Siry: Nissan Leaf Has No Active Thermal Management, "Overpromises" Range Numbers

Edward Niedermeyer
by Edward Niedermeyer
siry nissan leaf has no active thermal management overpromises range numbers

Former Tesla PR man Daryl Siry’s Autopia columns are always good for some interesting insights on the EV world… as long as you take them with the grain of salt that Siry’s status as “advisor” to EV startup Coda Automotive demands. This week Siry has it in for the mass-market EV frontrunner, the Nissan Leaf, accusing its makers of “cutting corners” and “overpromising” range specs. According to Siry:

First, Nissan overpromised on the realistic range by consistently quoting a number tied to the most optimistic benchmark, the LA4 cycle. Drivers who stick to stop and go traffic on city streets in temperate climates may indeed consistently see 100 miles of range, but most drivers will see significantly less in a mix of city and highway driving. Driving in California, the country’s top market for electric vehicles, involves a lot of time on highways where the 65 mph speed limit is rarely observed. The LA4 cycle Nissan quotes mostly stay below 30 mph with one two-minute “sprint” at 55 mph every 22 minute cycle.

But wait, there’s more!

It also appears Nissan has cut corners on the most critical aspect of electric vehicle technology – the battery pack. The key engineering tradeoff Nissan has made is opting not to include active thermal management, where the temperature of the pack is controlled by an HVAC system similar to what cools the passenger cabin on a hot day. Instead, Nissan has opted to use only an internal fan that circulates the air within the sealed pack to evenly distribute the heat, which escapes by passive radiation through the pack’s external case.

Oh snap! Siry quotes Nissan’s US product planning boss Mark Perry’s defense of the decision thusly:We don’t need thermal management for the U.S., but we are looking at the technology for Dubai and other locations like that… We’ve gone on the record saying that the pack has a 70-80 percent capacity after 10 years… If it wasn’t our pack and it wasn’t our engineers and we weren’t working on it for 17 years… we wouldn’t make the statementIn a fascinating twist, Paul Hawson, a Nissan product planner who worked on the Leaf tells Siry the active thermal management was left off so the Leaf could be a true five-seater. Otherwise, the thermal management gear would split the rear seats, forcing an awkward two-bucket configuration like that of the Chevy Volt.But, as Siry points out, it gets pretty hot in Pheonix, Arizona, one of the Leaf’s US launch markets. If Dubai is a concern for Carlos Ghosn’s EV boffins, the American southwest probably should be as well. We’ll bet a nomex suit that Nissan has thought this through, and Siry’s just sniping at Coda’s main competitor… but if Leafs start exploding in warmer locales, Nissan’s gamble on EVs will have been yet another auto industry lesson on the dangers of hubris.
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  • R H R H on Jan 26, 2010

    I really think "EV's" are much more practical in the motorcycle world: $7-$10k for a bike vs $40k+ for a car A LOT less emissions from an electric motorcycle vs std motorcycle, as opposed to comparing an electric car vs a standard car. People don't expect to take cross country trips on dual sport or basic street bikes (I don't know of any touring electric bikes) or scooters. People expect to be able to do this in a car. People on a bike don't expect heat/ac on a bike, where they do in a car. People don't expect large cargo space on a bike -- they prefer it in a car. The only downside is that electric bikes have very short range on the highway currently (20 miles). For urban commuting you are talking 40-100 miles currently.

    • See 1 previous
    • R H R H on Jan 27, 2010

      Pretty much EVERYTHING gets squashed by an 18 wheeler. That is not specific to motorcycles. I also think you missed my point completely: 1) motorcycles in general produce much/many more bad emissions than cars (since most IIRC don't even have cats. I know here in IL there is no emissions testing for motorcycles). The amount of pollution saved PER unit on an electric motorcycle vs a conventional one should be much greater than an electric cars vs a standard car. On top of pollution to actually create & dispose of the battery (since there are less batteries) used for a bike should be less than that of a car. Zero Motorcycles says their battery is so safe you can actually eat if you want to. 2) The "price premium" for an electric bike is not higher (in raw, not in %) than a standard bike. There are several companies with products that you can purchase right (& register) right now that are street legal. Prices are low as $8k for entry level. People already pay more than that for a 600cc sport bike, harley, goldwings, or midsize cruisers. I'm not arguing cars vs motorcycles for safety. I'm arguing that electric motorcycle vs conventional motorcycle makes more sense (emissions & price-wise) as opposed to std car vs electric car. It doesn't make sense purely from a "I-need-to-save-gas-$" perspective since most motorcycles are 40-50+mpg already.

  • Blowfish Blowfish on Jan 26, 2010

    Montreal? This time of year in Montreal the normal temperatures are a high of -6C(21F), and a low of -15C(5F). How well will your batteries work if the car is on the street and the weather is like that? Most part of Canuckstan has this kind of similar weather, At -15 c wonder how many 7-11s can u pass before u make it to work, I bet u do need a plug in at work just like most Parking facilities in Winnpieg , Regina etc. But these parkings were only supplying u enough current of 100 - 200 watts block heater. 1 EV charging will = to a dozen of regular cars block heater consumption. The Equation of consumption will get upset pretty quick! What would u do when u run out of Juice in a EV on the autobahn? EVs are like bicycling, one cannot push it when high on energy or else u will have to gimp home painfully.

  • Master Baiter "...but the driver must be ready to step in and take control. The system is authorized for use during the day but at speeds lower than 40 mph..."Translation: It's basically useless, and likely more stressful than piloting the car ones's self.
  • Alan My friend has a Toyota Kluger (made in 'murica). A Highlander. These things are based on a Camry platform. I have driven the Kluger we had at work and I find them quite boring even for a SUV. An appliance. I hope this will deliver some driving pleasure. I found the Camry a better boring vehicle.
  • Alan Most Lexii look good to reasonable.....................until you see the front ends with their awkward grilles. It actually would look normal on a GWM, LDV or any other Chinese vehicle.
  • Tassos These last months, every day seems to be another great, consequential piece of news for Tesla, who does not just DOMINATE, it OWNS the US and FREE WORLD BEV market.It is the ONLY (repeat ONLY) maker that builds its huge best sellers at a PROFIT, ie, SUSTAINABLY. FOrd EV is bleeding 3 billion in losses. GM hides theirs, and I bet they are even HIGHER. VW has spent a huge no of billions and its ID series has been an UTTER FAILURE.Toyota, already 12 years too late, is yet to try. I doubt they will succeed to dethrone TESLA.
  • Tassos Again: I never took VOlvo seriously in the last 20 or so years.Chinese Volvo-Geely has a dizzying number of models, I have lost count how many,YET its sales and market share in the US has always been DISMAL these last 20 years.It ranges from a pathetic 0.5% to 0.8% of the US market.For comparison, Toyota has 15% and GM has even more. Tesla has almost 10 TIMES VOlvo's share, with a PITTANCE of really TWO Models, the 3 and the Y, as the S and the X hardly sell any copies any more.So why do we keep reading articles about Stupid VOlvo?Because they have the best PR department of any maker.