SparkE wrote:It doesn't matter if it is 'normal' or not. It's what you have. Don't agonize over it.
And Li-Ion batteries do 'age' (lose capacity as the get older) - add on losses due to usage.
Is it normal to go from 17.1 to 15.6 in 3 months is the question? I guess i will get a new battery if i lose 1.5 every 3 months.
Do you know what your capacity was last Dec? What is the difference in temp where you are living between Sept and now?
Cold months you will get your lowest readings. Warmer months see your best numbers.
It is possible to see a large decline due to temp alone. I have had years with a 1+ drop from summer to winter with most of it recovered the next summer.
I am tending to agree with you. In June 18 my 2014 Spark EV battery capacity was 17.2 kWh. On Dec 31 it had dropped to 16.5 kWh. My 2016 Spark EV battery capacity dropped from 16.6 kWh in June to 16.1 on Dec 31. Ambient temperatures in June were around 90 - 100 deg. F. This morning, Jan 1, 2019, the low was 33 deg. F. I expect, as you indicated, the capacity values will gradually go back up as the ambient temperature increases. I will continue to measure the battery capacity in both cars to see if this is true. I am using TorquePro running on an Android tablet and an OBDLink MX bluetooth adapter to make all measurements.