The pros and cons of buying a used EV
Despite all the headlines generated by the big players in the electric vehicle market, for the vast majority of New Zealanders making the dive into electric propulsion, buying a used EV is the only realistic option.
That isn’t just a bold claim – the numbers back it up rather conclusively. In a total car market (new and used) of around 300,000 annually, we have the grand total of 7233 electric vehicles (including plug-in hybrids) registered on NZ roads at the time of writing.
That is undoubtedly a tiny number, regardless of how quickly it is growing, but even smaller is the percentage of new vehicles that make up that number.
More than 3250 of those total EV registrations are for the pureelectric Nissan Leaf, a vehicle only sold new here briefly and in relatively small numbers. So the majority of those 7233 EVs on our roads are second-hand imports; most of those imports are the little Nissan.
Typical dealer prices we have found: a 2011 model with 68,000km for $11,000, a 2013 with 35,000km for $20,000 and a 2016 version with 12,000km for $28,000. So the Leaf really is a relatively affordable EV for Kiwis.
But is buying a secondhand electric vehicle (which really means a Leaf in NZ, according to the numbers) a risky purchase?
Specifically, what about those horror stories of EV batteries wearing out after just a few years, at a potential replacement cost of around $9000?
Like any car, the condition of a used EV will depend on how previous owners have treated it.
Like a conventional internal combustion engine, the battery pack in an EV will lose power and efficiency over time, the speed of which depends largely on how it has been driven and charged.
A recent Lambert study of the degradation of batteries in the Tesla Model S (also published on EECA’s website) found that drivers who used the performance of their cars regularly and drove ‘‘very hard’’ on a daily basis experienced faster battery degradation than those who didn’t. But the study still projected that, even then, most would still have more than 90 per cent battery capacity remaining after 200,000km.
Which is nice if you can afford a Tesla.
With their large battery packs, Teslas generally go through fewer charging cycles than other EVs with lesser range, which minimises the degradation.
Regardless, if your potential used EV purchase has been driven hard, then its battery won’t be in the same shape as one that has been driven carefully – in the same way that a roundly thrashed internal combustion engine will be a few kilowatts down on a more considerately driven equivalent after a decade or so.
The same general ‘‘fast is bad, slow is good’’ thing applies to charging: while fast charging is convenient, slower charging is better for the battery and while most manufacturers regulate how the battery charges to maximise battery life, a car that has spent its life on fast chargers will suffer in terms of battery health.
An Energywise NZ case study into EV batteries recommends that batteries not be charged to full capacity every day, nor should they be run down too far, with a state of charge of around 60 per cent being the best to maintain on a regular basis for maximum battery health and longevity.
But because mass-produced EVs are still a relatively new thing in today’s motoring world (despite the concept being around as long as the car itself has), there are still a few potentially unseen pitfalls that could be lurking.
A recent study by local researchers and EV enthusiasts discovered that the newer 30kWh (launched in 2016) Nissan Leaf’s battery appeared to be degrading at a faster rate than the older 24kWh car (released in 2010).
Flip the Fleet reported that crowdsourced data from Leaf owners around the country who have registered their cars with www.flipthefleet.org and shared data taken from their battery management systems showed that the batteries in the 30kWh cars were degrading at around three times the rate of the 24kWh variant at two years of age.
While Nissan has never sold the 30kWh Leaf new in NZ (and only offers warranty cover on cars it has sold new locally, as is largely standard across the industry), the company offers a battery replacement warranty overseas, where there is a loss of four bars on the dashboard (equivalent to about 60 to 65 per cent battery capacity) within eight years or 160,000km.
This means that if the 30kWh cars continue to degrade at the rate that the Flip the Fleet data shows so far, the threshold for warranty replacement would be met in less than four years.
However, on the other side of this equation, the 24kWh cars would remain well inside this criteria, meaning that – much like ICE cars – one single model can throw up problems that others don’t have.
So is buying a used EV worth the risk?
As the popular Leaf shows, just like the traditional combustion engined car, there are proven good models and potentially dodgy ones, and just like buying any used car, doing your research is important.
Batteries do degrade – some faster than others – but then engines also lose power and can fail completely over time as well.
With a replacement for a Nissan Leaf battery running at around $9000 fitted (it will vary depending on supplier), it is a more expensive potential problem than a reconditioned engine. But also one that has the potential to become far cheaper over time as battery refurbishment technology improves.
Buying an EV, either new or used, comes with some unique risks – and some equally unique rewards – but that is the challenge (and the thrill) for the early adopter.