Siry: Nissan Leaf Has No Active Thermal Management, "Overpromises" Range Numbers
Former Tesla PR man Daryl Siry’s Wired.com 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.
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.
More by Edward Niedermeyer
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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.
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.