Battery Degradation vs Battery Limited Warranty

Chevy Spark EV Forum

Help Support Chevy Spark EV Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

CarlinOC

Member
Joined
Oct 3, 2013
Messages
10
I have had my 2014 Spark EV since October 10, 2013. I've racked up 18,900 miles and now, like others, I am seeing my full charge range diminishing.

Up until February this year (27 months & ~17,000 miles) I was consistently fully charged for 86 miles +or- 2.

Then, I noticed I was only getting ~76 +or-2. It was not gradual decline, but rather a step down. I thought it was kind of strange that it dropped by like 10 miles rather than a mileage decline over time. But it did not really matter because the max range I need is 62 miles, So, no battery anxiety.

Now I am only fully charging to a range of 69 miles. Now I am concerned. Big difference having a cushion of 14 - 24 miles that I know I'll never use and only having 7 miles. If there is another step down, I am hosed until I can get a Bolt.

The very last thing I want to suffer is my nay sayer family members snickering "told you so".

So, has anybody contacted their dealer for details about the Battery Limited Warranty? "Spark EV battery and specific electric drive components are covered for 100,000 miles/8 years (whichever comes first). The Spark EV battery warranty covers 161 battery components in addition to the thermal management system, charging system and electric drive components. See dealer for details."

My impression is the warranty covers failure. Thus, if my battery fails to charge, say to a 1 mile range, before 100,000 miles or 8 years, I'll get a new one. But, what of the long slow agonizing decline until then? If Spark EV 2014 owners are not getting the 86 mile range charge now, maybe we should test the warranty?

My local dealer ownership just changed. Before I go in, I wanted to hear about the good, the bad and maybe the ugly, if anybody has some advice.

I really want to hang on until I can get a Bolt. but, since that is still at least 6 - 8 months away, I am wondering what I should do.
 
What is the battery capacity when measured with the following procedure?

You can estimate the battery capacity by pressing the leaf and going to the "energy details" screen with the pie chart. If your last charge was a full charge, you can add up the three percentages (Driving and Accesories, Climate Setting, and Battery Conditioning) and divide by 100 to get the fraction of the battery that has been used. This screen also has "Energy Used" in kWh. Divide the "Energy Used" by the fraction to estimate the usable battery capacity in kWh. You will probably get a more accurate number if you wait until the battery is at least 40% used. In summary here's an equation:

Code:
(battery capacity in kWh) = 100 * (Energy Used) / (Driving and Accessories + Climate Setting + Battery Conditioning)
 
CarlinOC said:
......
Up until February this year (27 months & ~17,000 miles) I was consistently fully charged for 86 miles +or- 2.

Then, I noticed I was only getting ~76 +or-2. It was not gradual decline, but rather a step down. ....

Have you tried using the 'Math Method' mentioned above to get a battery capacity number?

Are there not seasons where you live? I NEVER get 'consistent' GOM numbers.
For example: I have the slow or fast commute route, I have drastic seasonal temp changes, sometimes I only go for 80% at DCFC stations, sometimes I 'Head out on the Highway, Lookin' for Adventrue', just an old fashioned Joy Ride,, only for free!!

I see seasonal trends but rarely see the same GOM number twice.
The GOM is not meant to be a way of measuring battery capacity.

I'm at +18k miles and all is well with my battery capacity!!
 
NORTON said:
Have you tried using the 'Math Method' mentioned above to get a battery capacity number?
No, but I will so I can make some comparisons.
NORTON said:
Are there not seasons where you live? I NEVER get 'consistent' GOM numbers.
For example: I have the slow or fast commute route, I have drastic seasonal temp changes, sometimes I only go for 80% at DCFC stations, sometimes I 'Head out on the Highway, Lookin' for Adventrue', just an old fashioned Joy Ride,, only for free!!
2 seasons is Orange County, California. Sometimes cool and wet (although not much wet for the last 5 years). Sometimes hot & dry.
Only once the entire time I have driven my Spark EV did the the "Battery Conditioning" energy raise above zero percent. It was a hot day, I was about 3/4 down and %1 was displayed. Occasionally I have a good 5 -7 minute run down the local freeway, but mostly stop & go. I've made 6 trips up to L.A. (the 62 miles), charged up and come home. Even then it was not 65 all the way.
Early 2014 Spark EVs were not available with DCFC. Except for the trips to LA, I always charge at home. Up in L.A. I charge at my wife's girlfriend's house. She has an electric Ford Focus.
NORTON said:
I see seasonal trends but rarely see the same GOM number twice.
The GOM is not meant to be a way of measuring battery capacity.
Fair enough. I have been using the estimated mileage range in the blue ball on the left and the trip odometer to keep battery anxiety in check.

Until February, adding estimated miles remaining in the blue ball & the miles driven as recorded in the trip odometer have been in the mid 80's, rather consistently.

Just yesterday I started out with a full charge range of 69 miles (again). I went ~17 miles out. At my destination, the blue ball estimated 53 miles remaining range. When I got home, I had ~35 miles on my trip odometer and 33 miles in the blue ball.

This seemed to be the easiest way to measure my range rather than trying to do the "Math Method" in my head while driving to calm battery anxiety.

Perhaps recording range estimate, trip odometer, and battery capacity at destination points and home would provide the evidence needed for the dealer to do something? Whatever that something might be?

I was thinking that maybe the battery is not single solid 600 pound unit that would have to be changed, but maybe there are cells within the battery that could be replaced? The fact that I've seemed to drop in steps seems to say pieces of the battery have failed.
NORTON said:
I'm at +18k miles and all is well with my battery capacity!!
Thanks. Glad to hear all is well. As with any new technology and being early adopters, I think we will have very different experiences. I appreciate you sharing yours.
 
One thing you might check is your mi/kWh number. If that's significantly less than what was before, there may be something wrong with the car other than the battery. If that number is about the same, it could be the battery.

From a post in forum, apparently the warranty card states that warranty is to 65% of battery capacity and testing involves a day at the dealer. If you do take it to dealer for testing, please post your experience and what was involved.
 
If you haven't yet, check your tire pressure. A small drop there could be enough to explain the difference. Even if the pressure hasn't dropped, adding a couple PSI might be enough to get your range back.

Regarding the actual battery warranty, the language was a bit vague when I read it back when I got my Spark (and I'm reporting this from memory from over two years ago, so take this with a grain of salt), but my interpretation was that there was an acceptable degradation curve. If you got below that curve they'd bring you at least back up to it but not necessarily back to new condition.
 
Can you give us an update on this, I never see more than 75 miles in the blue ball
 
fox said:
Can you give us an update on this, I never see more than 75 miles in the blue ball

Here are my average monthly full-charge Blue Ball GOM numbers. We had a cold winter ( at least for Central California) where I live.

2014 Spark EV: Mar - Oct 2016: 105 miles
2015 spark EV: Mar - Oct 2016: 95 miles

2014 Spark EV: Dec - Jan 2016 / 17: 80 miles
2015 Spark EV: Dec - Jan 2016 / 17: 79 miles

2014 Spark EV: Mar 2017: 99 miles
2015 Spark EV: Mar 2017: 91 miles (fully charged last night: 98 miles)

Driving habits and use of the A/C or heater have major impact on GOM range.
 
fox said:
Can you give us an update on this, I never see more than 75 miles in the blue ball

I have a 2015 Spark EV bought new as a super-leftover at the end of Nov 2016. I live in CT and thus the car has yet to be driven under anything like ideal conditions for maximum range. I have only seen 62-74 miles of range on the GOM (except during one short winter reprieve when it read 78). I too was initially was concerned about battery capacity degradation and how its long idle period may have effected it. However, calculations of the battery capacity gave values between 17.2 and 18.0 so all appears to be well. The main reasons for my low GOM range are weather and a largely fast highway commute. One possibly surprising effect on range I found recently was due to driving highway speeds in very heavy rain. A quick Google search revealed that very wet roads apparently can increase rolling resistance by up to 40%! Therefore, if one lived in a relatively wet area your GOM could be down for that reason also.
http://www.davidpublisher.org/Public/uploads/Contribute/566e64a472e9f.pdf
I'm expecting to get some GOM readings in the range advertised by Chevy as we move further into spring.
 
Temperature makes a big difference, although I've not kept written records.

The GOM only charged up to 64 in extended cold periods, like we had in MD in December and it's hard to run without heat on when it's 20 F and the windshield is frost covered. Rain and snow take a hit. I'm bothered by not having a reversing valve to produce warm air in heatpump mode, rather than the stock resistance heat.

Last summer the GOM consistently posted over 100 for a couple of months, even in the teens once in a while. Now that it's warming up in March and April, it's posting 75 to 89, depending on whether or not the temps are cooler or warmer.

Battery technology keeps improving and is getting cheaper. My forecast is after 8 years of use, there will be low cost replacement batteries that get twice the kW in the same package.

Saturday (April 1) a fellow with a 2008 Tesla roadster was telling me about recently replacing his battery after 9 years. When new in 2008 it had 250 miles range, but with the recent new battery now charges to 345 miles. That wasn't an April Fool's story, and the batteries will continue to improve. Be nice to see our Spark batteries get to below the cited 65% level at 7-1/2 years while still under warrantee :)
 
I started keeping "performance" records again in 2016 after my post. The main thing I discovered is the "estimated remaining" plus the "actual travelled" no longer added up to 85 + / -.
Although I do not have my records from when I first got the car, previous to my post, universally the estimated remaining plus the actual travelled ALWAYS was in the 80's. Now you can see it is in the 70's.

Code:
Date      Full Charge*  Remaining*       Trip*     Total*
27-Jul     75             16             51.7      67.7
28-Jun     75             36             31.8      67.8
16-Aug     74             48             21.1      69.1
12-Aug     74             59             10.9      69.9
10-Aug     76             44             26.6      70.6
23-Jun     75             28             43.1      71.1
4-Sep      76             32             39.1      71.1
13-Sep     75             60             11.3      71.3
27-Jun     75             51             20.3      71.3
10-Sep     75             26             45.4      71.4
4-Aug      76             58             13.8      71.8
2-Sep      76             35             37.1      72.1
20-May     70             30             42.3      72.3
22-May     72             39             33.7      72.7
17-Sep     74             50             22.8      72.8
6-Aug      76             49             23.9      72.9
10-Jun     73             47             25.9      72.9
19-Aug     78             50             23.3      73.3
31-May     74             58             15.5      73.5
12-Jun     73             61             12.6      73.6
5-Jul      75             44             30.0      74.0
26-May     74             45             29.0      74.0
21-May     71             51             23.0      74.0
28-Jul     73             44             30.4      74.4
16-Jun     74             49             25.9      74.9
18-Jun     74             58             17.5      75.5
6-Jun      74             53             23.0      76.0
23-Sep     74             11             65.4      76.4
30-Jun     75             13             63.7      76.7
31-Aug     76             32             45.0      77.0
30-Jul     75             26             51.6      77.6
24-Aug     78             24             53.8      77.8
18-Aug     76             52             25.9      77.9
17-Aug     72             26             54.3      80.3
23-Aug     78             38             44.5      82.5
* = all ranges in miles

So, the bottom line is that after 2 years I lost about 10 miles of range. For the last 5 months, October 2016 - February 2017, I did not keep any records because nothing seemed to change. I kept the Spark EV until my Bolt arrived 2/7/2017. I kind of wonder if someone who may buy the Spark EV is expecting the 84 range rating the car originally had versus the actual range now of seventy something?
 
CarlinOC said:
I started keeping "performance" records again in 2016 after my post. The main thing I discovered is the "estimated remaining" plus the "actual travelled" no longer added up to 85 + / -.
Although I do not have my records from when I first got the car, previous to my post, universally the estimated remaining plus the actual travelled ALWAYS was in the 80's. Now you can see it is in the 70's.

<SNIP>

So, the bottom line is that after 2 years I lost about 10 miles of range. For the last 5 months, October 2016 - February 2017, I did not keep any records because nothing seemed to change. I kept the Spark EV until my Bolt arrived 2/7/2017. I kind of wonder if someone who may buy the Spark EV is expecting the 84 range rating the car originally had versus the actual range now of seventy something?

Could you re-post that in chronological order, rather than in range order, so that it would be easier to get a grip on what is happening? Thx.

Congrats on the Bolt. It would be interesting to hear your take on how the two compare.

FWIW, I've pushed cars. I'd much rather drive.
 
Great info!

It would be very interesting to hear your report comparing the Bolt to the Spark!

You hear that one or more of the many cells sometimes go bad in batteries. A little off topic, but a fellow with a Solar PV firm was telling me that Toyota wanted something like ~$3K to replace the battery in his dad's Prius. He said they took it out, diagnosed the few bad cells, and replaced them at a couple of hundred dollar cos. The fix got the battery was back to original capacity. Made me wonder if a similar fix would work on a Spark with a few bad cells?
 
I asked the Chevrolet Spark EV service guy about replacing cells. Said the battery is all or nothing. One unit.
Maybe, as said above, there will be a reasonably priced battery replacement that may even extend the range. (Sorta like replacing a blown engine on a car that is still worth it.)
I'd go back to a Spark in a heart beat if it got at least 170 mile range. That is all I really need.
 
QuietRider said:
Toyota wanted something like ~$3K to replace the battery in his dad's Prius. He said they took it out, diagnosed the few bad cells, and replaced them at a couple of hundred dollar cos.
Gen1 Prius pack costs about $3K, and $2.3K with core return credit. Misc parts + labor add about $1.3K for a total of $3.6K. Pack is only 100 lb, and labor should be only 2 hours. However, the new pack only comes with 1 year warranty. Should anything go wrong, yet another $3.6K down the drain. This is why I didn't replace the Prius battery, instead got SparkEV.

There are shops that do for much less, but I wouldn't trust them. One company said there were so many returns after doing low cost pack replacement that they stopped that business.

If you only replace few cells with new ones in old battery, cells will be mismatched and could have bad consequence. I have to wonder if this is why so many low-cost replacement packs were failing.

Either way, entire pack should be replaced whether that's new or good working used. Cell matching is much more important with LiIon than with NiMH.
 
I just bought a used Spark EV in March. And was also wondering about battery capacity. I can't seem to find consistent information in the actual pack size for the 2014Spark EV. Also whether GM limited the useable capacity to help preserve battery life. And whether the warranty was based on 65% of useable capacity vs 65% of actual pack size.

For example is the total pack size 21kWh with a 10% buffer? And therefore a useable capacity of closer to 19kWh?

If the warranty is based on 65% of 21kWh, that puts the warranty not kicking in until battery capacity drops to close to 13.65kWh.
 
CypressVH said:
<snip>
For example is the total pack size 21kWh with a 10% buffer? And therefore a useable capacity of closer to 19kWh?

If the warranty is based on 65% of 21kWh, that puts the warranty not kicking in until battery capacity drops to close to 13.65kWh.
You are right about the useable capacity being close to 19kWh. I was 18 point something when I had about 4 miles left. That was the closest I got to 0 miles left.

Basically, estimated remaining plus miles driven was pretty consistent for range. Either in the mid 80's or mid 70's later on.

The average of 4.4 miles per kWh was also relatively consistent thus 19 kWh x 4.4 = 83.6 which is the 84 miles total range spec. So, 4.4 x 13.65 puts minimum warranty range at 60. If full charge range and estimated range + miles driven both go below 60 miles, then you may have a warranty claim before 2024 (10 year warranty). If you are not planning to go more than 60 miles before the next charge, does it matter? I discovered only once in 3 years did I go more than 75+ miles in a single trip. All others were well within even the mid 70 range. The Spark EV is a GREAT urban runabout.

What is your Spark EV showing as full charge range?
 
CarlinOC said:
You are right about the useable capacity being close to 19kWh. I was 18 point something when I had about 4 miles left. That was the closest I got to 0 miles left.

Basically, estimated remaining plus miles driven was pretty consistent for range. Either in the mid 80's or mid 70's later on.

The average of 4.4 miles per kWh was also relatively consistent thus 19 kWh x 4.4 = 83.6 which is the 84 miles total range spec. So, 4.4 x 13.65 puts minimum warranty range at 60. If full charge range and estimated range + miles driven both go below 60 miles, then you may have a warranty claim before 2024 (10 year warranty). If you are not planning to go more than 60 miles before the next charge, does it matter? I discovered only once in 3 years did I go more than 75+ miles in a single trip. All others were well within even the mid 70 range. The Spark EV is a GREAT urban runabout.

What is your Spark EV showing as full charge range?

When I first bought it it was showing ~60-65miles. But it was an Oregon car and the middle of winter. The average miles/kWh was something like 3.3miles. With some conservative driving and improved weather, I did some range estimates closer to 75-80miles.

70miles would just about get me to the airport and back (with about 2 miles left). But the need to go down and back to the AP is once or twice a year. But a couple times a week I need 65.5 miles or so round trip. Fortunately on those days I do have access to chargers during the day, if it seems I'm not going to make it. (Weather, etc).
 
As an update: once summer came the GOM Started showing 86miles estimated range or so. Then when fall and winter hit is was back down to 58-65 or so (but having to use the heater and windshield defrost a fair bit really takes a hit on the range, too.
As the weather is warming back up, the range is creeping back up again.
 
The amount a Spark EV battery degrades is always good for a discussion. After trying many different ways to see what is going on, I finally determined that I get my most uniform results by fully charging the battery overnight, resetting the trip meter to zero, and driving the car normally for 50 to 60 miles; even if it takes multiple trips over a number of days. Then I go to the Energy Information screen and record the % Used and the kWh used. Then I divide the kWh used by the %(decimal value) used to get the calculated battery capacity.

Here are my average results for recordings made from December thru today:

2014 Spark EV 13663 miles on the ODO 16 data points Calculated Battery Capacity = 17.1 kWh
2015 Spark EV 26508 miles on the ODO 25 data points Calculated Battery Capacity = 16.0 kWh
2016 Spark EV 9496 miles on the ODO 24 data points Calculated Battery Capacity = 17.3 kWh

If you are into statistics: one standard deviation for both the 2014 and 2016 Spark EVs is 0.3 kWh. One standard deviation for the 2015 Spark EV is 0.4 kWh.

Once you get a feel for your battery capacity, you can multiply your mi/kWh number on the trip meter by your calculated battery capacity to get an idea of your expected range. So far, I have seen the battery in my 2015 Spark EV has degraded the most; but it also has the most miles on the ODO.

Right now, for my 2015, I am seeing 5.5 - 6.0 mi/kWh on the trip meter. 5.5 mi/kWh x 16.0 kWh gives me an expected GOM full-charge range of 88 miles. I am seeing 89-92 miles on the GOM after a full overnight L2 charge. During the winter my mi/kWh values drop significantly as expected and the full-charge GOM value drops too.
 
Back
Top