Page 15 of 17

Re: Battery degredation

Posted: Wed May 08, 2019 1:02 pm
by scrambler
Thanks,
I find that if I note numbers when they change together, I can get minimal fluctuation.

But the loss of capacity on our 2014 is a straight downward line that shows no sign of slowing down.
Over the last two years, it has been declining 0.15 kWh per 1,000 miles going from 15.8 kWh at 52,000 miles, down to 13.7 kWh at 66,000 miles.
If I assume the nominal usable capacity of 18.4 kWh that means the battery lost 25.4 %
If I assume the nominal usable capacity of 19 kWh that means the battery lost 27.7 %

Given I do about 7,000 miles a year with that car, I loose about 1.05 kWh per year, so I should cross the 35% degradation before 8 years and 100k miles.

It will be interesting to see how that goes with GM :)

Re: Battery degredation

Posted: Wed May 08, 2019 1:38 pm
by MrDRMorgan
scrambler wrote: Thanks,
I find that if I note numbers when they change together, I can get minimal fluctuation.

But the loss of capacity on our 2014 is a straight downward line that shows no sign of slowing down.
Over the last two years, it has been declining 0.15 kWh per 1,000 miles going from 15.8 kWh at 52,000 miles, down to 13.7 kWh at 66,000 miles.
If I assume the nominal usable capacity of 18.4 kWh that means the battery lost 25.4 %
If I assume the nominal usable capacity of 19 kWh that means the battery lost 27.7 %

Given I do about 7,000 miles a year with that car, I loose about 1.05 kWh per year, so I should cross the 35% degradation before 8 years and 100k miles.

It will be interesting to see how that goes with GM :)
scrambler wrote:
Wed May 08, 2019 1:02 pm
Thanks,
I find that if I note numbers when they change together, I can get minimal fluctuation.

But the loss of capacity on our 2014 is a straight downward line that shows no sign of slowing down.
Over the last two years, it has been declining 0.15 kWh per 1,000 miles going from 15.8 kWh at 52,000 miles, down to 13.7 kWh at 66,000 miles.
If I assume the nominal usable capacity of 18.4 kWh that means the battery lost 25.4 %
If I assume the nominal usable capacity of 19 kWh that means the battery lost 27.7 %

Given I do about 7,000 miles a year with that car, I loose about 1.05 kWh per year, so I should cross the 35% degradation before 8 years and 100k miles.

It will be interesting to see how that goes with GM :)
Now for the fun part. The 2014 Spark EV Limited Warranty and Owner Assistance Information booklet states on page 14:

"If warranty repair requires replacement, the high voltage battery may be replaced with either a new battery or factory reconditioned high voltage battery with an energy capacity (kWh storage) level at or within approximately 10% of that of the original battery at the time of warranty repair.
Your Electric Propulsion battery warranty replacement may not return you vehicle to an "as new" condition, but it will make your Spark EV fully operational appropriate to its age and mileage." :o

Re: Battery degredation

Posted: Tue May 14, 2019 2:48 pm
by fizzit
My 2015 with 44300 miles is now down to 13.7 KWh. I brought it in to the dealership last month to see if there was anything wrong. They kept it for a couple weeks but couldn't find anything aside from the A/C being slightly overcharged. When I bought the car last September it was at about 40100 miles and 14.8 KWh, and degradation actually appears to be speeding up so it should be at 35% capacity loss by next August. It's still a fun car but it'll be nice to get a new battery with full range.

Re: Battery degredation

Posted: Wed May 15, 2019 8:54 am
by MrDRMorgan
fizzit wrote:
Tue May 14, 2019 2:48 pm
My 2015 with 44300 miles is now down to 13.7 KWh. I brought it in to the dealership last month to see if there was anything wrong. They kept it for a couple weeks but couldn't find anything aside from the A/C being slightly overcharged. When I bought the car last September it was at about 40100 miles and 14.8 KWh, and degradation actually appears to be speeding up so it should be at 35% capacity loss by next August. It's still a fun car but it'll be nice to get a new battery with full range.
I really find this interesting. Do you charge to 100% each time you charge and what type of charging do you mainly use - L1, L2 or DCFC? So far, the HV battery degradation rate in my 2016 Spark EV is about 1 kWh every 4000 miles. You lost 1.1 kWh in 4200 miles which equates to 1.02 kWh per 4000 miles. I believe both the 2015 and 2016 Spark EVs use the same HV battery. Also, for 2015 and 2016 Spark EVs, you will need to have 40% or more battery degradation. 35% was for 2014 Spark EVs.

While the battery degradation is a bit concerning, I am still seeing full-charge GOM (blue ball) values in the mid to high 90s for both my 2014 Spark EV and my 2016 Spark EV. And.. my wife and I are having a ball driving both of these little cars. I hope someone will eventually be able to rebuild the battery pack so Sparky can run forever! :D

Re: Battery degredation

Posted: Fri May 17, 2019 9:33 am
by fizzit
MrDRMorgan wrote:
Wed May 15, 2019 8:54 am
I really find this interesting. Do you charge to 100% each time you charge and what type of charging do you mainly use - L1, L2 or DCFC? So far, the HV battery degradation rate in my 2016 Spark EV is about 1 kWh every 4000 miles. You lost 1.1 kWh in 4200 miles which equates to 1.02 kWh per 4000 miles. I believe both the 2015 and 2016 Spark EVs use the same HV battery. Also, for 2015 and 2016 Spark EVs, you will need to have 40% or more battery degradation. 35% was for 2014 Spark EVs.

While the battery degradation is a bit concerning, I am still seeing full-charge GOM (blue ball) values in the mid to high 90s for both my 2014 Spark EV and my 2016 Spark EV. And.. my wife and I are having a ball driving both of these little cars. I hope someone will eventually be able to rebuild the battery pack so Sparky can run forever! :D
I do charge to 100%, and I pretty much always use L2 with the occasional L1.

Yup, the '14 uses A123 and they moved to LG chem in 2015. My warranty booklet says 35%, hopefully that's not a typo. And I think the degradation might actually be more time-based rather than mileage. The rate of degradation per mile is wildly different between before I purchased it (-.0005%/mile) and during my ownership (-.0014%/mile) but pretty much the same degradation per day - .017%/day before I owned it and .02%/day during my ownership.

Re: Battery degredation

Posted: Sat May 18, 2019 9:12 am
by MrDRMorgan
fizzit wrote:
Fri May 17, 2019 9:33 am
MrDRMorgan wrote:
Wed May 15, 2019 8:54 am
I really find this interesting. Do you charge to 100% each time you charge and what type of charging do you mainly use - L1, L2 or DCFC? So far, the HV battery degradation rate in my 2016 Spark EV is about 1 kWh every 4000 miles. You lost 1.1 kWh in 4200 miles which equates to 1.02 kWh per 4000 miles. I believe both the 2015 and 2016 Spark EVs use the same HV battery. Also, for 2015 and 2016 Spark EVs, you will need to have 40% or more battery degradation. 35% was for 2014 Spark EVs.

While the battery degradation is a bit concerning, I am still seeing full-charge GOM (blue ball) values in the mid to high 90s for both my 2014 Spark EV and my 2016 Spark EV. And.. my wife and I are having a ball driving both of these little cars. I hope someone will eventually be able to rebuild the battery pack so Sparky can run forever! :D
I do charge to 100%, and I pretty much always use L2 with the occasional L1.

Yup, the '14 uses A123 and they moved to LG chem in 2015. My warranty booklet says 35%, hopefully that's not a typo. And I think the degradation might actually be more time-based rather than mileage. The rate of degradation per mile is wildly different between before I purchased it (-.0005%/mile) and during my ownership (-.0014%/mile) but pretty much the same degradation per day - .017%/day before I owned it and .02%/day during my ownership.
I believe you are correct - I had it backwards.. The HV battery degradation warranty point for the 2014 and 2015 Spark EVs is 35%. It was raised to 40% for 2016. I would like to hear what the current HV battery capacity is for "high mileage" Spark EVs of each model year - especially those over 100K miles.

Re: Battery degredation

Posted: Sat May 18, 2019 11:10 am
by TheLondonBroiler
fizzit wrote:
Fri May 17, 2019 9:33 am
My warranty booklet says 35%, hopefully that's not a typo.
Any chance you'd post a picture of the front of your warranty manual and where it says 35%? I can not for the life of me find any specific battery degradation warranty info on the web regarding the 2015, and I bought mine second hand (no manuals included, naturally).

This thread sure got busy. I've only driven my Spark once in the past two months, but I've put 6k miles on my Bolt :)

Re: Battery degredation

Posted: Sat May 18, 2019 12:18 pm
by MrDRMorgan
TheLondonBroiler wrote:
Sat May 18, 2019 11:10 am
fizzit wrote:
Fri May 17, 2019 9:33 am
My warranty booklet says 35%, hopefully that's not a typo.
Any chance you'd post a picture of the front of your warranty manual and where it says 35%? I can not for the life of me find any specific battery degradation warranty info on the web regarding the 2015, and I bought mine second hand (no manuals included, naturally).

This thread sure got busy. I've only driven my Spark once in the past two months, but I've put 6k miles on my Bolt :)
I no longer have the 2015 Spark EV but some of the notes I posted months ago suggest the limit WAS 35%. I too searched the web for the "2015 Chevrolet spark EV limited warranty and owner assistance information" booklet but could no longer find it. Perhaps some other owner of a 2015 Spark EV has it and can copy it. I know it reads just like the booklet for the 2016 Spark EV except the 2016 limit is 40% while the limit for the 2015 Spark EV was 35%. Your Chevy dealer should be able to confirm this for you.

Re: Battery degredation

Posted: Sun May 19, 2019 9:20 am
by Engineear
A little off topic perhaps...I had been charging to 92-94 miles at 8 ohms on my home EVSE. Last week I checked to see if there were any outstanding recalls on my car and come to find out the Powertrain Control Module 2 needed reprogramming to correct the range estimation. So, the last 2 charges netted me 81 and 82 miles. Not sure what to think of that. How do I know the 92 number was wrong? In any event I'll see how long these numbers stay level before a drop from degradation. Approaching 17000 miles on the 2015. Other than that the car is great. The only thing I'd change would be different shocks, though from what I've read, that's unlikely, and non staggered tires to add a bit more cornering traction. Not complaining, just dreaming. Car is quick!!

Re: Battery degredation

Posted: Sun May 19, 2019 12:40 pm
by MrDRMorgan
Engineear wrote:
Sun May 19, 2019 9:20 am
A little off topic perhaps...I had been charging to 92-94 miles at 8 ohms on my home EVSE. Last week I checked to see if there were any outstanding recalls on my car and come to find out the Powertrain Control Module 2 needed reprogramming to correct the range estimation. So, the last 2 charges netted me 81 and 82 miles. Not sure what to think of that. How do I know the 92 number was wrong? In any event I'll see how long these numbers stay level before a drop from degradation. Approaching 17000 miles on the 2015. Other than that the car is great. The only thing I'd change would be different shocks, though from what I've read, that's unlikely, and non staggered tires to add a bit more cornering traction. Not complaining, just dreaming. Car is quick!!
Without knowing what you are seeing for mi/kWh, I would guess your battery capacity is between 17 and 18 kWh. My leased 2015 had a "calculated" battery capacity of about 17.4 kWh at 17K miles. But, the best way to find out is to measure it using TorquePro and a good OBD2 device. Otherwise, you can use the data on the Energy Information screen to get a ballpark estimate.