DDMan11
Posts: 7
Joined: Thu Jun 26, 2014 6:34 pm

Battery degredation

Wed Mar 02, 2016 8:18 pm

I've had my 2014 Spark for now a year and 8 months. The car now has 23k on the odometer but my battery life has suffered greatly. I began with 80-100 miles of range (depending on my driving style and weather), but now I'm getting 60-75 miles.

I've used the built in battery usage meter, and today, I had 8.8 KW used at 50% battery life. This indicates I have somewhere around 17.6 KW total battery life. That is a nearly 16% battery life lost. Does anyone else have this type of battery deterioration? Anyone know what Chevy's battery life warranty is, or when they will do something about excessive battery life loss? If I hit the 20% mark, I won't be able to make my daily round trip.

SparkevBlogspot
Posts: 499
Joined: Mon May 25, 2015 12:19 pm

Re: Battery degredation

Wed Mar 02, 2016 8:42 pm

DDMan11 wrote:I've had my 2014 Spark ... somewhere around 17.6 KW total battery life.
Based on another with 2014, that level seems about right.

http://www.mychevysparkev.com/forum/vie ... 961#p14961

I don't know how diligent people "baby" their batteries or how much better it'd be to follow conventional rules, them being

1. Don't charge to full.
2. Don't drive to empty.
3. Keep it between 20% to 80% while operating.
4. If not operating, keep it at about 50% level.

Of course, above are not realistic for battery EV, better suited to hybrids. For example, if you kept it parked at 50% level, and can only drive to 20%, that's only 30% usable, which is 80*.3 = 24 miles range.

DDMan11
Posts: 7
Joined: Thu Jun 26, 2014 6:34 pm

Re: Battery degredation

Thu Mar 03, 2016 12:36 pm

Realistic? No, not when I have a 60 mile trip I have to take on a daily basis. Thank god this car is a lease!

The car gets charged to full just about every time it's driven more than 10 miles or so. It gets charged to full 5x per week, sometimes more often. I also don't drive nicely (80+ on the freeway, and willingly use the AC/Heater). Again, range isn't so much my concern yet, but it will be. If I can't turn my heater on in the middle of winter or the AC on in the middle of summer and make my round trip... we have a big problem. When I got the car, I made the entire trip with the AC on with 20+ miles of range left.

I just know Leaf drivers had their batteries replaced because if extreme degradation. Curious if that will happen with the Spark.

SparkevBlogspot
Posts: 499
Joined: Mon May 25, 2015 12:19 pm

Re: Battery degredation

Thu Mar 03, 2016 5:06 pm

DDMan11 wrote:Nissan ... batteries replaced because if extreme degradation. Curious if that will happen with the Spark.
If you have warranty booklet, check page 14. Apparently, there is something about degradation warranty. Nissan will not replace the pack with new, only with similar that exceeds minimum (if they can find one). I suspect Chevy will do the same.

As for range, my latest blog post is about range using some made up data. ;-) It might be of some interest to you. 2014 has bit over 19 kWh usable.

http://sparkev.blogspot.com/2016/03/ran ... omial.html

Image

JoeSchmoe
Posts: 53
Joined: Sat Sep 13, 2014 10:35 pm

Re: Battery degredation

Fri Mar 04, 2016 11:55 pm

I'm at approx 7500 miles and my indicated range is 58 miles give or take. I have much sticker tires, though, and they are slightly larger than stock. I also don't drive slowly and charge to full each day. I think the range indicator is becoming more conservative, though. Meaning that by the time I reach 50% charge I have more than 29 miles of indicated range remaining. I don't pay it too much attention though, since it's well within the range I need it to be even with heater and A/C usage.

Lastly, I agree. I'm also really glad this is a lease.

NORTON
Posts: 1240
Joined: Fri May 01, 2015 5:52 am
Location: KC,MO

Re: Battery degredation

Sun Mar 06, 2016 10:24 am

DDMan11 wrote:.... today, I had 8.8 KW used at 50% battery life. This indicates I have somewhere around 17.6 KW total battery life. That is a nearly 16% battery life lost. ...
The 2014 Spark EV has a 21 kWh rated battery, but it does not use the entire capacity. No EV does that for battery life reasons.
DD, what are you using as your starting capacity?


I'm still coming to grips with this method of measuring 'degradation'.
As seen in the other thread on this subject there is a large variation on all data points and it must be plotted over time to see a trend.
My few initial attempts at gathering data shows minimal degradation. But time will tell. I need to start a spread sheet.
Used '14 2LT w/ DCFC. +71 K miles.
Mostly free charging! Only one LONG visit to the shop....
GM needs Modern Troubleshooting tools for Modern EV's.
3 step Trouble Tree, 2nd guess not covered by warranty and cost $800. 3rd guess fixed the problem.

NORTON
Posts: 1240
Joined: Fri May 01, 2015 5:52 am
Location: KC,MO

Re: Battery degredation

Sun Mar 06, 2016 11:11 am

SparkevBlogspot wrote:I don't know how diligent people "baby" their batteries or how much better it'd be to follow conventional rules, them being
......
Of course, above are not realistic for battery EV, better suited to hybrids. ....
I don't know how you would quantify the results of your diligent "baby" techniques of BEV ownership.

And I can only assume when you discuss all this with potential BEV buyers they are left with their heads spinning with more questions and worries.

What's wrong with just driving it and plugging it in when you get home? And forget about it...

Or for me, it's once a day when I get to a free public L2 across the street from where I work.
Weekends I'll swing into a DCFC, as needed, for 10-15 minutes to get close to the 80% mark (if I'm waiting) or walk away and let it top up to 100%.

It's true, 'conventional' thinking for a hybrid is to only use the pack from 20% to 80%. And the driver has no control over that.
With a BEV it makes sense to use more of the battery capacity. But 'baby' or not, will it be worth it for all the extra care and effort? Only time will tell.
Used '14 2LT w/ DCFC. +71 K miles.
Mostly free charging! Only one LONG visit to the shop....
GM needs Modern Troubleshooting tools for Modern EV's.
3 step Trouble Tree, 2nd guess not covered by warranty and cost $800. 3rd guess fixed the problem.

MrDRMorgan
Posts: 993
Joined: Wed Oct 30, 2013 7:27 am
Location: Manteca, California

Re: Battery degredation

Mon Mar 07, 2016 7:26 am

DDMan11 wrote:I've had my 2014 Spark for now a year and 8 months. The car now has 23k on the odometer but my battery life has suffered greatly. I began with 80-100 miles of range (depending on my driving style and weather), but now I'm getting 60-75 miles.

I've used the built in battery usage meter, and today, I had 8.8 KW used at 50% battery life. This indicates I have somewhere around 17.6 KW total battery life. That is a nearly 16% battery life lost. Does anyone else have this type of battery deterioration? Anyone know what Chevy's battery life warranty is, or when they will do something about excessive battery life loss? If I hit the 20% mark, I won't be able to make my daily round trip.
I have just started checking this to see if I can get a baseline reference against which to compare future measurements. My 2015 Spark EV 2LT currently has 8000 miles and 9 months of use. The other day I charged at a DCFC and let the charge continue until the charger turned itself off. I started out at 55%, ended at 100% and used 7.5 kWh. I do not know if the 7.5 kWh is what went into the battery or into the AC to DC converter in the DCFC. Regardless, it calculates too 16.67 kWh battery capacity. I will run this test a few more times to get an average value and then use that number as a reference point for evaluating any battery degradation. Note: the blue-ball guess-o-meter read 102 miles after the full charge. My best full-charge guess-o-meter number for both my 2014 and 2015 Spark EV usually is 101-106 mi in mild to warm weather. This winter I saw these numbers fall into the low 70s which is what I expected to see. If battery degradation is occurring, then I expect to see my maximum blue-ball guess-o-meter value fall year to year everything else being equal.

9 Mar 2016: I just finished my fourth full-charge DCFC session in the last 6 days for my 2015 Spark EV. The battery capacity test data was taken from the display on the same NRG eVgo DCFC station. The results look encouraging as something I can use as a baseline to determine if my battery is degrading or not. The battery capacity results for the four tests ranged from 16.48 kWh to 16.70 kWh with an average of 16.58 kWh. The percent the battery was discharged at the start of the tests ranged from 45% to 77%. The guess-o-meter reading after each full charge ranged from 97 miles to 102 miles (mi/kWh ranged from 5.3 to 5.8).
Last edited by MrDRMorgan on Wed Mar 09, 2016 1:49 pm, edited 1 time in total.

SparkevBlogspot
Posts: 499
Joined: Mon May 25, 2015 12:19 pm

Re: Battery degredation

Mon Mar 07, 2016 9:49 am

NORTON wrote:But 'baby' or not, will it be worth it for all the extra care and effort?
My point about "babying" the battery is with regard to people who complain about degradation. I completely agree, just use it as you see fit, not worry about such extremes to save the battery. Even with all that effort, it's dubious how much it'll be saved.

However, few things can be done that may (or may not) extend battery are.
1. Don't charge to 100%.
2. Don't drive too low (5%?) or "turtle" mode.
3. Keep it about 50% if not driving for a while.

I do #1, just because I live on mountain top, and I save extra for regen braking. #2, I think it's obvious unless one's in a pinch. #3 is not so obvious to people unfamiliar with Li batteries.

xylhim
Posts: 222
Joined: Wed Nov 20, 2013 7:12 pm

Re: Battery degredation

Wed Mar 09, 2016 10:14 pm

I think temperature may be a pretty big factor in determining the battery capacity as well- if temps are low, you'll likely under-estimate your capacity. I would suggest a test were you are charging at and running the vehicle at around 25 degrees C: http://batteryuniversity.com/learn/arti ... mperatures

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