My 2018 got its battery replaced in 7/2023. I bought it 10/2/2023 and I've since put about 12,500 miles on it myself, plus possibly some additional miles prior to me purchasing, but my battery is currently reporting as 188.3 Ah on my Launch X431. Not sure if that is the same as the Raw capacity PID in Torque or not but I have not been able to get the Torque PID's to work for some reason.

Unless I need to go for longer drives, my car is almost always between 40 and 60% SOC. If I go for a longer drive I generally only charge up to 80 or 85% SOC and down to 20-25% or so. Even the few times I have let it charge up higher I had my hill top reserve mode on so it stopped at 93% or whatever. My car has never been DCFC'd because every time I've tried the station has been out of service or the cables cut. So its only ever seen max 7kW level 2 charging.

 

Very nice write-up Paul. Thanks for taking the time and effort to put that all together.

I've had 3 Volts and 3 Bolts. Two of the Volts were driven over 100,000 miles, always charged to 100% every day. While I didn't keep records, I never noticed any loss in range other than the usual seasonal variations. (I also live in Bakersfield, by the way.) The third made it to 75,000 miles with no noticeable battery degradation. My first Bolt was a 2019, and for the first two years, I charged to 100% daily. Again, never noticed any degradation. I started charging it to no more than 90% after the battery fire fiasco. It only had the new battery for a few months until I traded it, along with the last Volt, for two 2023 Bolt EV 2LTs.

Now, we charge those to 90% daily unless going on a long trip, when we'll bring them up to 100% just before leaving. According to Recurrent Auto data, both the 23s are well above the average range for the battery age and mileage. So, I'm just going to keep doing the same thing and not worry about it. I think the cars will fall apart before any battery degradation becomes an issue.

 

Very nice write-up Paul. Thanks for taking the time and effort to put that all together.

I've had 3 Volts and 3 Bolts. Two of the Volts were driven over 100,000 miles, always charged to 100% every day. While I didn't keep records, I never noticed any loss in range other than the usual seasonal variations. (I also live in Bakersfield, by the way.) The third made it to 75,000 miles with no noticeable battery degradation. My first Bolt was a 2019, and for the first two years, I charged to 100% daily. Again, never noticed any degradation. I started charging it to no more than 90% after the battery fire fiasco. It only had the new battery for a few months until I traded it, along with the last Volt, for two 2023 Bolt EV 2LTs.

Now, we charge those to 90% daily unless going on a long trip, when we'll bring them up to 100% just before leaving. According to Recurrent Auto data, both the 23s are well above the average range for the battery age and mileage. So, I'm just going to keep doing the same thing and not worry about it. I think the cars will fall apart before any battery degradation becomes an issue.

Yeah, if I wasn't such a nerd I'd just drive it and forget about it. But I get a lot questions about "well how long will that expensive battery last" so I am prepped to answer that question authoritatively. My brother bought a Bolt and he just drives it. "Fills it to full" when needed and that's it.

Surprising number of Bolts in Bakersfield. Of course Teslas are on every corner.

Paul

 

Do you have longer term data from your previous battery or other cars? While a 5% loss over 20K miles doesn't sound bad, if it remains linear, then a 25% loss over 100K miles is really bad.

 

Lithium batteries never have a linear degradation curve from cradle to grave (except maybe the Leaf because Nissan didn’t care to add cooling). The reason for the sudden drop in the first year is lithium ions “stick” in the weaker structure joints of the separator and thus the battery can no longer pass charged lithium ions between the cathode and anode in that section. It will then level out and become linear until the separator reaches the end of its useful life, ions stick all over and it can no longer hold a (meaningful) charge. I’m greatly simplifying due to time, but that’s the gist as someone who worked in a battery lab.

This is why we see older Model Ss on original packs maintaining 80-85% SOH after 400k miles. The separators are pretty robust except when it comes to heat. This is also why we see no meaningful difference between cars exclusively slow (AC) charged and fast (DC) charged so long as the battery has a well-controlled environment as far as temp (Bolt, Teslas, etc all have liquid cooled packs and never let the batteries get to a point where they can be damaged).

Your phone is a great example to use. My iPhone hit 92% SOH in the first year but now, nearing the end of the second year, I’m still at 88%.

 

I’ve been keeping my iPhone 12 pretty religiously between 40 and 70. I work close to a charger most of my day so it’s not difficult. My battery health is still 96% after 500+ cycles

 

I’ve tracked battery degradation in the EVs we’ve driven during the past decade. The short answer is that our Nissan Leaf lost a lot, our Chevy Bolts not so much.

Paul: 5.7 Earthquake near Bakersfield; Let us know how you are doing, when you can!

 

A book on my display case fell over. That was the extent, plus a good ride on the bed.

Quake was very near the epicenter of the great 1952 quake that leveled Tehachapi and killed people in Bakersfield.

Stay tuned. The White Wolf Fault is a major fault and it likely intersects with the Kern River Fault. If that breaks again, it could do real damage.

Paul

 

Whenever there's a 'quake nearer than 250 miles to me, I change the reserve on my solar PV batteries from 25% to 75% (for a week), charge the cars, and make sure the phones are charged up.

The odds of a more massive follow-on 'quake are much higher.

Just ask Lucy.

 

Good news, then! I got the alert on my iPhone and jumped out of my recliner that is next to a large bookcase!

 

Thank you for this write up. I am also in Bakersfield and my wife and I both have bolts, hers is a 2020 and I have a 2022. Anyway, my tracking hasn't been as extensive as yours, but I drive quite a bit, got my bolt 12/5/23 and put 16.5k miles on it so far. I've noticed that ABRP and the EngineLink with the uploaded PIDs assume 320v to get to the estimated capacity. But I've taken my car from 100 to 2-3% a few times in both winter and spring and beaten the estimated capacity by a bit, so I'm glad you're looking at the raw Ahs, it's pretty helpful. The last time I took it from 100-2% in April I used a little over 61.2kWh based on my energy screen while the OBD apps both said I had a capacity of 57.7 kWh. It'll be interesting to see what the degradation looks like over the course of a few hot summers.

 

Good solid tip Greg. Thanks. Hadn't given it much thought, but now I will.

Paul

 

Back in my pre-EV days, I'd go to the gas station and fill up the cars and gas cans.

Never needed it, but I'd rather have it and not need it, than need it and not have it...

 

I’ve tracked battery degradation in the EVs we’ve driven during the past decade. The short answer is that our Nissan Leaf lost a lot, our Chevy Bolts not so much.

I keep detailed logs of our EVs. Beginning with a Nissan Leaf through two Chevy Bolts, I’ve recorded more than a dozen different parameters each time the car is charged. I do this so I can authoritatively answer questions from newbies to EVs and those considering an EV what kind of battery degradation they can expect.

Our 2015 Leaf suffered serious battery degradation in the heat of Bakersfield, California summers where temperatures above 110 F (44 C) are not uncommon. Consequently, the car’s limited range was reduced even further after three years. The Leaf lost 17% of its capacity in only 17,000 miles of travel, leaving us with a piddly 19 kWh when we returned the car to Nissan.

Since switching to the Bolts, we’ve traveled nearly 70,000 miles on three different batteries. Each battery has lost about 5% of its capacity over 20,000 to 30,000 miles. Importantly, this modest capacity loss hasn’t affected how we use the cars or how far we can drive them.

Disclosure: I worked for GM’s Delco-Remy Division 1968-1970 as a cooperative engineering student. I was a member of UAW Local 1981 until the National Writers Union left the UAW in May 2020. The Chevy Bolt is assembled by UAW Local 5960.

Nevertheless, I continue to track the Bolt’s performance. I enter the data on a paper record and then later enter the data into a spreadsheet.

90% of my charging is done at home, and I always charge to 100% when I am not on the road. My reasoning is that most EV drivers will do likewise. Most people will not make any effort to extend the battery’s life. Instead, they will treat the EV much the same as the gasser they replaced it with. They’ll simply “fill it up” and that’s what I am trying to replicate.

Here’s a list of the previous articles I’ve written on this topic.

• Slight Chevy Bolt Traction Battery Degradation after Nearly 30,000 Miles
• Battery Degradation 2020 Bolt Relative to 2017 Bolt EV
• Our Bolt is back with a New Pack—In Limbo No More
• Capacity of 2020 Chevy Bolt with New 2022 Battery after 6500 Miles
• Capacity of 2020 Chevy Bolt with New Battery after 11,500 Miles

After 20,000 miles on the new battery, Torque Pro is showing Bat Cap Est of 56.5 kWh and Bat Cap Raw Ah of 176.6 following the last charge. Since newly installed the battery’s Ah capacity has declined 9%. The calculated capacity has declined about 5%.
In this version of the chart, I’ve dropped the Bat Cap Est as it’s determined directly by the Raw Ah capacity. This has eliminated some of clutter in the chart making the trends easier to see.

What’s noteworthy is that the calculated capacity has only declined 5%. The calculated capacity is what we use to actually drive the car. That’s the number of kWh the car believes it has to work with.

Percent Used Method to Calculate Battery Capacity
We can infer battery capacity by knowing how much of the battery was used for so many kWh consumed between full charges. For example, if on a full charge, we consumed 31.2 kWh and arrived home with 45.9% State-of-Charge. The battery’s calculated capacity is 57.7 kWh.

31.2 kWh/(1-0.459) = 57.7 kWh

This is the battery’s calculated capacity remaining. It’s a good measure of how much battery capacity you have to work with. As noted above, the calculated battery capacity has declined about 5% over 20,000 miles.

After 20,000 miles, the new battery has approximately 60 kWh of usable capacity. The average efficiency of the Bolt during this period is 4.3 kWh/mile. The remaining usable capacity at the average efficiency I’ve measured provides an approximate range of 258 miles after 20,000 miles of use. This is roughly comparable to the EPA estimated range of 259 miles when the battery was new.

Note that there's a typo in the text. It's not 4.3 kWh/mile but 4.3 miles/kWh. My apologies for not catching that sooner. My thanks to Bill Burke for pointing it out.

 

I’ve tracked battery degradation in the EVs we’ve driven during the past decade. The short answer is that our Nissan Leaf lost a lot, our Chevy Bolts not so much.

I keep detailed logs of our EVs. Beginning with a Nissan Leaf through two Chevy Bolts, I’ve recorded more than a dozen different parameters each time the car is charged. I do this so I can authoritatively answer questions from newbies to EVs and those considering an EV what kind of battery degradation they can expect.

Our 2015 Leaf suffered serious battery degradation in the heat of Bakersfield, California summers where temperatures above 110 F (44 C) are not uncommon. Consequently, the car’s limited range was reduced even further after three years. The Leaf lost 17% of its capacity in only 17,000 miles of travel, leaving us with a piddly 19 kWh when we returned the car to Nissan.

Since switching to the Bolts, we’ve traveled nearly 70,000 miles on three different batteries. Each battery has lost about 5% of its capacity over 20,000 to 30,000 miles. Importantly, this modest capacity loss hasn’t affected how we use the cars or how far we can drive them.

Disclosure: I worked for GM’s Delco-Remy Division 1968-1970 as a cooperative engineering student. I was a member of UAW Local 1981 until the National Writers Union left the UAW in May 2020. The Chevy Bolt is assembled by UAW Local 5960.

Nevertheless, I continue to track the Bolt’s performance. I enter the data on a paper record and then later enter the data into a spreadsheet.

90% of my charging is done at home, and I always charge to 100% when I am not on the road. My reasoning is that most EV drivers will do likewise. Most people will not make any effort to extend the battery’s life. Instead, they will treat the EV much the same as the gasser they replaced it with. They’ll simply “fill it up” and that’s what I am trying to replicate.

Here’s a list of the previous articles I’ve written on this topic.

• Slight Chevy Bolt Traction Battery Degradation after Nearly 30,000 Miles
• Battery Degradation 2020 Bolt Relative to 2017 Bolt EV
• Our Bolt is back with a New Pack—In Limbo No More
• Capacity of 2020 Chevy Bolt with New 2022 Battery after 6500 Miles
• Capacity of 2020 Chevy Bolt with New Battery after 11,500 Miles

After 20,000 miles on the new battery, Torque Pro is showing Bat Cap Est of 56.5 kWh and Bat Cap Raw Ah of 176.6 following the last charge. Since newly installed the battery’s Ah capacity has declined 9%. The calculated capacity has declined about 5%.
In this version of the chart, I’ve dropped the Bat Cap Est as it’s determined directly by the Raw Ah capacity. This has eliminated some of clutter in the chart making the trends easier to see.

What’s noteworthy is that the calculated capacity has only declined 5%. The calculated capacity is what we use to actually drive the car. That’s the number of kWh the car believes it has to work with.

Percent Used Method to Calculate Battery Capacity
We can infer battery capacity by knowing how much of the battery was used for so many kWh consumed between full charges. For example, if on a full charge, we consumed 31.2 kWh and arrived home with 45.9% State-of-Charge. The battery’s calculated capacity is 57.7 kWh.

31.2 kWh/(1-0.459) = 57.7 kWh

This is the battery’s calculated capacity remaining. It’s a good measure of how much battery capacity you have to work with. As noted above, the calculated battery capacity has declined about 5% over 20,000 miles.

After 20,000 miles, the new battery has approximately 60 kWh of usable capacity. The average efficiency of the Bolt during this period is 4.3 kWh/mile. The remaining usable capacity at the average efficiency I’ve measured provides an approximate range of 258 miles after 20,000 miles of use. This is roughly comparable to the EPA estimated range of 259 miles when the battery was new.

2020 Bolt (bought new) with no replacement battery and 44K miles on it. We typically only use it as a commuter car 30 miles a day, occasionally putting a hundred on the weekend - almost always recharge to 100% level one in garage, unless a level 2 freebie charger is available near us while shopping. Anyways we show 5. kWh/Mile Avg Est 330 (High 375, low 300) at full charge as of today. Never measured it when new.

 

Paul did your new battery pack come locked at 80% for the first 6k miles or unlocked and able to charge up to 100%?
At the moment my 2020 is at dealer waiting for new battery pack, I bought as 1 owner new battery w/10k miles. Locked at 80% charge for 6k. But a 17’ish K got a power limit error took to deal they diagnosed need a new battery pack. Thxs for sharing

 

New battery should not have software 80% limit. The software was to detect a potential fault in existing batteries, in part so GM wouldn't have to replace them.

 

Is it safe to say if the Bolt was purchased with the 80% limitation the battery pack was not replaced? Thxs for sharing

 

Most likely. It's possible that the wrong software was applied after a battery replacement (there have been reports of that happening). The best way to determine whether the battery has been replaced is to use the VIN number and follow the instructions from @balazer 's guide:

https://www.chevybolt.org/posts/905302/

 

I don't pretend to understand the ins and outs of the EV batteries, but I do need some help. I had a PHEV and traded it in for a 22 Bolt EUV Premier. $17k out the door, 29,000 miles. I then noticed that the same dealership has a 2020 Nissan Leaf SV plus for $12,500. It doesn't qualify for the tax credit but it's substantially cheaper. It has 41,000 mi on it. I tend to use a car for driving just around town with maybe one or two longer trips a year. I live in Baltimore. I really enjoy driving the bolt. I know some people consider that the leaf is more comfortable, but for me I actually prefer driving the bolt. However, the difference in savings is so big that I'm really second guessing my choice. Based on your research, it sounds as though the bolt may be the better choice in terms of the battery. Is this the case? Or would the Leaf be just fine? Thank you!!

 

I tend to use a car for driving just around town with maybe one or two longer trips a year. I

Based on your research, it sounds as though the bolt may be the better choice in terms of the battery. Is this the case? Or would the Leaf be just fine? Thank you!!

Bolt is definitely the better choice in terms of battery life. If you are looking for a strictly around town second EV, the Leaf could work.

At least in Virginia, CHAdeMO chargers have gone away, or broken without repair, this summer, so road trips seem doubtful.

 

… if they treat is as a gasser, they will only plug in when 30% or lower SOC, so for many that means twice a week to 100%.

 

I don't know which of the three levels is supposed to be 258 with a 100% charge, but I would assume the max. My 2020 with the original battery but only 21,5k miles max miles gauge shows over 300 when charged to 93%. Of course it won't actually go that, but I seriously doubt it would go 258 miles when new.

 

As @bisco pointed out, those GOM predictions have very little to do with the battery's capacity. Read the link below that every member ought to read.

https://www.chevybolt.org/threads/new-owner-psa-—-the-range-display-and-your-bolts-battery.39283/

 

capacity, and estimated miles are not the same thing. estimated miles (guess-o-meter)
is simply a formula used based on past performance recorded in the software.
it can be very accurate, or vary wildly, depending on driving conditions.
capacity is how much energy the battery is capable of storing. that energy can only provide as many miles as conditions allow.