Hey Guest, welcome to ChevyBolt.org. We encourage you to register to engage in conversations about your Bolt.

6-7% Battery Degredation in 6 Months?

2555 Views 34 Replies 9 Participants Last post by GJETSON, 8 mo ago

Bolticus

Discussion Starter · 8 mo ago

Hello,

I have a 2017 Bolt that had the battery replaced on April 1st of this year. At that time, Torque Pro showed the battery capacity at 65 kWh. Also, I have my own ways of calculating battery capacity and I was getting about the same number. I can get into those methods if anyone is interested.

Well I took a 150 mile drive and did a little math on what the Bolt reported as my efficiency (Mi/kWh) and it showed I had a capacity of about 60 kWh. When I got home, I looked at Torque Pro and it now shows my battery with a capacity of 60.9 kWh! And my new battery is only 6 months old.

I have been babying the new battery keeping it at about 40% when parked. While the temps here have gone into the high 80's during the summer, nothing too terrible. It has been on a fast charger only once and even then, only about for 40 minutes. Mostly the car has been lightly driven.

This amount of degradation on my brand new battery seems excessive to me. Has anyone else experienced this? Is this normal?

Thanks!

1 - 20 of 35 Posts

Voldar

· #2 · 8 mo ago

No, it's not normal and at the same time, I am not sure your numbers are correct.
If you really want to know where you are with the battery, charge it to full and drive it to zero. Or as close to 0% SOC as you have the guts to do it. Then register the number (kWh used) and do it again.. and again, about 10 times. At the end of these tests, you'll have a vague idea where you are with the battery status.

GJETSON

· #3 · 8 mo ago

Bolticus said:
This amount of degradation on my brand new battery seems excessive to me. Has anyone else experienced this? Is this normal?

I don't believe you are seeing degradation. I believe your battery had the capacity reset to 194.3 Ah when the new battery was installed. Over time, the BMS looks at real data and adjusts the capacity to what it actually is. As I have said before, many of the new batteries are 60-62 kWh, not the 64 kWh on the label, nor the 65 kWh GM advertises.

I wish I had your problem!

www.chevybolt.org

Replacement pack more efficient?

I'm kind of OCD regarding data and have been tracking my '19 Bolt's efficiency since new. I had the pack replaced in June and have seen a significant improvement in Miles per kWh. Not sure if it is related to any software updates or less internal resistance in the pack, but am wondering if...

www.chevybolt.org

www.chevybolt.org

Reactions: 3

Bolticus

Discussion Starter · #4 · 8 mo ago

Voldar said:
No, it's not normal and at the same time, I am not sure your numbers are correct.
If you really want to know where you are with the battery, charge it to full and drive it to zero. Or as close to 0% SOC as you have the guts to do it. Then register the number (kWh used) and do it again.. and again, about 10 times. At the end of these tests, you'll have a vague idea where you are with the battery status.

Thank you for that response. I got the 60 kWh number not from just Torque Pro (and I know this is an estimate but can it be that far off?), but also by charging the car to 100%, driving it 180 miles and then noting the kWh used on the home screen and dividing that by the amount of charge used (as reported in Torque Pro and in the MyChevy App). All numbers point to a little over 60 kWhs for capacity. I hesitate on the driving from 100% to 0% as that is a bit hard on the battery. I could do my same test and drive to over 200 miles, but I am pretty confident Ill see something pretty similar.

If I do the test I will report back what I see. Thanks Voldar.

Reactions: 1

Bolticus

Discussion Starter · #5 · 8 mo ago

GJETSON said:
I don't believe you are seeing degradation. I believe your battery had the capacity reset to 194.3 Ah when the new battery was installed. Over time, the BMS looks at real data and adjusts the capacity to what it actually is. As I have said before, many of the new batteries are 60-62 kWh, not the 64 kWh on the label, nor the 65 kWh GM advertises.

I wish I had your problem!

Replacement pack more efficient?

I'm kind of OCD regarding data and have been tracking my '19 Bolt's efficiency since new. I had the pack replaced in June and have seen a significant improvement in Miles per kWh. Not sure if it is related to any software updates or less internal resistance in the pack, but am wondering if...

www.chevybolt.org

Hmmmm... I think you may be on to something. Torque Pro reports I have 190.20 Ah raw battery capacity. What is the voltage used to convert this to kWh? This (Chevy Bolt High Voltage Battery) says it is 344v but that can't be right or the initial setting of 194.3 Ah would have represented almost 67 kWh of capacity.

If you are correct, I have lost an initial 2% which isn't too bad as I have heard Li-ion batteries do have an initial steeper degradation drop in the first year. What is weird is that initially, my math using the efficiency numbers the Bolt was reporting showed a 65 kWh battery.

Do you know why many of the new batteries are delivering less than the sticker rating?

Thanks for your help in this.

Reactions: 1

GJETSON

· #6 · 8 mo ago

Bolticus said:
Thank you for that response. I got the 60 kWh number not from just Torque Pro (and I know this is an estimate but can it be that far off?), but also by charging the car to 100%, driving it 180 miles and then noting the kWh used on the home screen and dividing that by the amount of charge used (as reported in Torque Pro and in the MyChevy App). All numbers point to a little over 60 kWhs for capacity. I hesitate on the driving from 100% to 0% as that is a bit hard on the battery. I could do my same test and drive to over 200 miles, but I am pretty confident Ill see something pretty similar.

Your range test method is valid, although the lower you can go the better for accuracy. I wouldn't hesitate to go to 15%/ 3 orange bars. Do you have the Ah PID loaded up? That is the official GM PID used for warranty claims.

Rectangle Font Parallel Screenshot Number

Again, you may not be happy with 60-62 kWh of usable capacity, but that is the reality for many owners of Bolts with the the new battery chemistry. This includes brand new 2022 Bolts

See less See more

Reactions: 1

GJETSON

· #7 · 8 mo ago

The quality of these packs is all over the map. Many/most? are seeing 60-62 kWh. Some of us have won the lottery!

www.chevybolt.org

ODB-II and iOS app

Today I did the unthinkable, I plugged an ODB-II reader into my Bolt EV. The OBD-II is LELINK and the application is EngineLink. The app is looking like this : And the info I am interested in is : I imported the PID from Bolt EV PIDs

www.chevybolt.org

www.chevybolt.org

GJETSON

· #8 · 8 mo ago

Bolticus said:
Torque Pro reports I have 190.20 Ah raw battery capacity. What is the voltage used to convert this to kWh?

Do you know why many of the new batteries are delivering less than the sticker rating?

The voltage they use can be inferred by converting kWh to Wh, and dividing by the Ah. You end up with about 320 volts with the new packs. This would say your Ah reading was ~203 Ah when you first looked at Torque Pro. The link I posted above was for a Bolt that, after three months with a new battery, was reading 202.47 Ah, and 67.45 kWh.

Only anecdotally from this and other forums, but that reading suggest mostt are closer to 60-62 kWh. I am pretty obsessive about this car and spend way too much time reading this stuff.

Reactions: 1

Voldar

· #9 · 8 mo ago

GJETSON said:
The quality of these packs is all over the map. Many/most? are seeing 60-62 kWh. Some of us have won the lottery!

ODB-II and iOS app

Today I did the unthinkable, I plugged an ODB-II reader into my Bolt EV. The OBD-II is LELINK and the application is EngineLink. The app is looking like this : And the info I am interested in is : I imported the PID from Bolt EV PIDs

www.chevybolt.org

Or maybe the technician who worked on my Bolt EV knew his deal, while the ones that are in US dealerships are just noobs.

Voldar

· #10 · 8 mo ago (Edited)

GJETSON said:
The link I posted above was for a Bolt that, after three months with a new battery, was reading 202.47 Ah, and ~~67.45~~ kWh.

64.79 kWh
I wish it was 67.45 kWh though

Just took another reading right now

Product Rectangle Font Line Material property

See less See more

Reactions: 2

Bolticus

Discussion Starter · #11 · 8 mo ago

GJETSON said:
The voltage they use can be inferred by converting kWh to Wh, and dividing by the Ah. You end up with about 320 volts with the new packs. This would say your Ah reading was ~203 Ah when you first looked at Torque Pro. The link I posted above was for a Bolt that, after three months with a new battery, was reading 202.47 Ah, and 67.45 kWh.

Only anecdotally from this and other forums, but that reading suggest mostt are closer to 60-62 kWh. I am pretty obsessive about this car and spend way too much time reading this stuff.

Well I am jealous of the Bolt that shows 202.47 Ah after 3 months. But you are saying that they put in a guess to the Ah and the system then adjusts it? So my initial raw capacity of 203 Ah was not really what the battery could hold and it was really more like the 190Ah it is now reporting, correct?

I'm happy with the 60-61 kWh of capacity as long as it degrade too much.... well more than the estimated 2% per year.

GJETSON

· #12 · 8 mo ago

Bolticus said:
Well I am jealous of the Bolt that shows 202.47 Ah after 3 months. But you are saying that they put in a guess to the Ah and the system then adjusts it? So my initial raw capacity of 203 Ah was not really what the battery could hold and it was really more like the 190Ah it is now reporting, correct?

I'm happy with the 60-61 kWh of capacity as long as it degrade too much.... well more than the estimated 2% per year.

How long after they replaced the pack did you take that first Torque Pro reading. Was it on the dealer's lot, after driving home, a week of driving?

GJETSON

· #13 · 8 mo ago

Voldar said:
64.79 kWh
I wish it was 67.45 kWh though

I know what I meant. I just didn't write what I meant.

Reactions: 1

Voldar

· #14 · 8 mo ago

GJETSON said:
I know what I meant. I just didn't write what I meant.

It happens to me too... the fingers don't follow the mind. They act like they live in democracy (doing whatever they want).
I am soo old !!!

Reactions: 1

Dark-Fx

· #15 · 8 mo ago

New batteries degrade the fastest.

Bolticus

Discussion Starter · #16 · 8 mo ago

GJETSON said:
How long after they replaced the pack did you take that first Torque Pro reading. Was it on the dealer's lot, after driving home, a week of driving?

I took it pretty much after I got it home from the dealer. But I did not note the Ah reading, just what Torque Pro thought the capacity was (65 kWh).

Reactions: 1

GJETSON

· #17 · 8 mo ago

Bolticus said:
I took it pretty much after I got it home from the dealer. But I did not note the Ah reading, just what Torque Pro thought the capacity was (65 kWh).

OK. I wanted to know, because if I end up having to take our Bolt off the dealer's lot, with the old 162.7 Ah reading still in its brain, if it hasn't flipped to the programmed default number by the time we drive the 25 miles home, I will be turning around and taking it back, and getting a rental again.

GJETSON

· #18 · 8 mo ago

Voldar said:
Just took another reading right now
View attachment 47485

I want to ask you the same question. Did you check the capacity on the dealer's lot, or when you got home, or when? I ask because, if the world made sense, all of the new batteries would be reprogrammed to read 143.25 Ah at the dealership, like it says in the manual. It might change ten minutes later, based on some algorithm, but it should start out at 143.25 Ah, right?

Rectangle Font Parallel Screenshot Number

See less See more

Reactions: 1

Voldar

· #19 · 8 mo ago (Edited)

Dark-Fx said:
New batteries degrade the fastest.

And you say this based on … ???

Voldar

· #20 · 8 mo ago

GJETSON said:
I want to ask you the same question. Did you check the capacity on the dealer's lot, or when you got home, or when? I ask because, if the world made sense, all of the new batteries would be reprogrammed to read 143.25 Ah at the dealership, like it says in the manual. It might change ten minutes later, based on some algorithm, but it should start out at 143.25 Ah, right?

View attachment 47490

As I mentioned in the thread I started, the first readings I took were about 6 months after the battery replacement. I had my battery replaced in 12/16/2021 and the first reading was taken in 06/06/2022, when I posted the first comment on the thread you posted above. I never used the ODB II reader before, in 3 years of ownership.

1 - 20 of 35 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.