especially if you share a car, you've no doubt experienced the rude surprise of needing to make a detour to a gas station, spend time waiting in line, and pump gas when you're already running late. The Leaf is fully charged every morning with just a few seconds of effort required to plug it in at night, about as much time as it takes to plug in a cell phone. Charge time varies with how far you've driven, anywhere from a few minutes to eight hours, but it doesn't matter at all because it happens while you're sleeping.

I know many people think charging time will be an issue, but I just laugh when I see people waiting in a 20-minute line to save a few pennies per gallon at Costco. Driving electric, I pay the equivalent of $0.99 per gallon of gasoline and fueling takes just a few seconds of my time per day. I can only imagine how long the line would be if Costco sold gas for $0.99 per gallon. I get that price and I can charge up in my garage where there's always shelter from the elements and never a wait.

The Bad

Nissan has done an amazing job with their first full production electric vehicle. It's the most comfortable car Cathy and I have ever owned. It's a wonderful car, with no competition whatsoever at any price when considering the comfort and convenience it offers plus the liberation of not being hostage to wildly fluctuating gas prices. However, Nissan got it wrong on two important aspects of driving electric. The good news is that new electric vehicle drivers will get all of the benefits mentioned previously before they notice these more subtle shortcomings.

Increasing Range Anxiety Range anxiety is the irrational fear of running out of power even when an electric car has plenty of range for your driving needs. The way the Leaf presents information about the car's state of charge causes range anxiety. The dash shows in large numbers an estimate of your remaining range. That sounds pretty reasonable, but it has to make an assumption about how you will be driving for the rest of the trip. The Leaf assumes you'll be driving the same as you have been for some unknown period of time. Unless you do all of your driving under exactly the same conditions, same steady speed and constant slope, that estimate is going to be wrong pretty much all the time since it fluctuates wildly as conditions change.

The best information we get is a 12-segment display that displays the state of charge in approximately 8% increments. The problem is you can't tell where you are in the bar. Suppose I drive from work to the grocery store and the gauge drops from 8 bars to 6 bars. That could be from the top of bar 8 to the bottom of bar 6 (almost three bars, or 24%) or from the bottom of bar 8 to the top of bar 6 (just over one bar, or 8%). That's a big difference.

While the estimated range can be useful in some circumstances, Nissan should give us a way to display the car's state of charge as a percentage. I understand that there is some inherent uncertainty in computing the precise amount of energy remaining, but the raw state of charge should be presented to the driver with the same precision as the estimated miles. Having this information would help drivers better understand their energy use and increase the Leaf's usable range. This is such an important piece of information that owners have figured out a way to display the state of charge by tapping into the Leaf's on-board diagnostic port.

Denying the Best Feature of Electric Driving The regenerative braking offered by an electric car dramatically improves the driving experience. Once you get feel of driving electric, it's a joy be able to control your speed with just one pedal: push down to speed up, lift to slow down. Whether it's uphill or downhill, speeding up an on ramp or slowing down for an exit, you do it all with the accelerator pedal. It's far more natural than how it works on a gas car, it's just different from how we all learned to drive. Nissan was apparently concerned about making the Leaf feel as much like a gas car as possible so as not to scare away consumers afraid of change. To do this, they have two modes, normal and economy mode. In normal mode, there's a limited amount of regenerative braking on the the right pedal. In economy mode, there's more regenerative braking, but acceleration is dampened out. You can get the same acceleration in eco mode as normal mode, you just have to push the pedal farther down.

I want maximum regenerative braking, so I always drive in eco-mode. This makes the accelerator less responsive unless I really push it. I would much prefer a more typical pedal response with the maximum regenerative braking. It's also annoying that the drive mode doesn't persist, I have to put it into eco-mode every time I start driving.

Conclusion

Nissan clearly leveraged what they learned from making the world's first factory-made lithium-ion electric car over ten years ago* to create an incredible first generation production electric vehicle.

The comfort features of the Leaf make it worth the sticker price, even if it had a gas drive train. With efficiency that can't be matched by an internal combustion engine and fueled with cheap domestic electricity, the savings in total cost of owning and driving the Leaf make it the uncontested winner in value for its class of comfort and driving experience, in many ways superior to all gas-powered cars at any price. Add in the environmental benefits and the satisfaction of knowing your fuel dollars stay in the US instead of pouring into the global oil market that threatens our national security as well as our economy, and no other car on the market offers the value of the Nissan Leaf.

If you're in the market for a new car, and typically drive under 60 miles per day, and already own a gas car that you can use for those few longer trips, you owe it to yourself to test drive a Nissan Leaf before investing in another gas car.

* The all-electric Nissan Altra built to satisfy California's short-lived zero-emissions mandate from 1997 to 2003.

updated 9/6/2011 2:42 pm: added nerdy charge graph

Last week, Cathy and I took the Roadster for a car show and week of island hopping through Washington's San Juan Islands and Vancouver Island in British Columbia. It was a lovely trip and unique in our EV road trip experiences in that we did the entire 450-mile trip using only 120V charging.

We are frequently asked where we charge our electric cars. The question is often accompanied by a pained expression that tries to offer sympathy for the sacrifice we make by driving electric. The answer is: mostly at home. People are frequently surprised to learn we have found it to be more convenient than going to a gas station.

Occasionally, we take a trip that requires charging on the road. That generally requires planning and finding electric vehicle charging stations. For this trip, there were some charging stations available, but they turned out to be both overpriced and unnecessary. We had chosen B&Bs that would allow us to charge from normal household outlets. On one island this was a big help as there were two otherwise equivalent choices: one that wanted to charge us $20 to use $1.60 worth of electricity and another that said we could do it for free. We gave our business to the one that didn't think we were incapable of doing math. Since we were taking a leisurely tour, and mostly on small islands, overnight charging at 120V was plenty for our daily driving needs.

The convenience of being able to fuel up from any outlet became especially apparent when we drove past this gas station in Sooke, BC.

We were on our way to Port Renfrew, some 45 miles further west along the southern coast of Vancouver Island. Had we been in a gas car, this would have been our last chance to gas up before our return, some 90 miles for the roundtrip plus any side excursions. Because we were in an electric car, and outlets are far more common than gas stations, we didn't care.

At Port Renfrew, we were going to be staying in a yurt at the Soule Creek Lodge. We'd contacted them in advance and knew they had an outlet we could use to charge the car. Charging at 120V only yields about 3 to 5 miles of range per hour of charging, which is painfully slow if you are waiting while you charge, but totally adequate if you're sleeping through it.

Our one night there, we picked up 53 miles of range, which was plenty to get us through the next day's driving.

My only regret for the trip was not getting a photo at Wildwood Manor on San Juan Island where we had deer grazing next to our charging car. Somehow you just never see deer grazing at a gas station.

Nerdy Charge Graph

Here's a graph of our state of charge for the trip. It shows the car's range in standard mode ideal miles, which means we can go that many miles at 55 to 60 mph on the highway, with another 25 miles in reserve.

The first steep dive is the 90-mile drive to Anacortes, WA, to catch the ferry. Then there's a flat spot while we wait five hours after missing the cut-off for the unexpectedly popular first ferry by 5 minutes. Over the next three nights, we charged up overnight on Lopez and San Juan islands working back to a full standard mode (90%) charge, then a fourth charge returned us to full again. There are also a couple of little afternoon charges in there. The fifth charge is in Victoria, BC, after which the car stayed parked for a full day, then we did a range mode charge prior to departing for Port Renfrew. The overnight at Soule Creek Lodge got us back up to the top of standard mode (about 190 ideal miles). Finally, the long 170-mile drive home with a short stop for lunch then a longer stop for the ferry ride. We got home with 10 miles of range left (thanks to my heavy right foot as it became clear we had plenty of charge), plus the 25 miles in reserve. The last spike shows the steep slope of 240V/32A charging at home.

A LEAF could do a pretty similar trip. Depending on the starting point, it might need a little charging on the way to Anacortes (like spending an hour or two at a J1772 charging station at the Burlington outlet malls instead of spending five hours in the ferry line). Instead of spending two nights with a full day in Victoria (where we didn't drive or charge), spend one night in Victoria on the way out and the second night on the way back.

How do the Tesla Roadster and Nissan LEAF compare in energy use?

Tesla Roadster owners have been driving electric for a couple of years now and have built up knowledge about how much energy is required for many different routes and driving scenarios. New Nissan LEAF owners could perhaps benefit from what Roadster owners have learned, especially in the near term while charging stations are few and far between.

On August 4, 2011, we did a test to answer a couple of questions:

How does energy use in a Nissan LEAF compare to a Tesla Roadster?

Does knowing how much energy a Roadster uses for a certain drive help a LEAF owner plan the charge needed for a long drive?

The Plan

To take a first stab at figuring things out, Cathy and I joined up with her parents, Jim and Barbara Joyce, to drive a Nissan LEAF and a Tesla Roadster on an interstate freeway up a mountain pass. We wanted to compare just the two cars and eliminate as many other variables as possible. We drove up together so we had identical road and weather conditions, put the cars on cruise control to minimize driver differences, and restricted ourselves to using the fan but not air conditioning. From Roadster data collected on previous drives and also a recent LEAF drive up the same pass, we were pretty confident it could be done from the Joyces' home even cruising at 70 mph. We were right.

The Route

We started at the Joyce residence near where Washington State Highway 18 meets Interstate 90 at Exit 25. Their LEAF started with a full charge. We drove to I-90, recorded trip and energy data at the stop light at the base of the on-ramp, accelerated up to 70 mph, then locked on cruise control. We exited I-90 at Exit 52 and recorded trip and energy data at the bottom of the off-ramp. We puttered around the summit for a bit, got some lunch, then reversed the route, again recording data at the bottom of the on-ramp getting back onto I-90 and again after exiting the freeway back at exit 25.

The Results

The graphs below show energy use for both vehicles up the pass from exit 25 to 52, a distance of 27 miles with a 2,000 foot elevation gain, then the descent back down from exit 52 to exit 25.
The graph shows that the LEAF used about 6% more energy than the Roadster on the way up and about 13% more energy on the way down. Both vehicles used about twice as much energy on the way up as the way down, although that ratio depends on the slope and speed. For a sufficiently steep road and slow descent, an electric vehicle can actually gain net energy driving downhill. At 70 mph, we did not see a lot of energy production, just low energy driving. At slower speeds, more energy would have been produced on the steep sections of the descent.

The LEAF averaged 2.7 miles per kWh (376 Wh/mi) on the way up and 4.8 mi/kWh (233 Wh/mi) on the way down, for an average of 3.3 mi/kWh (305 Wh/mi).

The Roadster averaged 2.8 miles per kWh (355 Wh/mi) on the way up and 5.5 mi/kWh (206 Wh/mi) on the way down, for an average of 3.6 mi/kWh (271 Wh/mi).

How Much Charge is Needed to Drive a LEAF Up to Snoqualmie Pass?

The LEAF doesn't give an indication of the state of charge to any useful precision, so we could only measure energy use from the trip miles and miles per kWh supplied by the LEAF. In terms of how much charge we used, the LEAF started with a full charge and ended back home with one bar showing and 4 miles on the generally worse-than-useless guess-o-meter. This included under 10 miles of driving between the freeway and home. It was a little surprising that the LEAF charge got so low given that the home-to-home energy use was only about 18 kWh, but the reported 24 kWh capacity of the battery is probably measured at a discharge rate that's lower that what's needed to climb the pass at 70 mph. Also, we know the LEAF hides some reserve charge from the driver.

From this data I conclude that starting from a full charge in Snoqualmie or North Bend, a LEAF can easily make it up and down the mountain at the speed limit without climate control. With climate control on, a bit slower speed may be required.

With a DC Quick Charge to 80% at North Bend, it could probably be done by anyone starting in the greater Seattle metro area.

Having Level 2 charging at the summit would be a big help. Even Level 1 would make a difference for someone spending the day skiing at the pass and wanting to get home with little or no charging on the way back.

Driving at lower speeds would use less charge. Really efficient driving, including better use of regenerative braking on the way down, would further decrease the charge needed.

Comparing the Nissan LEAF and Tesla Roadster

The curb weight of the Roadster is about 2,700 lbs, compared to the LEAF at 3,350 lbs. So the LEAF weighs about 25% more than the Roadster. The LEAF has a more aerodynamic shape, but has a much larger frontal cross-sectional area, so I would expect the LEAF to also have more aerodynamic drag. At freeway speeds, one would expect the aerodynamic drag to be a bigger factor in energy use, but doing a significant climb increases the importance of vehicle weight.

Because of how these two issues interact under different conditions, these numbers tell the story only for this specific drive on this route at this speed. Other drives are likely to give different results, so more tests are needed to get the full picture. It would also be interesting to do the same drive with multiple LEAFs and Roadsters to see how much variation there is between vehicles of the same model.

Data Method and Repeatability

We did everything we could both to minimize the difference between the two side-by-side drives and also standardize the drive so it could be repeated later under either similar or different conditions.

It was warm enough that we had to run the car fans to stay comfortable, but we were able to avoid use of the air conditioning.