Just over four years ago, a shiny red 2011 Nissan LEAF joined the Transport Evolved Staff car fleet as the Gordon-Bloomfield family’s daily driver. It quickly became known as Hiro Nakamura: a quirky, slightly nerdy but endearing little car that wants to save the world (and maybe the Cheerleader too).
Since then, just like the rest of our extensive staff car fleet, we’ve kept you up to date with various milestones along the way, including Hiro’s first MOT test and three-year service, the loss of Hiro’s first capacity bar at 52,800 miles, the loss of Hiro’s first capacity bar at 52,800 miles, and of course our fun, if somewhat misguided adventures in Europe last spring.
Over the past winter however, we’ve certainly started to notice a drop in battery pack capacity and range in our aging plug-in and on Sunday, the inevitable happened: Hiro lost his second capacity bar. This indicates our main staff Nissan LEAF can now store less than 80 percent of the energy it could when new.
For those who don’t know, all Nissan electric vehicles are built with not only a battery state-of-charge meter and range prediction meter — which many LEAF owners have taken to calling the ‘Guess-o-meter’ after its notorious inaccuracy — but also a capacity gauge.
Sitting to the right of the state of charge gauge, the capacity gauge records the overall amount of energy the car is capable of storing in its battery pack over time. When the car is new, the capacity gauge — a twelve-segment display — shows all twelve segments illuminated, illustrating that the new battery pack can store its rated capacity in kilowatt-hours of electricity.
As the battery slowly ages, the pack losses its ability to store as much charge as it once did, slowly reducing the pack’s overall useable capacity, something TransportEvolved regular and CrossChasm Technologies CEO and battery guru Matt Stevens explains very well below.
While most electric cars don’t display that capacity loss on the dashboard, Nissan’s LEAF and e-NV200 electric vehicles do by slowly extinguishing the twelve-bar capacity gauge as the battery loses its ability to store energy.
Back to our staff car. With 73,100 miles on the clock or thereabouts, we noticed the second capacity bar had vanished while waiting for Hiro to quick charge during a long, 500-mile weekend round trip. With a strong headwind gusting to beyond 20 mph in places, we’d also been hammering Hiro‘s battery pack pretty hard, driving just 45 miles at 70 mph before needing a top-up charge.
But don’t think that range is representative. A few days earlier, we’d managed more than 74 miles on a 90 percent quick charge, with just a half-hour, 3-kilowatt top up mid-way and ten miles remaining on arrival at our destination.
On a good day, we’re now resigned to a useable single-charge range of between 55 and 65 miles, with 70 possible with care. More is possible in optimum conditions, but now the pack degradation has started to impact longer-distance trips in the form of a little longer spent charging.
Interestingly however, it’s not the range impact that we’re feeling so much as the time to charge at a rapid CHAdeMO charging station. When Hiro was new, charging from empty to 80 percent full was possible in around 30 minutes. Now, thanks to increased internal resistance in the battery pack, charging from empty to 80 percent full can take nearer to 40 minutes.
That’s because as the battery ages, its ability to receive high current charging slowly drops. When charging at a compatible DC CHAdeMO quick charging station, the battery temperature rises more quickly than it once did. To protect the car and its battery pack, the LEAF’s on-board power electronics turn down the power output of the charging station earlier than it did when the battery pack was newer.
As for range anxiety? With more DC quick charging stations than ever before — at least twenty within easy reach of the Transport Evolved office and at least one DC quick charging station at every motorway service station on the M4 arterial motorway between Bristol and London, range anxiety is still a rarity. Provided we allow extra time, trips are still possible with relative ease, and only the occasional weather-related problem (like the aforementioned headwind) causes us to worry. Furthermore, hypermiling and switching into the Leaf’s ‘eco’ mode can extend range with care.
We note too that with the warming weather comes an increase in range, since less energy is being used to heat the interior and the battery’s internal resistance — which affects how much power you can put in and take out of a battery pack — naturally drops as the weather warms.
With front tyres now getting within a few thousand miles of their legal limits, our next big spend will be a new set of Michelin Energy Saver tyres and perhaps a full valet. And while we’ve not been able to get our car to talk to the LEAFSpy app lately, the arrival of two MyEV data loggers means that we’re already logging battery and usage data to document the longevity of our LEAF’s battery pack further.
As for warranty? In the UK, the LEAF’s standard battery capacity loss warranty is for 60,000 miles or five years, whichever is soonest, and covers capacity loss of four bars or greater. With 13,000 more miles beyond the warranty, that’s something long gone for us, and well within the planned behavior for a LEAF battery pack. Other cars in the UK have fared much better, with some on far higher mileage with less capacity loss.
Finally, we’d like to note that while we have lost some range since the car was new, we’re still happy with out 2011 Nissan LEAF overall. With no major faults since our last report and the odometer climbing ever-higher, we’re confident in the LEAF’s ability to keep serving as the main family transport until a planned move this summer means we’ll likely be passing Hiro on to new owners.
Until then, we’ll keep you abreast of the ownership experience of this and the rest of our fleet.
The Gordon-Bloomfield family paid full sticker price for the Nissan LEAF in 2011, and the car is owned and registered as a private vehicle.
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