Showing posts with label 2011 Nissan Leaf. Show all posts
Showing posts with label 2011 Nissan Leaf. Show all posts

Monday, May 31, 2010

Details on Nissan Leaf battery pack, including how recharging speed affects battery life

Interesting....
Nissan broke ground on a new battery plant in Smyrna, Tennessee yesterday (figuratively, anyway, the actual bulldozing doesn't start for a few weeks). For now, we will call this the U.S. Leaf battery plant, but it's really part of Nissan's strategy to electrify more and more of its vehicles. As we mentioned yesterday, once it is up and running at the end of 2012, the plant will have the capacity to make 200,000 battery packs a year. The nearby vehicle assembly facility where the U.S.-built Leafs will come to life will have a maximum capacity to make 150,000 Leafs a year alongside other Nissan vehicles like the Altima and Pathfinder. The extra capacity, if used, could be sold to other automakers or go into non-Leaf Nissan products.

In Smyrna yesterday, Nissan's director of product planning, Mark Perry, gave AutoblogGreen some more information on the Leaf battery pack. As we know, Nissan says the 24 kWh pack gives the Leaf a 100-mile range on the gentle LA4 cycle (meaning it probably isn't a totally reliable guide to estimate real-world driving). Still, this means the test packs have been charged and discharged a lot, because Perry said Nissan has done "hundreds of thousands" of miles of reliability testing on the battery packs, including dunking them in a pool and freezing them. Not that we'd expect him to say anything different, but Perry is confident that the battery pack is totally safe.

What's in the pack? 48 modules, each with four cells (so, 192 cells total) arranged in a big square. The part that sits under the real seat is a little taller than the rest, as the modules are stacked vertically while the other modules lay horizontal under the front seats and floor. The entire pack weighs around 600 pounds and contains around 9 pounds of lithium. How will people use the Leaf? Find out Nissan's expectations after the jump.

Once out in the real world, Nissan expects most Leaf charging to be done using Level 2 (240V) units, because that's what most people will get at home and what will be used in public chargers. Level 2 chargers can get the pack from zero to 100 percent in about eight hours. Level 3/direct quick charging could happen, but it's not widely available yet. Meanwhile, Level 1, aka recharging from a standard 110V outlet, will be "more for emergencies," Perry said. It'll also take ages (think 20+ hours).

How you recharge the pack will affect its life. Nissan has said it expects to Leaf drivers to have around 70 to 80 percent capacity left in the pack after ten years. What will get drivers to the upper or lower end of that range? The amount of fast charging one does. With regular Level 2 charging, drivers should expect 80 percent live left in the battery. With a lot of Level 3 charging – two or three times a day – the pack will only be at the 70 percent level. Level 3 charging is appealing because it can get the battery from zero to 80 percent full in under 30 minutes, but there is a very clear drawback if it becomes a habit. Perry said that most people will be happy with 240V home charging:

The people who drive EVs today, they talk about charging like this: "Charging to me is five seconds. I plug it in, I walk away and forget about it." To them, it's really pretty simple.

What might be coming down the road? Perry said there is no Moore's law in battery production, but did say Nissan is seeing about an eight percent improvement in things like cost reduction, range and efficiency, year over year. Whether this results in cheaper packs or lighter/smaller/better ones will depend on what the early adopters do with their Leafs and what they tell Nissan they want. What's your preference?

PRESS RELEASE
Type: Laminated lithium-ion battery
Total capacity (kWh): 24
Power output (kW): Over 90
Number of modules: 48
Battery pack contents:
-Positive electrodes
– Lithium manganate-Negative electrodes
– Carbon-Cells-Modules-Assembly parts
Charging times:
-Quick charger DC50kW (0 to 80%): apx. 30 min
-Home-use AC240V charging dock (0-100%): less than 8 hrs
Battery layout: Under seat & floor
Battery life: After 10 years, the battery is expected to have 70-80 percent of its original storage capacity.

Source;
http://green.autoblog.com/2010/05/27/details-on-nissan-leaf-battery-pack-including-how-recharging-sp/

Tuesday, May 4, 2010

2011 Nissan Leaf First Drive

I am interested to see how this does, it looks like a great start in the 'alternative fuel' race....
If Fortune Favors the Brave, This Car Deserves To Succeed
Given that there has been so much talk and so many wise words from so many different directions about our all-electric future, it can almost go unnoticed that the one thing no one has actually gotten around to doing is translating a single syllable into something a normal family with a normal budget can go out and buy.

Until now.

The 2011 Nissan Leaf is not a low-volume slice of automotive exotica like a Tesla Roadster, nor is it an electrified version of a conventional gasoline car like the Mitsubishi i MiEV, and it is certainly not a plug-in hybrid like a Chevrolet Volt or a conventional hybrid like a Toyota Prius. The 2011 Nissan Leaf is a brand-new, purpose-built, mass-produced, battery-powered family car and, as such, the very first of its kind in the world. And we've driven it.
But is it a real car for real people?

You Say You Want a Revolution
The moment of truth is upon us. We're in the East End of London in a large concrete parking lot upon which Nissan has marked out a track for us to sample the 2011 Nissan Leaf. Actually, two Leafs are here today. One is for static assessment, and it cannot be driven. The car that can be driven is a late-series prototype, and this one wears the body of a Nissan Tiida, known as the Versa in the U.S. Underneath the bodywork, however, this car is pure Leaf. It is very like the car that John O'Dell, editor of Edmunds.com's Green Car Advisor, drove last summer.

Before you even slot the shift lever into Drive and tentatively press the throttle, the 2011 Nissan Leaf has done much to win you over. For a start, there's no reason not to have one — in design terms, anyway.

This is a full five-seater with a conspicuously large trunk. You sit a little higher than you might expect because there are 48 lithium-ion battery modules under the floor, but that's no bad thing. The cabin is spacious, airy and promising. The electronic dashboard works particularly well, using state-of-the-art graphics to present almost certainly more information than you will ever need, a way to reassure you that the Leaf is not going to run out of electrons without giving fair warning first. Nissan calls this "range anxiety" and, as we shall see, it's an understandable affliction.
At first, the Leaf is entirely as expected. Once you're satisfied the Leaf is actually awake, you select Drive. Then one small squeeze of the throttle later, you're under way. It's not silent, not quite at least, but even in the unlikely event that your everyday steer is a Rolls-Royce Phantom, you're going to be stunned by the Leaf's smoothness and refinement.

The Fun-To-Drive Quotient
You ease the Leaf through the first corner and see a long straightaway appear, so naturally you nail the throttle to the floor, expecting acceleration of the barely discernible variety. But that's not what you get.

Because maximum torque is always and instantly available, the Leaf jumps forward with sufficient alacrity to make you wonder if it should not be renamed "Leap," a word that describes both its throttle response and game-changing technology with equal precision. Nissan reckons this electric vehicle's midrange punch is on a par with a sedan powered by a 2.5-liter V6 (probably it really means a Nissan Altima 2.5 with its inline-4, but whatever), and we'd not argue with that.

The 2011 Nissan Leaf also has a party piece, a feature quite incidental to the reason it exists but likely to add considerably to its appeal. And that is the location of the batteries under the middle of the car instead of in the trunk. Because the Leaf represents a clean-sheet design, Nissan created a platform that centralizes the weight of its heaviest components — the batteries — within the span of the wheelbase. And this bit of physics when combined with a very low center of gravity makes the Leaf very responsive to directional changes.

That is to say, all this makes the Leaf implausibly good fun to drive. OK, this is no Porsche Cayman, but when your expectations on the dynamic front are precisely zero, anything comes as a pleasant surprise, so the Leaf's ability to corner both flat and fast adds up to considerably more.

Reality Bites
And now we must let the cold light of day flood into this rosy picture. Because while the Nissan Leaf might be surprisingly good to drive, what matters — and what, ultimately, will determine its success or failure — is what it is like to live with.
The bottom line is that currently the 2011 Nissan Leaf has a range of just 100 miles, and that's worked out to the U.S. LA-4 driving cycle (the original EPA city driving cycle, before the current FTP cycle was instituted), and this means that even Nissan admits that the car's owners are going to struggle to achieve it. Moreover, the Leaf will top 90 mph, but it won't travel 100 miles at that sort of speed — 60 miles is more like it, we're told. So this confirms what we all know about electric cars, which is that they are meant for city streets, not interstate freeways.
It's also useful to remember that it takes eight hours to recharge a Leaf with an industrial-type 220-volt hookup, though you can get an 80 percent recharge in 30 minutes from a specialized high-energy recharge station.

The math still adds up for most people, since we live in cities. And, as we're constantly reminded, 80 percent of us cover less than 60 miles daily. So Nissan considers the Leaf to be an eminently viable proposition as a result.

Besides, the Leaf also does much to minimize any residual range anxiety that you might have. Its navigation system is hooked up to a global database, so as the charging infrastructure expands, the nav will automatically update and always be ready to take you to the nearest power supply. Over and above that, the car's operational radius is displayed on the nav screen, so if you program a destination that's beyond the circumference, the nav will not be shy about letting you know.
You can even talk to the 2011 Nissan Leaf through your mobile phone, telling it, for instance, to warm up its interior on a cold morning while it's still parked and charging in your garage, saving you battery life and a cold backside. Once it's charged, it will send you a text saying it's hot to trot.

The Cost of Being Green
Of course what you pay for the electricity and how clean it really is depends on prices that change and the kind of power station in which the electricity was generated, but it's still safe to say that the Nissan Leaf's cost per mile traveled is a small fraction of what it would be for a car of the same size that burns gasoline.

But there's another saving, too. Where a conventional car needs an annual checkup, the Nissan Leaf effectively looks after itself. In fact, Nissan says the only routine maintenance required at the dealer will be the renewal of brake pads, and since the Leaf's regenerative braking system minimizes pad wear, it could be some years before the car needs any maintenance at all.
In around five years, however, the Leaf's lithium-ion batteries will only take around 80 percent of their original charge, so you might feel inclined to change them, not least because the replacements will almost certainly have far greater range than the old ones even when they were new. Indeed Nissan says it has targeted a cruising range of 300-350 miles for the Leaf, though the company admits the technology that will achieve it does not currently exist.

Will This Car Succeed?It's the million-dollar question — or multibillion-dollar question, if you're Nissan. Certainly the 2011 Nissan Leaf will prove an outstandingly able device for delivering urban mobility. The immediacy of its motor response coupled with its unforeseen dynamic nimbleness will make light work of heavy traffic and there really is very little for the range-anxious to fear so long as you remember to put the plug in the wall at night.

But as with other EVs we've driven, the 2011 Nissan Leaf will have to wait for the rest of the world to catch up with it. Only when it's possible to recharge your Leaf with another hundred miles of power in the time it takes to knock back a coffee will this car's true potential be unleashed. And only when batteries are capable of sustaining the Leaf for more than 300 miles or more will this and other EVs stand a chance of prevailing over the conventional automobile with an internal-combustion engine that has served us so well and for so long.

Don't hold your breath waiting for that to happen, though. Even in 2050, up to half the cars on our roads will still be powered by internal-combustion engines, Nissan says. So while the 2011 Nissan Leaf is undoubtedly the start of something big, it seems the finish is so far away that few of us reading this today will even be here to see it.
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