Mesasand
Posts: 11
Joined: Sat Jan 19, 2019 10:14 pm
Location: Las Vegas, NV

Re: Battery degredation

Thu May 02, 2019 1:19 pm

My recently purchased 2016 Spark was a Certified Pre Owned. I also purchased an OBD2 port to monitor my car’s diagnostics. From the day I got it, it has shown a total capacity of 15.9 kWh. It seems others are showing much higher capacity, more in the 18-19kWh range.

At what point does the battery capacity degradation become a warranty issue? And is it different for a CPO?
Mesasand
—————-
2016 Spark EV LT2, 30k miles

MrDRMorgan
Posts: 961
Joined: Wed Oct 30, 2013 7:27 am
Location: Manteca, California

Re: Battery degredation

Thu May 02, 2019 3:06 pm

Mesasand wrote:
Thu May 02, 2019 1:19 pm
My recently purchased 2016 Spark was a Certified Pre Owned. I also purchased an OBD2 port to monitor my car’s diagnostics. From the day I got it, it has shown a total capacity of 15.9 kWh. It seems others are showing much higher capacity, more in the 18-19kWh range.

At what point does the battery capacity degradation become a warranty issue? And is it different for a CPO?
You can find the information you need in the Chevrolet Limited Warranty and Owner Assistance Information booklet. Here is the link-

https://my.chevrolet.com/content/dam/gm ... dPrint.pdf. Refer to page 14.

8 years or 100K miles or >40% battery degradation in that period of time or mileage; which ever comes first.

My 2016 Spark EV 2LT only has 18.5K miles on the ODO and the TorquePro measured battery capacity is already 15.5 kWh. Assuming a new battery had 19 kWh, my battery needs to degrade below 11.4 kWh to become a warranty issue AND as long as it occurs within the specified time or mileage limits.

RSC
Posts: 33
Joined: Thu Sep 20, 2018 5:45 am

Re: Battery degredation

Sat May 04, 2019 12:37 pm

MrDRMorgan wrote:
Mon Apr 29, 2019 2:37 pm
I have a 2014 Spark EV 2LT w/o DCFC and it only has 18054 miles on the ODO. The battery capacity, as measured by TorquePro, has dropped from 17.2 kWh to 16.2 kWh over the last 3910 miles. This car is mainly charged using an L1 EVSE set to 12 amps.

I also have a 2016 Spark EV 2LT with DCFC and it only has 18351 miles on the ODO. The battery capacity, as measured by TorquePro, has dropped from 16.6 kWh to 15.5 kWh over the last 8067 miles. This car is mainly charge using an L2 EVSE and, much less often, at EVgo DCFC stations.

Right now I am only charging to 80-85% SoC and discharging to an SoC no lower than 25% to see if charging to 100% is the culprit. I will be running this test for the next 6 months or more to see if there is also a seasonal variation due to air temperatures.
Sounds like you could use a control. My car might be appropriate. I have a 2015 purchased off-lease as a CPO. Currently it has 18590 miles and I'm getting 16.x kWh according to the energy display. I recently got an OBD2 adapter but haven't yet set up Torque Pro. I might try to get to it this week and might have to ask questions if I run into difficulties. I've recently being doing the delayed departure (9 am) and disconnecting at 7 am, but am thinking about going back to my usual charging routine. This way my car could be compared to yours over the next 6 months. I'm using the stock L1 EVSE set to 8 amps.
Ray
2015 Spark EV 1LT, DCFC

MrDRMorgan
Posts: 961
Joined: Wed Oct 30, 2013 7:27 am
Location: Manteca, California

Re: Battery degredation

Sat May 04, 2019 1:09 pm

RSC wrote:
Sat May 04, 2019 12:37 pm
MrDRMorgan wrote:
Mon Apr 29, 2019 2:37 pm
I have a 2014 Spark EV 2LT w/o DCFC and it only has 18054 miles on the ODO. The battery capacity, as measured by TorquePro, has dropped from 17.2 kWh to 16.2 kWh over the last 3910 miles. This car is mainly charged using an L1 EVSE set to 12 amps.

I also have a 2016 Spark EV 2LT with DCFC and it only has 18351 miles on the ODO. The battery capacity, as measured by TorquePro, has dropped from 16.6 kWh to 15.5 kWh over the last 8067 miles. This car is mainly charge using an L2 EVSE and, much less often, at EVgo DCFC stations.

Right now I am only charging to 80-85% SoC and discharging to an SoC no lower than 25% to see if charging to 100% is the culprit. I will be running this test for the next 6 months or more to see if there is also a seasonal variation due to air temperatures.
Sounds like you could use a control. My car might be appropriate. I have a 2015 purchased off-lease as a CPO. Currently it has 18590 miles and I'm getting 16.x kWh according to the energy display. I recently got an OBD2 adapter but haven't yet set up Torque Pro. I might try to get to it this week and might have to ask questions if I run into difficulties. I've recently being doing the delayed departure (9 am) and disconnecting at 7 am, but am thinking about going back to my usual charging routine. This way my car could be compared to yours over the next 6 months. I'm using the stock L1 EVSE set to 8 amps.
I found the following HV battery capacity information from Chevrolet Product Information documents for each model year:

2014 Spark EV - 21.0 kWh
2015 Spark EV - 18.4 kWh
2016 Spark EV - 19.0 kWh

RSC
Posts: 33
Joined: Thu Sep 20, 2018 5:45 am

Re: Battery degredation

Sat May 04, 2019 3:42 pm

MrDRMorgan wrote:
Sat May 04, 2019 1:09 pm
I found the following HV battery capacity information from Chevrolet Product Information documents for each model year:

2014 Spark EV - 21.0 kWh
2015 Spark EV - 18.4 kWh
2016 Spark EV - 19.0 kWh
That's interesting. I had assumed that 2015 and 2016 were the same.
Ray
2015 Spark EV 1LT, DCFC

MrDRMorgan
Posts: 961
Joined: Wed Oct 30, 2013 7:27 am
Location: Manteca, California

Re: Battery degredation

Sun May 05, 2019 1:32 pm

RSC wrote:
Sat May 04, 2019 3:42 pm
MrDRMorgan wrote:
Sat May 04, 2019 1:09 pm
I found the following HV battery capacity information from Chevrolet Product Information documents for each model year:

2014 Spark EV - 21.0 kWh
2015 Spark EV - 18.4 kWh
2016 Spark EV - 19.0 kWh
That's interesting. I had assumed that 2015 and 2016 were the same.
Using data from the energy information screen in my leased 2015 Spark EV, my "calculated" battery capacity from 1000 miles to 8000 miles ranged between 18.09 kWh to 18.98 kWh. Between 8000 miles to 25000 miles it ranged between 17kWh an 18 kWh. At about 26000 miles, the Check Engine light came on and my calculated battery capacity dropped to right around 16 kWh and never improved even after the defective electrical component was replaced by the dealer. When I turned in the car at about 30k miles, the calculated battery capacity had dropped further to about 15.3 kWh.

RSC
Posts: 33
Joined: Thu Sep 20, 2018 5:45 am

Re: Battery degredation

Sun May 05, 2019 3:13 pm

MrDRMorgan wrote:
Sun May 05, 2019 1:32 pm
RSC wrote:
Sat May 04, 2019 3:42 pm
MrDRMorgan wrote:
Sat May 04, 2019 1:09 pm
I found the following HV battery capacity information from Chevrolet Product Information documents for each model year:

2014 Spark EV - 21.0 kWh
2015 Spark EV - 18.4 kWh
2016 Spark EV - 19.0 kWh
That's interesting. I had assumed that 2015 and 2016 were the same.
Using data from the energy information screen in my leased 2015 Spark EV, my "calculated" battery capacity from 1000 miles to 8000 miles ranged between 18.09 kWh to 18.98 kWh. Between 8000 miles to 25000 miles it ranged between 17kWh an 18 kWh. At about 26000 miles, the Check Engine light came on and my calculated battery capacity dropped to right around 16 kWh and never improved even after the defective electrical component was replaced by the dealer. When I turned in the car at about 30k miles, the calculated battery capacity had dropped further to about 15.3 kWh.
I got started today on setting up Torque Pro. I used the Bolt PIDs from Sean Graham (chevybolt.org). So far I've only set up one, the "Battery Capacity Guess", displayed as "Bat Cap Est" in Torque Pro. The displayed value is 16.1 kWh at 18601 miles. Is this the value we mean when we are talking about battery capacities as displayed by Torque Pro?

I guess this means 12.5% degradation. I'll log this over the next few months.

P.S.
I did this on a Chromebook because I thought that it would be easier to work with files and spreadsheets, and also a larger display.
Ray
2015 Spark EV 1LT, DCFC

MrDRMorgan
Posts: 961
Joined: Wed Oct 30, 2013 7:27 am
Location: Manteca, California

Re: Battery degredation

Sun May 05, 2019 4:39 pm

RSC wrote:
Sun May 05, 2019 3:13 pm
MrDRMorgan wrote:
Sun May 05, 2019 1:32 pm
RSC wrote:
Sat May 04, 2019 3:42 pm

That's interesting. I had assumed that 2015 and 2016 were the same.
Using data from the energy information screen in my leased 2015 Spark EV, my "calculated" battery capacity from 1000 miles to 8000 miles ranged between 18.09 kWh to 18.98 kWh. Between 8000 miles to 25000 miles it ranged between 17kWh an 18 kWh. At about 26000 miles, the Check Engine light came on and my calculated battery capacity dropped to right around 16 kWh and never improved even after the defective electrical component was replaced by the dealer. When I turned in the car at about 30k miles, the calculated battery capacity had dropped further to about 15.3 kWh.
I got started today on setting up Torque Pro. I used the Bolt PIDs from Sean Graham (chevybolt.org). So far I've only set up one, the "Battery Capacity Guess", displayed as "Bat Cap Est" in Torque Pro. The displayed value is 16.1 kWh at 18601 miles. Is this the value we mean when we are talking about battery capacities as displayed by Torque Pro?

I guess this means 12.5% degradation. I'll log this over the next few months.

P.S.
I did this on a Chromebook because I thought that it would be easier to work with files and spreadsheets, and also a larger display.
I now use TorquePro instead of the "calculated" capacity value derived from information taken from the Energy Information screen in the car. I am using the PIDS provided by Sean Graham and I use the PID !Battery Capacity as the measurement I use to monitor the battery capacity degradation in my 2014 and 2016 Spark EVs. So far, it has been very useful over time in showing the rate of HV battery degradation in both cars. I also monitor the SoC and all cell voltages plus the average cell voltage.

I believe the 16.1 kWh value you mentioned IS the battery capacity for your car. You can use this number as a starting reference. Over time - many charging cycles and weeks of operation - you will begin to see the degradation curve develop. I am currently monitoring the number of miles between points where the measured battery capacity drops by 0.1 kWh.

scrambler
Posts: 135
Joined: Sat Jan 14, 2017 4:11 pm

Re: Battery degredation

Sun May 05, 2019 6:10 pm

MrDRMorgan wrote:
Sun May 05, 2019 4:39 pm
I now use TorquePro instead of the "calculated" capacity value derived from information taken from the Energy Information screen in the car.
Have you found a consistent above or below difference in the derived capacity value between using the energy information screen of the car (being careful to note values when all numbers change almost at the same time as to minimize rounding errors) and TorquePro?

MrDRMorgan
Posts: 961
Joined: Wed Oct 30, 2013 7:27 am
Location: Manteca, California

Re: Battery degredation

Sun May 05, 2019 6:54 pm

scrambler wrote:
Sun May 05, 2019 6:10 pm
MrDRMorgan wrote:
Sun May 05, 2019 4:39 pm
I now use TorquePro instead of the "calculated" capacity value derived from information taken from the Energy Information screen in the car.
Have you found a consistent above or below difference in the derived capacity value between using the energy information screen of the car (being careful to note values when all numbers change almost at the same time as to minimize rounding errors) and TorquePro?
I went back and looked at the Energy Information data I took for the first three years I had for my 2015 Spark EV. Many times the calculated value swung as much as +/- 1.0 kWh from the previous value. I find that the data taken using TorquePro is much, much, more stable and is easier to graph. But... if you collect enough data using the Energy Screen information over a long period of time and plot a linear trendline, you will still see an average degradation plot that should be reasonably accurate.

The TorquePro data for my 2014 spark EV shows a degradation rate of about 0.24 kWh per 1000 miles.

The Energy Information trendline for my 2015 Spark EV shows a degradation rate of about 0.11 kWh per 1000 miles.

The TorquePro data for my 2016 Spark EV shows a degradation rate of about 0.17 kWh per 1000 miles.

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