That may be true for Tesla batteries as the article mentioned and there are some Spark EV drivers who have driven more than 75k miles and still have considerable battery capacity remaining. I am not one of those lucky ones. Charging to 70% might be one way to extend battery life. But, unlike a Tesla, charging a Spark EV to 70% could, depending how the car is used, seriously limit the usefulness of the car.JeremyWinter wrote: ↑Mon Jan 13, 2020 10:04 pmThat's not how battery degradation works. It peaks off after a initial substantial decline.
https://ww.electrek.co/2018/04/14/tesla ... data/#aprd
I have leased or owned a 2014, 2015 and 2016 Spark EV and every one has shown a significant drop in measured battery capacity. I also tested a friend's 2016 Spark EV and his battery capacity measured 14.8 kWh at just over 30k miles. In all 4 cases, there was a lot of 90%+ charging.
Having said all of this, there is evidence in my data to suggest I need to re-evaluate the 80% charge limit for a longer period of time.
Data for my 2014 Spark EV:
For the period 04 Apr 19 thru 12 June 19, I drove 953 miles (18766 - 17813) and initiated 20 charging sessions using my L1 EVSE with the car set to a 12 amp charging rate and a timed charging interval set to limit charging to 80-85% of SOC by manually disconnecting at 8 am each morning. The start and stop SOC value for this interval was 16.2 kWh. At this point I started charging to 100% and my SOC started dropping again. 15.9 kWh at 18841 miles; 15.7 kWh at 19896 miles, 15.6 kWh at 20788 miles, 15.5 kWh at 21039 miles, 15.4 kWh at 21424 miles and 15.3 kWh at 21862 miles on 6 Jan 2020.
My TorquePro data also shows:
953 miles between the first and last of the 16.2 kWh values (20 charging sessions limited to 80-85%).
1000 miles between the first and last of the 15.9 kWh values.
737 miles between the first and last of the 15.7 kWh values.
172 miles between the first and last of the 15.6 kWh values.
79 miles between 15.6 kWh and 15.5 kWh.
385 miles between 15.5 kWh and 15.4 kWh.
71 miles between 15.4 kWh and 15.3 kWh.
Bottom line: I am going to try again limiting charging to 80-85% and see what happens. Another interesting thing I saw in the data for my 2016 Spark EV was the measured battery capacity rose and fell in sync with the battery temperature at the time of measurement. Lower battery capacity usually occurred below 20 deg. C