Chevy Bolt - 200 mile range for $30k base price (after incentive)

[bro1999]

2017 Chevy Bolt EV battery may fail due to faulty cell; new pack needed for a few GM electric cars

Hadn't heard from Bro in a while, any chance he's stuck on the side of the road somewhere?

Nope, my Bolt and I are just fine. Just recently took another ~300 mile road trip to Shenandoah NP to see the solar eclipse, actually. Approaching 10k problem-free miles.
Bummer a few owners have this battery issue. I imagine this issue could have been much bigger if GM had not done their extensive pre-production testing!

 

[JohnSnowNW]

Nope, my Bolt and I are just fine. Just recently took another ~300 mile road trip to Shenandoah NP to see the solar eclipse, actually. Approaching 10k problem-free miles.
Bummer a few owners have this battery issue. I imagine this issue could have been much bigger if GM had not done their extensive pre-production testing!

Glad to hear, though the original article made it seem that GM is unsure of how many vehicles are affected, and the <1% remark seems more PR oriented. Keep an eye out.

 

[McRat]

2017 Chevy Bolt EV battery may fail due to faulty cell; new pack needed for a few GM electric cars

Hadn't heard from Bro in a while, any chance he's stuck on the side of the road somewhere?

Here's how it is on a Volt array:

There are multiple BMS boards on the battery assy that are not field serviceable. They use plastic welding to insure mechanics do not disassemble the assy. I've taken them completely apart (don't do this at home).
Their default fail mode is to send a signal over the bus that there is a failure in a module.
This is for safety purposes. If a failed BMS board did not default to HVDC failure, there is a serious fire risk.
So the entire battery assy is replaced as a unit for field servicing.
The cells are then used to power the UPS and energy storage at a GM HQ.

I would be surprised if the Bolt architecture was significantly different.
To date, so far GM has reported publicly that no lithium batteries have failed in retail cars, which is probably still true.

All EV makers so far still deal with such issues, much like ICE vehicles have engines and transmissions replaced, except the engines and transmissions do not have an 8 year warranty in general.

Getting a car towed for service, then replacing an entire major assy is not an EV issue. It is an automobile issue from which no automaker has proven to be immune.

 

[Jeff N]

Nope, my Bolt and I are just fine. Just recently took another ~300 mile road trip to Shenandoah NP to see the solar eclipse, actually. Approaching 10k problem-free miles.

Similar story for me. I just got back from an excellent 1,100 mile trip to central Oregon in my Bolt to see the eclipse. I now have 14,600 miles on my car.

I've now done SF to LA 3 times, a one-day round trip to Fresno, a ~2,300 mile trip to visit national parks in Utah, and this recent trip to Oregon.

I should probably take it in for a tire rotation and some software updates (since they still haven't begun utilizing the built-in OTA update mechanism yet). I have a very early build car (first couple weeks of customer production).

 

[Jeff N]

Here's how it is on a Volt array:

There are multiple BMS boards on the battery assy that are not field serviceable. They use plastic welding to insure mechanics do not disassemble the assy. I've taken them completely apart (don't do this at home).
Their default fail mode is to send a signal over the bus that there is a failure in a module.
This is for safety purposes. If a failed BMS board did not default to HVDC failure, there is a serious fire risk.
So the entire battery assy is replaced as a unit for field servicing.
The cells are then used to power the UPS and energy storage at a GM HQ.

I would not be surprised if the Bolt architecture was significantly different.

I think you are describing the pack of the 1st generation Volt PHEV. I've been told the Bolt EV pack basically shares the same cell monitoring/balancing circuit board design as the 2nd generation Volt. I'm not sure about the 2nd generation Volt pack's circuit board(s) physical location.

Here's a cut-away model photo of the Bolt's board:

On the first generation Volt, some of the circuit boards can be individually replaced without swapping the whole pack or even an entire module. I know this because one of my monitoring/balancing boards was automatically self-diagnosed as failing and had to be replaced after the car's 4th year with just over 100,000 miles. As far as I know, this is a rare failure mode on the 1st gen Volt and not a common problem.

The new board was ~$250 but it required the dealer mechanic to drop the whole pack from the car and open the cover to replace it so most of the cost was labor.

Here is the part, shown in green, in a diagram showing how it attaches to a frame running along the top of its battery module. There are four modules and thus four cell monitoring/balancing circuit boards in the overall Volt pack:

Control Module - GM (22885655) | GMPartOnline

 

[KarenRei]

I'm not surprised that most people are reporting that their Bolt is running well. While I'm frequently disappointed by GM management's understanding of the market, and rarely like their attitude toward styling (materials that don't match up with the vehicle's price point, bad body styling aesthetics given priority over aerodynamics, etc), they've always had good people on the engineering side of their EV programmes over the years. I've worked with some of them before.

The best decision GM could make is to spin off their electric division into a well-capitalized, entirely electric company (not just a brand), and leave it to manage itself rather than stacking it with a GM-subservient board. GM is an anchor on its electric vehicles' future, not the other way around.

 

[McRat]

I think you are describing the pack of the 1st generation Volt PHEV. I've been told the Bolt EV pack basically shares the same cell monitoring/balancing circuit board design as the 2nd generation Volt. I'm not sure about the 2nd generation Volt pack's circuit board(s) physical location.

Here's a cut-away model photo of the Bolt's board:

View attachment 243664

On the first generation Volt, some of the circuit boards can be individually replaced without swapping the whole pack or even an entire module. I know this because one of my monitoring/balancing boards was automatically self-diagnosed as failing and had to be replaced after the car's 4th year with just over 100,000 miles. As far as I know, this is a rare failure mode on the 1st gen Volt and not a common problem.

The new board was ~$250 but it required the dealer mechanic to drop the whole pack from the car and open the cover to replace it so most of the cost was labor.

Here is the part, shown in green, in a diagram showing how it attaches to a frame running along the top of its battery module. There are four modules and thus four cell monitoring/balancing circuit boards in the overall Volt pack:

Control Module - GM (22885655) | GMPartOnline

I stand corrected, perhaps due to senility or stale data. I did have to cut off plastic welding tabs to disassemble my junkyard 2012 Volt battery. My race mechanic worked at a GM dealer since before the Volt came out until about 2015 and had went to the hybrid powertrain training. He told me when there were was a battery related error, they were instructed not to disassemble the battery, just to ship it whole back to GM. This had come up because he told me I should not take it apart.

I can't find the video when cut the pack down to individual cells. But that is probably best not shown to people. The cells are spot welded together without much room, so it is really dangerous to cut the cells out.

 

[Jeff N]

I can't find the video when cut the pack down to individual cells. But that is probably best not shown to people. The cells are spot welded together without much room, so it is really dangerous to cut the cells out.

When the Volt first came out GM told dealers to swap entire packs in order to simplify the process of engineering folks evaluating the root cause of failures. Later on, dealers started swapping modules and even doing limited repairs like replacing module control boards.

The cells are not spot welded to each other but the positive and negative power tabs along the top of the cell are spot welded to the pack wiring bus in some fashion. The pouch cells are placed into plastic frames along with active aluminum cooling fins and the frames are then pressed together under tension into a module section. I said earlier there are 4 modules in a Volt pack. That's not right. There are 4 unique module types: 22 cell vs 30 cell vs ..... so there are 4 different matching monitoring/balancing board types. Wikipedia tells me there are actually 11 modules using those 4 module types that make up the overall 1st generation pack.

 

[McRat]

When the Volt first came out GM told dealers to swap entire packs in order to simplify the process of engineering folks evaluating the root cause of failures. Later on, dealers started swapping modules and even doing limited repairs like replacing module control boards.

The cells are not spot welded to each other but the positive and negative power tabs along the top of the cell are spot welded to the pack wiring bus in some fashion. The pouch cells are placed into plastic frames along with active aluminum cooling fins and the frames are then pressed together under tension into a module section. I said earlier there are 4 modules in a Volt pack. That's not right. There are 4 unique module types: 22 cell vs 30 cell vs ..... so there are 4 different matching monitoring/balancing board types. Wikipedia tells me there are actually 11 modules using those 4 module types that make up the overall 1st generation pack.

Not only are the 3 cells "instant" high-pressure-pressed cleated spotwelded, the transfer plates are thick. So you must cut through 3 battery tabs and the copper, without touching anything metal to the tab that is 12mm away on average (under 1/2"). Even floating cutting dust or a thin metal shaving will explode like a firecracker and could damage your eyesight permanently. Those two contacts are 100% dead short amps available. Voltage hurts, amps kill.
That's why you see the rubber tubes protecting the tabs.
Don't mess with batteries at this level.
You can see that in this pic I was just starting to remove cells from the right hand end of a 2kWh+1kWh module.

 

[McRat]

Interesting. The MSRP at full dealer retail for a Bolt EV battery is $16,250 GM PN 24286782. It appears a core is not necessary. But they have been wrong before.

BUT! There are two versions. One is apparently obsolete already.

$13,000 shipped to CA.

 

[AndY1]

2017 Chevy Bolt EV battery may fail due to faulty cell; new pack needed for a few GM electric cars

Hadn't heard from Bro in a while, any chance he's stuck on the side of the road somewhere?

Well, well, some of you have already forgotten about many many Model S drivetrain failures.

Do I need to dig out that thread with the poll?

 

[RubberToe]

I'm not surprised that most people are reporting that their Bolt is running well..

And away we go!

GM warns some Bolt EV owners that they are recalling a few battery packs that can shut down

 

[ZsoZso]

Well, well, some of you have already forgotten about many many Model S drivetrain failures.

Do I need to dig out that thread with the poll?

Please do, if you know about any Model S that left the owner on the road-side due to drive-train failure!
I think you are mixing up a purely cosmetic issue (noise in case of Model S) and a fatal failure (stranded roadside by Bolt).
My drivetrain was replaced due to the noise under warranty free of charge while I was driving a loaner Model S for the day, no drama or inconvenience.

 

[McRat]

And away we go!

GM warns some Bolt EV owners that they are recalling a few battery packs that can shut down

Read the last dozen so posts. Skip the tech ones. This was already posted.

 

[McRat]

Please do, if you know about any Model S that left the owner on the road-side due to drive-train failure!
I think you are mixing up a purely cosmetic issue (noise in case of Model S) and a fatal failure (stranded roadside by Bolt).
My drivetrain was replaced due to the noise under warranty free of charge while I was driving a loaner Model S for the day, no drama or inconvenience.

Yes, Teslas have been towed to dealer due to drivetrain failures. God did not make Teslas. People did. There is a failure rate. It's true for all cars.

 

[techmaven]

Look... every manufacturer has issues and especially those that are pushing new technology. Every single Model S battery pack built from 2012 through some time in 2014 had to have its contactor replaced. That's a stranding failure. Now, most of them were replaced at annual service. Some immobilized the car. The reality is that if you go back through the recall records across the industry, there have been tons of them in the past few years, some for small things and some for big things. Every single Ford Ecoboost engine had to be recalled for possible fire problems... more than once! The Ford Escape went through 7 recalls in its initial redesign:
Recall No.7 for Ford Escape; This time there's a fire danger - NBC News

It doesn't help when @bro1999 goes around throwing shade at Tesla here and all over the place, and it doesn't help when Tesla fans throw shade at GM over things like this. GM is sh*t for what they are doing with the ignition lock failures (which is ongoing) and letting people go to jail when they knew of alternate explanations for what happened to them. But this Bolt pack issue doesn't appear to be beyond normal issues of engineering and mass production of a new vehicle. And it also doesn't help that then people completely screw up what was wrong with Tesla vehicles... and it goes to show just how new all of this is... people can't distinguish, yet, the difference between swapping out a drive unit or battery pack for a small fix versus a complete loss of part. Plenty of people still think that Tesla's widespread drive unit issues were stranding issues and/or required throwing away the old unit. Nothing of the sort. For example, the battery pack contactor failure is like a $50 part, probably $500 in repair costs, most of which are labor and shipping. Not $25,000 that some people implied in various forums. In the end, that exaggerated narrative hurts all EVs.

It is also telling that this forum and others go into meltdown mode whenever something happens to Tesla vehicles, but the various Bolt forums are pretty quiet about this recall. Pretty much everything Tesla is hyped especially since Tesla carried the EV torch and there are a wide array of enemies.

We will need more information before we know if this pack/BMS issue is really a minor one, which is likely, or something more. It is cool that they can use OnStar to try to figure out which vehicles are most effected. That's progress.

 

[EinSV]

I am no fan of how GM is handling EVs in general and the Bolt in particular, but some teething pains are typical in a new car design. If this problem is as limited as GM says, it doesn't seem any different than issues that typically crop up in the first year of a new model. Seems like it's not a big deal.

 

[JohnSnowNW]

Well, well, some of you have already forgotten about many many Model S drivetrain failures.

Do I need to dig out that thread with the poll?

Nah, your incessant posts in the issues threads are burned into everyone's minds.

 

[Jeff N]

CR follows up on Bolt vs S75 range test controversy:

How Consumer Reports Tests Electric-Vehicle Range

 

[jsmay311]

CR follows up on Bolt vs S75 range test controversy:

How Consumer Reports Tests Electric-Vehicle Range

Probably the most relevant piece of information that CR released regarding its test procedure:

"We put our EVs into their less-aggressive regenerative braking mode; regenerative brakes help EVs recapture some of the energy lost in braking. Many EVs have a mode with aggressive regenerative braking that’s meant to capture more of that energy, but it can be an intrusive experience, making the brakes seem grabby, especially for drivers who are new to EVs."
​

Since the Bolt (like most non-Tesla EVs) adds additional regen when depressing the brake pedal before engaging the brake pads, having it in its "less-agressive regenerative braking mode" (i.e., "D" instead of "L") would have a minimal negative effect on its total amount of regen, overall efficiency, and total range.

But since Teslas don't increase regen when depressing the brake pedal, setting the regen setting to "low" instead of "standard" would have a significant negative effect on overall efficiency and range. And this penalty would only be amplified by the fact that the Model S is significantly heavier than the Bolt.

So I'd say that, in a way, this is good news for Tesla since it clearly shows that the earlier CR test results showing the Bolt outperforming the S75D were not a fair comparison. Too bad CR didn't provide even more details about their testing drive cycle so we could even better understand the results.