A study carried out in March revealed that the larger 30 kWh Nissan leaf battery pack had a higher rate of battery degradation than the 24 kWh.
The study involved 283 Nissan Leafs, in which 82 of them operated on the 30 kWh battery packs. According to the findings, in a group of five cars with the larger battery pack, four of them showed a degradation rate of three times faster than the 24 kWh pack.
Good news to the leaf owners is that Nissan has announced a software update that would reduce the abnormal cell capacity loss.
On a report that was initially published by the clean fleet report, the update will fix the battery controllers, from which the problem seems to originate.
The report notes that the accelerated power loss was caused by a known problem of the battery controllers miscalculating the available battery charge and the remaining car range, an issue that the software update is expected to fix.
Initially, some of the leaf model owners thought that the different cooling system of the battery pack, in which the car uses air instead of liquid was the cause of the degradation.
It’s important to note that it’s the passive air cooling system that made the Nissan leaf models way cheaper than other EVs, making it the most sold electrical vehicle in history.
Over 300,000 units have been sold so far.
Nissan redesigned their battery pack chemistry in 2015, introducing a new system they called “lizard cell” that was said to be high-temperature resistant. High temperature is the primary cause of battery capacity degradation.
Those 2016/17 Nissan leaf owners who rushed to replace their battery packs with the newly redesigned versions reported the same issue of high rate of power loss. The redesigns were covered under the powertrain warranty by the company.
In 2018, Nissan started supplying refurbished battery packs in the Japanese market, at a substantially lower price of $2800 than that of the redesigned version of the same.
U.S Nissan leaf owners are yet to know what’s in store for them, as Nissan hasn’t announced an update or a replacement for that market. American Leaf owners may be looking forward to replacing their 24 kWh battery packs with the larger version of 30 kWh.
The March report didn’t touch on the 40 kWh battery packs.