Two identical sparks, 2 very different range estimates...

[scrambler]

I got the numbers on the 2015 spark showing the lower range estimate today:
After a 50 mile trip, shows 63% used and used 10.4kwh (53% driving and 10% climate control) = so 16.50kwh useable battery??
Isn't that low?

Keep in mind that there is some imprecision in the calculation as the percentage only increments in full % and the kWh in .1 kWh
So you can have up to .9% error on the driving % and .09 error on the kWh, if they cumulate, it can make the calculation of the capacity vary by almost 1 kWh.
To minimize imprecision error, watch the % number and the kWh number, and try to note them when they both change almost at the same time (do keep an eye on the road )

Also make sure you are adding all non zero percentages (driving, conditioning and climate), but if possible make measurement when conditioning and climate are at zero, as each of them carries its own imprecision, so if you have to add more than one percentage, the imprecision goes up.

Accounting for the imprecision of the measures, what you found both on the usable capacity and the usage explains the difference of range you mentioned in your first post.

To recap 2016 over 2015
87 over 67 +29%
4.6 m/kwh over 4.1 m/kwh is +12%
17.8 kwh over 16.5 kwh is + 8%

Range based on above number would be 4.6 x 17.8 = 82 miles over 4.1 x 16.5 = 67.65 miles

You can fine tune your estimated usable capacity with more measures following info given above and in other posts.
But between a bit less capacity and a more aggressive driving, your estimated range difference makes sense.

 

[MrDRMorgan]

"Also make sure you are adding all non zero percentages (driving, conditioning and climate), but if possible make measurement when conditioning and climate are at zero, as each of them carries its own imprecision, so if you have to add more than one percentage, the imprecision goes up."

Scrambler, you are correct and I should have made this point more clear. Thanks for the clarification.

 

[MrDRMorgan]

Did the test today on the higher-range 2016.
Drove about 30 miles on the freeway with almost no re-gen.

Came out to used 67% and 11.9kwh.
So 11.9 / .67 = 17.8 kwh usable battery

So when compared to the 2015 spark, the 2016 is showing about 1.5kwh MORE that the 2015 usable at 16.5kwh.

And this is with the lower 2015 Spark number showing some re-gen as half of the 50 mile commute is thru the city with
many stoplights, so the 2015 maybe be ever less than 16.5?? Because it is adding kw during the commute?

For your 2015, try repeating the same freeway route and speed as you used for the 2016. That will give you a better comparison. 17.8 kWh for your 2016 is what I would expect to see. I am going to run the test on my 2016 today and follow with my 2014.

Below are my results for yesterday and today. Only DRIVE had values greater than zero.

2015 Spark EV battery capacity calculation at the end of 35.5 miles was 15.8 kWh [6.0 kWh used or 38% of the battery]. Speed was set to 60 mph and outside temp was 59 deg. F. ODO read 24008 miles at the end of the test trip. Trip meter info: 35.5 miles @ 5.6 mi / kWh. Est range is 89 miles [5.6 mi / kWh x 15.8 kWh].

2014 Spark EV battery capacity calculation at the end of 33.9 miles was 17.8 kWh [6.4 kWh used or 36% of the battery]. Speed was set to 60 mph and outside temp was 53 deg. F. ODO read 12306 miles at the end of the test trip. Trip meter info: 33.9 miles @ 5.3 mi/kWh. Est range is 94 miles [5.3 mi / kWh x 17.8 kWh].

2016 Spark EV battery capacity calculation at the end of 33.8 miles was 17.4 kWh [5.9 kWh used or 34% of the battery]. Speed was set to 60 mph and outside temp was 59 deg. F. ODO read 7776 miles at the end of the test trip. Trip meter info: 33.8 miles @ 5.8 mi / kWh. Est range is 101 miles [5.8 mi / kWh x 17.4 kWh].

 

[CSW]

Well, it seems to be issue resolved.

I had the wife drive more efficiently (less of a speed-demon) in her 2016 for 2 days.
Then I drove less-efficiently for 2 days in my 2015, tryin to match her 4.1kwh/mi average, and I did.

Yesterday morning both cars were showing 76 miles of range after a full charge......

I still need to do the battery capacity test on the 2015, and I will asap, but I suspect it will be very close to the 2016.

I just did not even think of the average kwh/mi factor because it was so different for so long, AND I do not try to
drive overly efficient, I just drive normal, and I did not consider my wife was worse than me on efficiency. Haha!

Thanks for all the good info and help!

 

[CSW]

2014 Spark EV battery capacity calculation at the end of 33.9 miles was 17.8 kWh [6.4 kWh used or 36% of the battery]. Speed was set to 60 mph and outside temp was 53 deg. F. ODO read 12306 miles at the end of the test trip. Trip meter info: 33.9 miles @ 5.3 mi/kWh. Est range is 94 miles [5.3 mi / kWh x 17.8 kWh].

2016 Spark EV battery capacity calculation at the end of 33.8 miles was 17.4 kWh [5.9 kWh used or 34% of the battery]. Speed was set to 60 mph and outside temp was 59 deg. F. ODO read 7776 miles at the end of the test trip. Trip meter info: 33.8 miles @ 5.8 mi / kWh. Est range is 101 miles [5.8 mi / kWh x 17.4 kWh].

I find it interesting that the 2014 has a 21kwh battery and the 2016 has a 19kwh, yet the useable capacity is almost the same. Strange GM would do it that way.

 

[SparkevBlogspot]

I find it interesting that the 2014 has a 21kwh battery and the 2016 has a 19kwh, yet the useable capacity is almost the same. Strange GM would do it that way.

That's because 2014 is 3 to 4 years older and has correspondingly higher battery degradation. New 2014 would have much higher capacity than new 2016, but you need a time machine to compare them since the batteries degrade just by sitting there.

 

[MrDRMorgan]

I find it interesting that the 2014 has a 21kwh battery and the 2016 has a 19kwh, yet the useable capacity is almost the same. Strange GM would do it that way.

That's because 2014 is 3 to 4 years older and has correspondingly higher battery degradation. New 2014 would have much higher capacity than new 2016, but you need a time machine to compare them since the batteries degrade just by sitting there.

I revisited some charging data I recorded starting in March of 2016 and going through June of 2017 for my 2014 and 2015 Spark EVs. The data covers well over 100 L2 charging sessions per vehicle. The average battery capacity for the 2014 Spark EV is 18.20 kWh and the average battery capacity for the 2015 Spark EV is 17.57 kWh as of the end of June 2017. I also plotted all of the average data by month starting in March 2016. The 2014 Spark EV appears to have lost about 1.5 kWh and the 2015 Spark EV was relative stable.

 

[MrDRMorgan]

What I do know is adding charge back into the battery will cause the DRIVE value to decrease while the kWh value remains the same. This results in a calculated battery capacity value higher that the actual value. To verify this, I recorded the DRIVE and kWh values shown on the Energy Information screen in my 2016 Spark EV. I then connected the car to my L2 EVSE and charged for about 2 hours. The DRIVE value decreased from 62% to 50%. The kWh value did not change.

I don't know about additional charging with the EVSE, but this is not my experience with regen.

If the car shows a % used and a kWh used and I get a lot of regen, both the % and the kWh used will go back down. So I don't think Regen affects the accuracy of that reading

On Friday I will be driving over a couple of passes where the downhill side does generate considerable regen as I drive in L. I'll try to remember to note the DRIVE % and kWh Used values at the top and bottom to see how the DRIVE and kWh values change. I'll report my findings on Saturday.

Update: This afternoon, I decided to re-test my 2015 Spark EV using the same route as I did in September. I drove on the freeway with the cruise control set to 60 mph. I also configured the display to show any regeneration. I actually had a little regeneration due to overpasses, under passes, and slowing down for traffic but not a amount to be significant. I drove 35.47 miles at an average of 5.6 mi / kWh [6.33 kWh consumed]. The Energy Information screen for DRIVE read 40% at the end of my drive. The calculated HV battery capacity is 15.83 kWh which is almost 1.3 kWh lower than my September calculation and is consistent with a recent problem with the car.

In late October the yellow "Service Vehicle Soon" light came on. I took the car to the dealer and they said there was a problem with the DC charging unit so a repair part was ordered. So far, the part has not arrived. When I got the car back, the light was out, and has remained out, but my battery capacity took a hit and today's calculation is consistent with the drop in full-charge range I have been seeing. I will have to wait to see if the repair part fixes the problem or the dealer finds the problem is really with the HV battery.

Update: I monitored the DRIVE % and kWh Used as I decended the two passes and both times the DRIVE % and kWh Used both decreased simultaneously. So much for blaming REGEN on the HV battery capacity calculations.

 

[CSW]

Ok, I just completed the capacity test on my "lower-range" 2015.

I did 30 miles, all freeway, zero re-gen, no climate controls and I used exactly 10kwh and it showed 63% used.....
(there was a lot of elevation gain and I was going about 75mph)

So this indicates only 15.9 kwh of available battery?!

This is almost 2kw LESS than my 2016 Spark....

Not good. What is going on here? ??!!!

This is makin me not wanna purchase either of these Sparks when the lease is up.

 

[Planerench]

My capacity numbers are generally worse when I work the battery hard. There is a rule of battery capacity measurement that the rate of discharge is critical to accurate capacity calculation. The rate per hour is the standard and is referred to as 1C. 21kwh would require putting a 21kw load on the battery for 1 hour. That would be the only way to scientifically test the battery. We have to perform cap checks on aircraft batteries at regular intervals to assure rated capacity. Otherwise, tracking the data points and averaging them is all we have for trend and capacity numbers.

 

[NORTON]

Ok, I just completed the capacity test ...
I did 30 miles, all freeway, zero re-gen, no climate controls and I used exactly 10kwh and it showed 63% used.....
(there was a lot of elevation gain and I was going about 75mph)
....

Not good. What is going on here? ??!!!
..

You need more data points. ONE test is not enough for an accurate measurement.

Look at some of the plots people have posted on this subject.
The results can vary a lot within one month's worth of testing.
Start a spread sheet. Patience.

 

[CSW]

My capacity numbers are generally worse when I work the battery hard. There is a rule of battery capacity measurement that the rate of discharge is critical to accurate capacity calculation. The rate per hour is the standard and is referred to as 1C. 21kwh would require putting a 21kw load on the battery for 1 hour. That would be the only way to scientifically test the battery. We have to perform cap checks on aircraft batteries at regular intervals to assure rated capacity. Otherwise, tracking the data points and averaging them is all we have for trend and capacity numbers.

OOOhhh, interesting, I did not know this, I figured draining the battery is drainin the battery! haha!

Yes, on the 2016 I did the test on flat ground whereas the 2015 there was a lot of uphill action.

Welp, I will re-run the test on the 2016 on the uphill like the 2015 and go about the same speed and see how it goes.

All is not lost yet! Whoot!

 

[MrDRMorgan]

2014 Spark EV battery capacity calculation at the end of 33.9 miles was 17.8 kWh [6.4 kWh used or 36% of the battery]. Speed was set to 60 mph and outside temp was 53 deg. F. ODO read 12306 miles at the end of the test trip. Trip meter info: 33.9 miles @ 5.3 mi/kWh. Est range is 94 miles [5.3 mi / kWh x 17.8 kWh].

2016 Spark EV battery capacity calculation at the end of 33.8 miles was 17.4 kWh [5.9 kWh used or 34% of the battery]. Speed was set to 60 mph and outside temp was 59 deg. F. ODO read 7776 miles at the end of the test trip. Trip meter info: 33.8 miles @ 5.8 mi / kWh. Est range is 101 miles [5.8 mi / kWh x 17.4 kWh].

I find it interesting that the 2014 has a 21kwh battery and the 2016 has a 19kwh, yet the useable capacity is almost the same. Strange GM would do it that way.

I believe the 2015 and 2016 Spak EVs both use the same LG HV battery. Yet, the 2016 performs more like my 2014 although the 2014 only has about 5k more miles on the ODO. Regardless, I like it!

 

[MrDRMorgan]

My capacity numbers are generally worse when I work the battery hard. There is a rule of battery capacity measurement that the rate of discharge is critical to accurate capacity calculation. The rate per hour is the standard and is referred to as 1C. 21kwh would require putting a 21kw load on the battery for 1 hour. That would be the only way to scientifically test the battery. We have to perform cap checks on aircraft batteries at regular intervals to assure rated capacity. Otherwise, tracking the data points and averaging them is all we have for trend and capacity numbers.

OOOhhh, interesting, I did not know this, I figured draining the battery is drainin the battery! haha!

Yes, on the 2016 I did the test on flat ground whereas the 2015 there was a lot of uphill action.

Welp, I will re-run the test on the 2016 on the uphill like the 2015 and go about the same speed and see how it goes.

All is not lost yet! Whoot!

Isn't this Fun?

 

[Planerench]

Today I had some errands to run and long story short, I rolled into my garage in turtle mode with 3-4 miles left. A new low for my Spark. I drove 91 miles today with a bit of L1 charge from work.

 

[MrDRMorgan]

Today I had some errands to run and long story short, I rolled into my garage in turtle mode with 3-4 miles left. A new low for my Spark. I drove 91 miles today with a bit of L1 charge from work.

Isn't it a bit cold there right now? Did you drive in "freezing" mode or power up the heater?

 

[Planerench]

Today I had some errands to run and long story short, I rolled into my garage in turtle mode with 3-4 miles left. A new low for my Spark. I drove 91 miles today with a bit of L1 charge from work.

Isn't it a bit cold there right now? Did you drive in "freezing" mode or power up the heater?

 

[Planerench]

Today I had some errands to run and long story short, I rolled into my garage in turtle mode with 3-4 miles left. A new low for my Spark. I drove 91 miles today with a bit of L1 charge from work.

Isn't it a bit cold there right now? Did you drive in "freezing" mode or power up the heater?

The commute to work is preheated interior out of a 55 degree garage and roll on the heat as necessary during the 23 mile drive. The drive home is from outside parking topped off from L1 at work, heat as required. Range from full has been 65ish. Last night was a second trip all the way into north end Boise at rush hour just minutes after getting home from the Boise Airport. My boy was with me, wearing both our jackets, counting down the percentage used as we returned home. Good numbers to know. Winter tires, dark is about as bad as it can get.

 

[MrDRMorgan]

Today I had some errands to run and long story short, I rolled into my garage in turtle mode with 3-4 miles left. A new low for my Spark. I drove 91 miles today with a bit of L1 charge from work.

Isn't it a bit cold there right now? Did you drive in "freezing" mode or power up the heater?

The commute to work is preheated interior out of a 55 degree garage and roll on the heat as necessary during the 23 mile drive. The drive home is from outside parking topped off from L1 at work, heat as required. Range from full has been 65ish. Last night was a second trip all the way into north end Boise at rush hour just minutes after getting home from the Boise Airport. My boy was with me, wearing both our jackets, counting down the percentage used as we returned home. Good numbers to know. Winter tires, dark is about as bad as it can get.

In December last year I was seeing an average monthly range of 75 miles for my 2015. The 2014 range was just slightly higher. Temperatures here have been in the low to mid 30s in the early morning hours and rise to the mid 60s around 1pm. It is 33 deg. F this morning and my garage temperature is 55 deg. F. This month I expect my average GOM range after charging will be lower but how much is yet to be determined. After a full charge last night, the 2014 GOM read 92 and the 2015 GOM read 83.

 

[CSW]

I just completed the same range/battery capacity test for my higher 2016 spark .....

Short story: higher 2016 spark has 1.7 kw more useable capacity than lower 2015 spark.

Did exact conditions, same route, same speed, same weight in car, about same temp outside.

The numbers:
2015 used 10kw shows 63 % = 15.9 kw avail
2016 used 10.2kw shows 58% = 17.6 kw avail

Is this normal?
The 2015 is one year older than the 2016 and has 10k more miles on it. (2016 has 14k and 2015 has 24k)
Normal to loose 1.7 kw in a year and 10k miles?
At 4.5mi per kwh average, this is about 7.7 miles of range difference.

Last thing, so I guess you have to get over 35% degraded battery before Chevy replaces it under
8 year/100k mile warranty? Where do they calculate the 35% from? 19kwh? 18? 17.5?

I wonder because at this point, I still plan on buying the 2015 spark and not the 2016.