Results matching “electric vehicle”

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.

Charging an electric vehicle is pretty easy: just like my cell phone, I plug it in when I get home and it's fully charged in the morning. It doesn't matter how long it takes because I'm not waiting for it to finish; the car just charges up and waits for me.

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.

I've been driving electric vehicles since 2008, logging over 50,000 miles, and have never had an experience where my vehicle's lack of engine noise created an unsafe situation. However, the issue of quiet vehicles and pedestrians is subtle and complex.

I have had a pedestrian walk backwards through the traffic lane in a parking lot while carrying on a conversation with someone across the lot. She didn't notice my vehicle, but I was watching where I was driving and going slow enough to react to her carelessness. I just stopped and waited about 30 seconds for her to see me. She of course made a rude comment blaming me for the unsafe situation she caused.

I've also had many times when driving through a parking garage where pedestrians are walking up the middle of the traffic lane, totally oblivious to my presence. However I find that happens with about the same frequency it did when I was driving gas cars, which I attribute to the echoing in concrete garages making it hard to hear slow-moving vehicles from behind, even when they are close.

I've also had the experience of being in a shopping center parking lot, hearing a car drive up behind me, and before turning around knowing it was my wife, Cathy, because I recognized the distinctive sound of a Tesla Roadster. On the flip side, Cathy has noticed not being able to hear a nearby gas car in a parking lot because of the noise made by a much louder gas car an aisle or two over.

As a responsible driver, I don't depend on pedestrians hearing the roar of my engine so they can scramble out of my way before I mow them over. But the situation is more complex than just my personal experience.

In May of 2011, I participated in a meeting of the United Nations working group that is developing a proposal for an international standard for quiet vehicles. There I learned a great deal about the subject and was able to share my insights as an experienced electric vehicle driver.

The predominant sound made by cars moving above 15 to 20 miles per hour is tire noise. At slower speeds, it's engine idling, fans, and so forth. It's those lower speeds that are of concern.

Hybrid and electric vehicles aren't the only quiet vehicles on the road. Many modern sedans are also virtually silent at low speeds where tire noise is not significant. Therefore, the UN is taking a broader approach to this problem than the US Pedestrian Safety Enhancement Act of 2010, which only considers minimum noise levels for electric and hybrid vehicles.

The sound made by gas cars is actually quite poor for alerting pedestrians to nearby vehicle traffic. Most of the sound made by internal combustion vehicles is low-frequency, which humans have difficulty locating, and carries for long distances, adding to ambient noise levels that can mask out nearby vehicles.

For an artificial car sound to be effective, it has to be localizable and distinguishable as coming from a vehicle. So having an EV rumble like a muscle car or chirp like a bird is a terrible idea. Studies presented at the UN workgroup meeting show that the best sounds are broad spectrum sounds without low frequency content.

The issue is even more complex for blind pedestrians who develop skills in using their senses in ways that are completely outside the experience of the sighted public. The idling sounds made by stationary vehicles are useful not only for detecting the presence of nearby cars, but also for using them as positional markers. Consider walking across a wide, busy street and trying to stay in the crosswalk with your eyes closed. The sound of the idling cars nearest the crosswalk act as navigational beacons, keeping blind pedestrians from drifting out of the crosswalk and into traffic. For this reason, it's important to be able to hear a car in the street even if it is not moving.

It's also important to be able to judge the size of vehicles by their sound. Drivers behind a large, stopped vehicle can get impatient at the hold-up and decide to blast around the unwanted obstruction, only to find that there was a good reason for the large vehicle to be stopped: pedestrians in a crosswalk. For this reason, blind pedestrians may choose to avoid this risk by choosing not to cross when they hear a large vehicle at the head of the line.

As an EV driver, I appreciate the quiet ride of electric cars. The last thing I want is some obnoxious artificial sound added to my car. From what I learned at the working group meeting, a properly designed sound doesn't have to be overly loud, it can be effective even at a sound level that is below the ambient noise level. I believe we can add sound to quiet cars to increase pedestrian safety without compromising the advantage of electric cars in improved driving experience and reduced noise pollution, but doing so demands careful thought and consideration of many complex issues.

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.

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.

Tesla Motors was the first automaker to sell a production electric vehicle based on lithium ion batteries, the Tesla Roadster. Current Roadster owners as well as other prospective electric vehicle owners are interested to know how these batteries will hold up over time and miles.

It's still pretty early in the game. Tesla Motors tells us that we should expect to have our battery packs holding 70% of their original capacity after 5 years or 100,000 miles. The oldest Roadsters are a bit over three years old and some vehicles are getting up into the 30,000+ mile range.

How are the battery packs holding up so far? I've collected data from 20 owners in the Pacific Northwest to get an approximate idea of our batteries are performing.

Before we dive into the results, I should explain a bit about how battery capacity is instrumented on the Roadster. The Roadster has two primary charging modes. Standard mode charges up to about 90% of the pack's capacity and holds the bottom 10% of the capacity in reserve. Range mode fully charges the battery pack and shows the full range available, including the bottom 10%. The range is shown in two ways, "Ideal Range" and "Estimated Range." Estimated range states the range based on recent driving history and so can't be compared across vehicles. Ideal range shows how many miles you can drive in the current mode if driving with the same mixed city/highway average energy use that gave the Roadster its EPA -rated 245 mile single charge range. The corresponds, for example, to driving 55 to 60 mph on level freeway in moderate weather.

First, let's see how miles driven affects battery capacity.

The red squares at the top of the graph show the range mode capacity expressed in ideal range miles (aka ideal miles) versus miles driven on each battery pack. The blue diamonds show the standard mode range. The straight lines show the tread for each set of readings. I interpret this graph to show that for this set of vehicles, individual variation between cars is larger than the pack degradation over approximately 30,000 miles. For range mode, the variation between cars is as much as 15 ideal miles between cars with comparable mileage, while the linear trend shows a drop of only 5 ideal miles across 30,000 miles of driving. For standard mode, the variation between cars of comparable mileage is under 10 ideal miles while the trend line shows a drop of perhaps 6 ideal miles.

Lithium ion batteries lose capacity over time even if you don't use them. The graph shows the same vehicles over time instead of miles.

Again, we see the same apparent patterns: variation between vehicles is larger than the average range lost over three years and variation in range mode is larger than the variation standard mode.

While this is enough data to see some patterns emerge, it's a small fraction (about 1%) of the total Roadsters on the road. I'd like to collect more data to confirm these trends and also separate the effects of time and miles. Most of the Roadsters in this set are in the relatively mild coastal climate of Oregon, Washington and British Columbia. It would be interesting to analyze data from Roadsters in more extreme climates.

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.