Miles or time - biggest factor in battery degradation

[danev]

Looking at used Spark EVs that are starting to flood the market with mileage from 10,000 to 40,000 and wondering which is the greater factor in battery degradation -- mileage of age of battery.

Theoretical situation: Two twin brothers each own a spark Spark EV, each driven in same local city, and have similar driving habits.
Spark A is a 2015 and has been in service for 42 months and has 20, 0000 miles.
Spark B is a 2016 and has in service 30 months and has 30, 000 miles.
Which one is likely to have the least battery degradation and the most life left in its battery?

 

[SparkE]

Looking at used Spark EVs that are starting to flood the market with mileage from 10,000 to 40,000 and wondering which is the greater factor in battery degradation -- mileage of age of battery.

Theoretical situation: Two twin brothers each own a spark Spark EV, each driven in same local city, and have similar driving habits.
Spark A is a 2015 and has been in service for 42 months and has 20, 0000 miles.
Spark B is a 2016 and has in service 30 months and has 30, 000 miles.
Which one is likely to have the least battery degradation and the most life left in its battery?

Can't answer based on facts presented.

I think *how* (and how fully) the car was charged is more important than anything in your example. I think that the battery in a vehicle with 10K on the odometer that was charged to 100% every night in Phoenix, with temps over 100, will be in worse shape than a car with 30K miles that was rarely charged over 75% in Portland (temps rarely over 80).

I suggest getting an OBD reader, and Torque Pro, and measure the supposed capacity of the battery before purchase. (and then baby the battery afterwards)

 

[MrDRMorgan]

Looking at used Spark EVs that are starting to flood the market with mileage from 10,000 to 40,000 and wondering which is the greater factor in battery degradation -- mileage of age of battery.

Theoretical situation: Two twin brothers each own a spark Spark EV, each driven in same local city, and have similar driving habits.
Spark A is a 2015 and has been in service for 42 months and has 20, 0000 miles.
Spark B is a 2016 and has in service 30 months and has 30, 000 miles.
Which one is likely to have the least battery degradation and the most life left in its battery?

Given below are a some data points for you to consider. All data was taken using TorquePro running on a Nexus 7 android tablet and an OBDLink MX Bluetooth adapter.

1. 2014 Spark EV 2LT w/o DCFC - all charging done at home using the L1 EVSE that came with the car and with the car set to a 12 amp charging rate.
Data for 73 charging sessions:
10 June 2018 - 14,144 miles - BC 17.2 kWh.
24 Aug 2019 - 19, 808 miles - BC 15.9 kWh

2. 2016 Spark EV 2LT with DCFC - mixed charging using about 2 DCFC sessions per week and the rest using L2 EVSE at home.
Data for 79 charging sessions - battery capacity data for DCFC charging sessions was not recorded. This data is for L2 charging at my home.
10 June 2018 - 10,284 miles - BC 16.6 kWh
24 Aug 2019 - 23,463 miles - BC 15.6 kWh

Note: Measured battery capacity graph for both cars has been reasonably flat since April of this year.

 

[Sam12345]

Just bought a car with 51k a 2015 I have no idea how it was charged was in San Diego area away from beach so hot desert temps. It has 14kwh to a full charge