Nissan responds to Leaf owners' massive test in battery aging case
The controversy over Nissan Leaf battery pack capacity loss is getting deeper, following a statement from Nissan published through Green Car Reports, and a response published by EV Owner Tony Williams writing on InsideEV's. Nissan's response that range loss is occurring for Leaf's that have been driven a long distance, but Williams counters with evidence that contradicts Nissan's claims.
As TorqueNews noted earlier, a group of Phoenix-are Nissan Leaf owners staged a test last weekend to verify claims of battery pack capacity loss. This lost capacity would result in a shorter driving range than Nissan claims for the Leaf, and if true would make the Leaf a less-useful car. The issue has been under discussion on the MyNissanLeaf forum for months, leading Nissan to issue a statement saying they were studying the issue.
In July, Nissan brought seven Leaf's to its technical unit at its Arizona Testing Center for a technical assessment. Nissan collects data from each Nissan Leaf and has found that the 450 Leaf's currently in Arizona are on a path which will result in 76% capacity after five years, rather than the 80% capacity Nissan had expected. Nissan's published claims of expected range loss over time were based on an average driving distance of 12,500 miles/year in climates similar to Los Angeles. The seven Leaf's examined closely by Nissan had all been driven much further than the average, some well over 20,000 miles/year.
To complicate this, Nissan additionally says the geographic layout of Phoenix makes the problem worse. Driving at highway speeds requires more energy, and is harder on the pack, than is driving at city street speeds. Because Phoenix is a sprawling city where highway speed travel is more common than city speed travel, Leaf's in that city have a harder life than those in other cities, according to Nissan. The argument is rather technical, but battery pack life is actually not measured in its calendar age, but based on the total usage the pack has seen (kilowatt-hour throughput). With a full charge a Leaf driven at highway speed might travel as few as 50 miles, but driven at city streets speed could travel as far as 100 miles.
Nissan's Mark Perry told Green Car Reports, ”The cars and the battery packs are behaving as we expected”. This may be little comfort to the affected Nissan Leaf owners because Nissan had published certain claims about range, and range loss over time.
Indeed, an article on InsideEV's responding to Nissan's statements in the Green Car Reports article characterized those statements as their "latest excuse."