SparkE
Posts: 326
Joined: Tue Sep 06, 2016 1:18 am
Location: SF Bay Area (San Jose, CA)

GOM (estimated mileage) and battery degradation

Wed Sep 11, 2019 1:03 pm

Visited a friend recently, he plugged me in to his company's L2 network while we ate lunch (a *very* long lunch) and went to 'full' for the first time in .... 4 months? Temp was around 78 degrees, and I was very happy to see that my 2015 Spark EV had a full range of ... 106 miles. Yes, it's based on driving habits and temp, however my original 2016 (the one my wife totaled) almost never got over 110, so I am very happy. The car is over 4 years old and still has most of its battery capacity. I think it is because *I* don't charge to full very often (generally between 75-80%).

DrMorgan, have your experiments on 'not charging to full' revealed less battery capacity loss, or is the battery degradation still fairly linear on your two?

MrDRMorgan
Posts: 977
Joined: Wed Oct 30, 2013 7:27 am
Location: Manteca, California

Re: GOM (estimated mileage) and battery degradation

Thu Sep 12, 2019 1:31 pm

SparkE - Interesting results so far.

2014 Spark EV - 16.2 kWh at 17813 miles and 15.7 kWh at 20118 miles.
2016 Spark EV - 15.6 kWh at 17874 miles and 15.5 at 23926 miles. A lot of DCFC charging to 90% is included too.

This week both cars gave me a full-charge GOM of 92 miles.

SparkE
Posts: 326
Joined: Tue Sep 06, 2016 1:18 am
Location: SF Bay Area (San Jose, CA)

Re: GOM (estimated mileage) and battery degradation

Sat Sep 14, 2019 10:13 am

DrMorgan, you have been tracking the battery capacity of your vehicles for a while and (i think) even have posted details of battery degradation in your 2 sparks.

I remember that you posted a while ago that you would experiment on 'not charging to full' - have you done that and has it revealed less (or 'slower') battery capacity loss, or is the battery degradation still fairly linear on your two?

I realize that YOU living in the central valley (HOT!) and me living near San Jose (temperate, usually, but not THIS year for some bizarre reason - 104F yesterday!) that temperature can have an effect on battery longevity. When it's hot, I don't charge - I set an alarm and wake up early (sometimes 5 a.m.) to plug in the car when the battery pack has cooled. If I had a 'regular schedule', I'd just use "departure timing", set it to an hour or two *after* I planned on leaving, and plug it in all night and just unplug in the morning.

MrDRMorgan
Posts: 977
Joined: Wed Oct 30, 2013 7:27 am
Location: Manteca, California

Re: GOM (estimated mileage) and battery degradation

Sat Sep 14, 2019 3:00 pm

SparkE -

My 2014 Spark EV has been charged using delayed timing so I charge overnight using the L1 EVSE that came with the car. I set my target finish time so I will have 80% charge at 8 am. A few times I have let it go to 100%. At 17813 Miles on 4 April 19, my measured battery capacity was 16.2 kWh. At 20118 miles on 11 Sep 2019 my measured battery capacity was 15.7 kWh. I lost 0.5 kWh in about 2300 miles. The graph shows battery capacity stays linear for a while, drops by 0.1 kWh and continue flat for a while more and drops again.

My 2016 Spark EV has been charged using an L2 EVSE (3.3 kWh) and delayed timing. but, many times I needed 95%+ for a trip so I charged to 99%. In addition, I have had many DCFC sessions where I cut off at 92%. I lost 0.1 kWh in about 6100 miles.

Both cars currently give me a full-charge GOM value of 92-95 miles. The current battery capacity in the 2014 is 15.6 kWh and the 2016 is 15.5 kWh.

Lately, my garage temperature in the evening has been running about 95 deg. F and remains fairly warm overnight. I will continue tracking the battery capacity to see what effect cooling weather will have on the degradation rate for each vehicle.

RSC
Posts: 34
Joined: Thu Sep 20, 2018 5:45 am

Re: GOM (estimated mileage) and battery degradation

Sat Sep 14, 2019 7:23 pm

I started tracking my battery capacity (Torque Pro) on a monthly basis:

Date Mileage Capacity (kWh)
5/5/2019 18601 16.1
6/1/2019 18905 15.9
7/3/2019 19259 15.9
7/13/2019 19425 16.2
8/1/2019 19669 16.3
9/1/2019 19878 16.4

I haven't succeeded in using BBCode to format this as a table.

This is almost all L1 charging at 8 amps, maybe a couple of times at 12 amps and one L2 session to get the car home from the dealer (16K miles, September 2018). As you can see, I don't drive much. The car is plugged in almost all the time, set to Rate and Departure charging. On the PG&E EV-A plan, this is almost all at night. I'm retired, so the car doesn't sit in a parking lot for very long. Sometimes when I return from a drive on a hot day I'll charge Immediate for 5 or 10 minutes just so battery cooling will kick in (unplug, then plug back in within 10 seconds).

The GOM currently shows 72 miles. I don't have LRR tires and live on a hill, so I don't get much regen starting out from full.

There seems to be a recent upward trend in capacity. It will be interesting to see what the capacity is on Oct. 1.
Last edited by RSC on Sat Sep 14, 2019 7:44 pm, edited 1 time in total.
Ray
2015 Spark EV 1LT, DCFC

MrDRMorgan
Posts: 977
Joined: Wed Oct 30, 2013 7:27 am
Location: Manteca, California

Re: GOM (estimated mileage) and battery degradation

Sat Sep 14, 2019 7:27 pm

RSC wrote:
Sat Sep 14, 2019 7:23 pm
I started tracking my battery capacity (Torque Pro) on a monthly basis:

Date Mileage Capacity (kWh)
5/5/2019 18601 16.1
6/1/2019 18905 15.9
7/3/2019 19259 15.9
7/13/2019 19425 16.2
8/1/2019 19669 16.3
9/1/2019 19878 16.4

I haven't succeeded in using BBCode to format this as a table.

This is almost all L1 charging at 8 amps, maybe a couple of times at 12 amps and one L2 session to get the car home from the dealer (16K miles, September 2018). As you can see, I don't drive much. The car is plugged in almost all the time, set to Rate and Departure charging. On the PG&E EV-A plan, this is almost all at night. I'm retired, so the car doesn't sit in a parking lot for very long. Sometimes when I return from a drive on a hot day I'll charge Immediate for 5 or 10 minutes just so battery cooling will kick in.

The GOM currently shows 72 miles. I don't have LRR tires and live on a hill, so I don't get much regen starting out from full.

There seems to be a recent upward trend in capacity. It will be interesting to see what the capacity is on Oct. 1.
I saw an increase in capacity on my 2016 Spark EV too. It rose from 15.5 to 15.8 and then slowly came back down to 15.5.

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