Questions and Data tracking

[Kermit]

I had my GOM range down to 11 miles with the last bar flashing yellowish/orange for the first time by forgetting to plug in several times this week.
When I got home I used Torque pro to read the individual cell voltages and they were at 3.50 volts and it was showing 10% battery charge left.

With the cells at 3.50 Volts the discharge is at about 95%. So the upper and lower end buffer on what is usable in the battery is only about 3% on both ends from my measurements. These voltages are the same as our Gen 2 Volt.

I wanted to add that when my car got low enough to ask if I wanted to turn the radio off that it did not cool the battery even though it was hot outside and has been cooling when properly charged every day.

 

[Kermit]

Data from this month's 100% charge (September.)
Previous Charge to 100% was 92 miles. This charge to 100% and the GOM is at 99 miles.
Previous Charge to 100% kWh was 16.5666676. This charge to 100% and the kWh remained at 16.5666676 kWh (odometer is at 15,279). The average was 5.4 mi/kWh this past month over 451.5 miles.
Temperatures have been in the upper 90's with car reading over 100F most days.
I was seeing as high as 7+mi/kWh in the mornings when the car didn't need battery cooling and as low as 3.1mi./kWh when the car was hot from sitting in the sun all day.

Fuel is $2.29/ gallon here now and electricity is $0.074 per kWh so I am getting about 125.3 miles out of what it costs for a gallon of gas right now (after assuming 75% efficiency of the electricity actually into the battery.)

181.98 MPGe (1 Gallon of Gas = 33.7kWh)

Energy Details before the full charge showed:
67% Driving and accessories, 10% climate setting, 9% battery conditioning with 84.0 kWh used.

 

[Kermit]

Today torque shows my capacity has gone up again to 16.733333 kWh

 

[Kermit]

Data from this month's 100% charge (October.) 10/05/19
Previous Charge to 100% was 99 miles. This charge to 100% and the GOM is at 108 miles.
Previous Charge to 100% kWh was 16.5666676. This charge to 100% and the kWh went up to 16.7333336 kWh (odometer is at 15,771). The average was 5.8 mi/kWh this past month over 492.4 miles.
Temperatures have still been in the 90's with car reading over 100F most days but some days were cooler this past month.

Fuel is $2.39/ gallon here now and electricity is $0.074 per kWh so I am getting about 140.5 miles out of what it costs for a gallon of gas right now (after assuming 75% efficiency of the electricity actually into the battery.)

195.46 MPGe (1 Gallon of Gas = 33.7kWh)

 

[Kermit]

Today's battery capacity reading was 16.5 kWh via EngineLink.
A couple other data points since we have now had our first night of below freezing temperatures (our car is parked outside not in a garage.)
When the car is remote started while plugged in it will heat the battery to 12C (53.6F) before the battery heater turns itself off.
When the battery was hot it would cool the battery to 28C (82.4F) before the battery coolant pump would shut off.

 

[RSC]

November readings (previously posting in another thread):

Date.......... Miles. Capacity (kWh)
05/5/2019 18601 16.1
06/1/2019 18905 15.9
07/3/2019 19259 15.9
08/1/2019 19669 16.3
09/1/2019 19878 16.4
10/2/2019 20190 16.0
11/1/2019 20611 16.0

Looks like the increase to 16.4 kWh was temporary.

 

[MrDRMorgan]

November readings (previously posting in another thread):

Date.......... Miles. Capacity (kWh)
05/5/2019 18601 16.1
06/1/2019 18905 15.9
07/3/2019 19259 15.9
08/1/2019 19669 16.3
09/1/2019 19878 16.4
10/2/2019 20190 16.0
11/1/2019 20611 16.0

Looks like the increase to 16.4 kWh was temporary.

I think the temporary jump may be mostly due to warmer ambient temperature. I saw a similar temporary jump last year too. But.... the overall trendline is still in a downward direction.
May 2019 - 18665 miles 15.4 kWh
July 2019 - 22476 miles 15.8 kWh
Nov 2019 - 25918 miles 15.2 kWh

 

[Kermit]

Today's battery capacity reading was 16.5 kWh via EngineLink.
A couple other data points since we have now had our first night of below freezing temperatures (our car is parked outside not in a garage.)
When the car is remote started while plugged in it will heat the battery to 12C (53.6F) before the battery heater turns itself off.
When the battery was hot it would cool the battery to 28C (82.4F) before the battery coolant pump would shut off.

We've had some cold nights (last night was 17F) and I have been looking to see if the battery heater was on while charging. The battery heater did not come on until I remote started the car to condition it this morning (~8am with departure set for 2PM which gets me to about 86% charged and closer to 80% charged after a remote start). I believe it must have come on at sometime because the outside air temp according to the car was 25.7F and the battery temp was 2C (35.6F) (Battery coolant temp was 33.8F). After the remote start it got up to 12C (53.6F) before turning off the battery heater.

I returned home from a short trip (still below freezing temps) and plugged it in to keep it charging while I was working on something else and when I checked again at 1PM the battery heat was on and the temperature was at 12C (55.4F on torque pro) as it approached 94% charged (again set at a 2pm departure.)

Compared to our Gen 2 Volt it's battery temp was 59F as it was nearing the end of it's charge.

It is interesting to see how low of a temperature it will charge at. The next night it is below freezing I will do an immediate charge instead of delayed to confirm if the battery heat turns on to get it to 2C and if it shuts off there or continues to heat or just just turns off until it nears the end of the charge.

With the car sitting out in the cold and not plugged and running the remote start the battery heater did not turn on with the battery reading was 3C.

 

[SparkE]

Shamelessly stolen from another forum :

Temperature has a large effect on the relative capacity of the cells. Take a Samsung ICR18650-26F cell as an example - not the same cells used in the Bolt but it is a Lithium based cell. The official datasheet from Samsung specifies the 100% capacity rating at 25C, but when the temperature is 0C (32F) or 40C (104F) the relative capacity drops to 80%. At -10C (14F) the capacity drops to 50%. If you want to log relative capacity data for the pack you also need to record the cell temperature because the relative capacity data will be skewed if the temperatures are all over the place.

So, I suggest that people collecting data on their EV batteries (with Torque Pro or similar) also start recording the cell temperature when the reading was taken.

 

[Kermit]

Shamelessly stolen from another forum :

Temperature has a large effect on the relative capacity of the cells. Take a Samsung ICR18650-26F cell as an example - not the same cells used in the Bolt but it is a Lithium based cell. The official datasheet from Samsung specifies the 100% capacity rating at 25C, but when the temperature is 0C (32F) or 40C (104F) the relative capacity drops to 80%. At -10C (14F) the capacity drops to 50%. If you want to log relative capacity data for the pack you also need to record the cell temperature because the relative capacity data will be skewed if the temperatures are all over the place.

So, I suggest that people collecting data on their EV batteries (with Torque Pro or similar) also start recording the cell temperature when the reading was taken.

Good info on the capacity vs temperature.
The issue I find with the temperature/data is that the capacity doesn't seem to update very often in the app (Enginelink or Torque Pro, both of which show the same capacity.) So if the car is cold or fully warmed up the capacity reads the same for several weeks. There must be some sequence that tells the car to recalculate the capacity. Our car doesn't show a change in the capacity reading after a full charge but it has changed twice since it's last full charge which happens about once a month.

 

[Kermit]

Data from this month's 100% charge (November.) 11/15/19
Previous Charge to 100% was 108 miles. This charge to 100% and the GOM is at 88 miles* (*This was after a full 20 minute pre-conditioning cycle.)
Previous Charge to 100% kWh was 16.7333336. It dropped twice between charges (10/31/19 - 16.50kWh and 11/2/19 16.43kWh) and again at today at the full charge. This charge to 100% and the kWh went down to 16.3666668 kWh (odometer is at 16,293). The battery was conditioned and was at 55.4F for this reading. The average was 5.5 mi/kWh this past month over 521.6 miles.
Temperatures were mild in October and dropped below freezing for the past week or two in November.

Fuel is $2.39/ gallon here now and electricity is $0.074 per kWh so I am getting about 133.2 miles out of what it costs for a gallon of gas right now (after assuming 75% efficiency of the electricity actually into the battery.)

185.35 MPGe (1 Gallon of Gas = 33.7kWh)

 

[RSC]

December readings:

Date.......... Miles. Capacity (kWh)
05/5/2019 18601 16.1
06/1/2019 18905 15.9
07/3/2019 19259 15.9
08/1/2019 19669 16.3
09/1/2019 19878 16.4
10/2/2019 20190 16.0
11/1/2019 20611 16.0
12/3/2019 20974 15.7

Getting colder in the garage.

 

[RSC]

January readings:

Date.......... Miles. Capacity (kWh)
05/5/2019 18601 16.1
06/1/2019 18905 15.9
07/3/2019 19259 15.9
08/1/2019 19669 16.3
09/1/2019 19878 16.4
10/2/2019 20190 16.0
11/1/2019 20611 16.0
12/3/2019 20974 15.7
01/1/2020 21176 15.7

 

[NORTON]

Happy New Year!

This is not very current as I'm past 75 k miles.
Readings are from the Energy Screen. I don't have Torque Pro working with the Bolt PIDs yet.
Is there a big difference in data between the two methods?

Mileage- date - % Used - kWh used - Present Capacity kWh
70001 8-29-19 81% 15 18.52
70488 9-14-19 59% 11 18.64
70597 9-16-19 59% 11 18.64
70696 9-18-19 56% 10.3 18.39
72131 10-21-19 80% 14.7 18.38
72467 10-28-19 78% 15.1 19.36

Did A123, the maker of the '14 Spark EV cells under rate them?
I read something about this.....

From wiki here: https://en.wikipedia.org/wiki/Chevrolet_Spark#Spark_EV
(MY 2015+) 19 kWh lithium-ion battery by LG Chem.
MY 2014: 21.3 kWh Lithium iron phosphate by A123, claimed as nano-phosphate Li-ion battery.

 

[RSC]

Is there a big difference in data between the two methods?

As nearly as I can tell, the two methods are pretty close. I can't be very accurate using the energy screen though, since I'm almost always at the top end of the battery. I can only think of three occasions that I've gone below 50% state of charge. Typically for me the energy screen will show something like 3.2 kWh and 20% used.

I know that you already know this, and it's been pointed out before, but for newcomers, you have to measure energy used since the last full charge. Partial charges will not give a valid result.

 

[MrDRMorgan]

Happy New Year!

This is not very current as I'm past 75 k miles.
Readings are from the Energy Screen. I don't have Torque Pro working with the Bolt PIDs yet.
Is there a big difference in data between the two methods?

Mileage- date - % Used - kWh used - Present Capacity kWh
70001 8-29-19 81% 15 18.52
70488 9-14-19 59% 11 18.64
70597 9-16-19 59% 11 18.64
70696 9-18-19 56% 10.3 18.39
72131 10-21-19 80% 14.7 18.38
72467 10-28-19 78% 15.1 19.36

Did A123, the maker of the '14 Spark EV cells under rate the them?
I read something about this.....

From wiki here: https://en.wikipedia.org/wiki/Chevrolet_Spark#Spark_EV
(MY 2015+) 19 kWh lithium-ion battery by LG Chem[48]
MY 2014: 21.3 kWh Lithium iron phosphate by A123, claimed as nano-phosphate Li-ion battery.

All I can say is WOW! Something is sure different! I know there are other Spark EV drivers on the road who also have high mileages of 75k and higher. It would be nice to know their current mileage and battery capacity too. I am really reaching, but I wonder if 2014 Spark EVs assembled early in the model year had the A123 battery and 2014 Spark EVs assembled later in the model year were switched to the LG battery.

The battery capacity for my 2014, leased 2015 and 2016 Spark EVs all were, are, or soon will be, around 15-15.5 kWh at 30k miles. In fact, my 2016 Spark EV battery capacity is currently 14.8 kWh at 27K miles as measured by TorquePro. A friend of mine, who also had a leased 2015 Spark EV, had 14.8 kWh at about 34k miles. when he returned his car to the dealer.

I haven't done the "calculated" battery capacity for a while so I will do it for both my 2014 and 2016 and compare it with the TorquePro values.

 

[scrambler]

I am down to 13.6kWh usable on my 2014 Spark steady decline year over year, and I only do about 7000 miles a year with it.

 

[MrDRMorgan]

I am down to 13.6kWh usable on my 2014 Spark steady decline year over year, and I only do about 7000 miles a year with it.

How many miles are on your ODO? The linear trendline for my TorquePro battery capacity data shows I will hit 13.5 kWh in about 8000 miles (in about 2 years) when my 2014 ODO hits 30K miles.

 

[Kermit]

Data from this month's 100% charge (December.) 12/09/19
Previous Charge to 100% was 88* miles. This charge to 100% and the GOM is at 97 miles
Previous Charge to 100% kWh was 16.3666668. This charge to 100% and the kWh went down to 16.2000008 kWh (odometer is at 16,485). The battery was at 57.2F for this reading. The average was 5.9 mi/kWh this past month over 191.8 miles.
Temperatures were mild in November and beginning of December and dropped below freezing only a few days.

Fuel is $2.39/ gallon here now and electricity is $0.074 per kWh so I am getting about 142.9 miles out of what it costs for a gallon of gas right now (after assuming 75% efficiency of the electricity actually into the battery.)

198.83 MPGe (1 Gallon of Gas = 33.7kWh)

 

[NORTON]

.... The battery was conditioned and was at 57.2F for this reading. ....

What does this mean?
I understand you can see battery temp in the Torque app.