Have Nissan Leafs in hot states suffered premature battery aging, or is the apparent loss in capacity down to a malfunction in the Leaf’s dashboard display? 

That’s been the question on the lips of Nissan Leaf owners worldwide after some owners in Phoenix, Arizona, began reporting that their cars had lost capacity bars

Earlier this month, Andy Palmer, executive vice president of Nissan reportedly dismissed reports of early battery capacity loss as a faulty battery level display, but now an independent investigation, led by Leaf enthusiasts, has concluded that Leafs with lost dashboard capacity bars do indeed have a smaller range than when they were new. 

The test, organized by Leaf owner and electric car advocate Tony Williams, took place over the past weekend in Phoenix, Arizona. 

Using twelve different Nissan Leafs with varying amounts of battery capacity bar loss, Williams and his team of volunteers meticulously recorded each car’s state of charge versus distance travelled on a pre-planned route, using the popular third-party GID state of charge meter for added accuracy. 

In order to eliminate as much noise from the data as possible, each driver was given a set of strict test conditions to follow, including no use of air conditioning, and traveling at a pre-set speed where possible. 

Since the test ended on Saturday, Williams has been carefully collating the data from the test. 

2012 Nissan Leaf 4-door HB SL Headlight

2012 Nissan Leaf 4-door HB SL Headlight

The results show a clear loss of range in line with indicated battery capacity loss.

Moreover, some of the Leafs used in the test exhibited battery capacity loss after two years far greater than Nissan's own five and ten year battery capacity estimates predicted. 

For Leafs with 11 capacity bars showing instead of the full 12 capacity bars, indicating approximately 15 percent loss in battery capacity since new, ranges of between 73 and 80 miles were recorded, in keeping with the EPA’s official range estimate for the car.

For the six Leafs with 10 capacity bars showing, an average range  from full to empty was recorded of just under 72 miles per charge.

The worst affected Leaf, with four capacity bars missing, or around 60-65 percent of its original battery capacity remaining, was only capable of driving 59 miles before running out of charge.

Those Leafs examined with lost capacity weren’t all older, 2011 models either. 

“One woman, who just bought the car a month ago, couldn’t come close to 100 percent capacity,” Williams said. “When fully charged, her car was in reality only holding 91 percent of its original ‘new’ capacity.”

Speaking to Williams earlier on, we were told that despite some extensive searching, the team could not find a single Nissan Leaf in Phoenix which had its original battery capacity intact. 

And that included brand new 2012 Leafs sitting on dealer lots. 

The test results certainly vindicate those with lost capacity bars who had insisted their cars were suffering from premature battery aging, but without intervention from Nissan, it will do nothing to calm the fears of Leaf owners in hot climates who have yet to experience any battery capacity loss. 

At the time of writing, Nissan has not formally commented on this test.

A faulty battery gauge or premature battery aging caused by extreme heat? 

Let us know your thoughts in the Comments below.


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