Miles vs age on battery degrading question

[kevin]

Data, or it's just an opinion!

I don't have the know how to make graphs to grab data points as you have done in this thread (but I should probably look it up!). I am strictly basing this off of the fact that it was advertised at having an 82 mi range fully charged, where as my average range is only about 60 miles (70, driving conservatively).

Also, I am not complaining or upset if battery degradation has occurred. Of course I know that it's an inevitable reality with any current energy storage medium. I still get way more mileage out of a charge then I ever need on a day to day basis.

This does, however, beg another question that has already been discussed and speculated upon. With an 8 year warranty on the battery, will Chevy replace units that have become heavily degraded without having actually failed?

The range depends a great deal on how you drive it.

What was the range when the car was new?

Mine declined from ~115 down to 98 over 22,000 miles. The battery reduced in capacity from 19.5kWh down to 16.5kWh.

I have a few posts on this forum with the data from my 2014 Spark EV, but not every car will be the same.

kevin

 

[MrDRMorgan]

Trying to get a handle on the "real" battery degradation numbers has been quite difficult until now. The Idaho National Laboratory has been testing the batteries on 4 different 2015 Spark EVs. Go to this web address to see the test results: https://avt.inl.gov/vehicle-button/2015-chevrolet-spark.

Yes, the batteries do degrade.

 

[evboy]

Trying to get a handle on the "real" battery degradation numbers has been quite difficult until now. The Idaho National Laboratory has been testing the batteries on 4 different 2015 Spark EVs. Go to this web address to see the test results: https://avt.inl.gov/vehicle-button/2015-chevrolet-spark.

Yes, the batteries do degrade.

they didnt test 2014 model. what a bummer

 

[emotodude]

How are you guys determining maximum battery capacity?

 

[MrDRMorgan]

How are you guys determining maximum battery capacity?

I think the best way found to make this calculation is to go to the energy information screen and divide the number of kwh used by the percent used. This assumes you start with a full charge so the screen reads 0% and 0 kWh to start and, at the end point, you have used more than 50% of the battery. The amount of regeneration generated will have some effect on the % used so your driving should be uniform between measurement points as you collect data. I have found averaging measurements by month seems to work best.

Another way is to start with a fully charged battery. Make sure the energy info screen resets to zero. Reset the trip meter to zero. At any point before the next charging cycle, you can add the blue ball GOM number to the miles traveled number and divide the total by the mi/kWh number to get an estimate of the battery capacity.

For example - at my last full charge last night for my 2014 Spark EV 2LT:
1. Energy Info screen before charging showed 66% of the battery used or 11.3 kWh. This gave 17.12 kWh as my battery capacity.
2. My trip meter miles traveled + remaining GOM totaled 101 miles at 5.9 mi/kwh. This also gave 17.12 kWh.

For March 2016 I averaged 18.94 kWh with an average full-charge range of 106 miles
For March 2017 I averaged 17.72 kWh with an average full-charge range of 98 miles.

Note: these two methods do not always match due to rounding of displayed information.

The car currently has 10k miles on the ODO with 5.5K miles driven between March 2016 and March 2017.

 

[agdodgerfan]

Today I used my battery down to 1%, then I charged to 100%. Using level 3 charging my battery took 16.99 kwh. I know a small portion of that is wasted on charging but at 77,200 miles I am guessing my capacity to be around 17kwh. I have a 2014 so original capacity is listed at 21kwh. From what I have heard in the forum only 18 kwh was truly available. Hope this info helps. I might try it on level 2 next week.

 

[SparkevBlogspot]

DCFC is only about 94% efficient, so the actual battery capacity would be close to 16 kWh if DCFC to 100% was 17 kWh. At 77.2K miles, that ain't bad at all. In my as yet to be written blog post, that's about what one would see at about 70K miles if not for strange anomaly I see with my battery.

 

[NORTON]

How are you guys determining maximum battery capacity?

I don't understand monitoring the charge data (goes-in) instead of the usage display data (goes-out).
Batteries are nowhere near 100% efficient with goes-in vs goes-out.
Plus high-end EV's have a Thermal Management System and they all have a Battery Management System to keep the cell groups balanced. Both of these consume power.

The Leaf page data: kWh used / - - xx% used is all we have. And plotting those numbers shows a spread. You can't make a call from one data point.
Plotting those numbers over time is probably the best way to see a trend and get a current 'average' Battery Capacity number.

 

[ncerna]

Check AutoTrader magazine. You can find some good deals on there. I saw a 2016 Chevy Spark here in California that was selling for $12000 from a dealer, with around 700 miles. I'm sure you can haggle them down to $11,000.

 

[evboy]

Check AutoTrader magazine. You can find some good deals on there. I saw a 2016 Chevy Spark here in California that was selling for $12000 from a dealer, with around 700 miles. I'm sure you can haggle them down to $11,000.

i doubt u can haggle that down to 11k. that is priced to sell. i would scoop that up if i was in the market for one. its the cheapest on autotrader. all the other ones i posted about for 12k a few months ago sold quick.

 

[agdodgerfan]

I tried it again I ran my battery down to basically zero because it popped a message saying charge depleted This time I used level 2 Charging and this definitely does not add up it says I took 21 kilowatts using level 2 Charging and this is from chargepoint site I think they're just guesstimating the amount of charge. If original capacity is 21 kilowatt how does it absorb 21 kilowatts is chargepoint overcharging people? My car is now over 81000 miles.

 

[Taxman]

Charging is not 100% efficient. That's why batteries get hot when you charge them, some of those kWs are turning into heat, not chemical potential energy.
And some of those kWs never make it to the battery, it takes electricity to run the car's systems, especially the battery cooling system, while you charge the battery.

 

[SparkevBlogspot]

L2 charging is only about 85% efficient, depending on temperature. 21*0.85 = 17.9 kWh. Since 2014 had about 19.8 kWh usable, it seems you've lost about 10%.

81K miles, wow, that is a lot.

 

[MrDRMorgan]

L2 charging is only about 85% efficient, depending on temperature. 21*0.85 = 17.9 kWh. Since 2014 had about 19.8 kWh usable, it seems you've lost about 10%.

81K miles, wow, that is a lot.

If, at 80K miles, I still have 90% usable battery left for my 2014 Spark EV, I am going to be a VERY HAPPY CAMPER! I only put on about 5k miles per year driving 100% locally so that will be many years in the future.