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Little bit difficult to understand.
Above recent posts are attempting to indicate:

1. In one person’s observations, Bolt makes some regenerative braking force available quite soon after setting off after battery has been charged to “full”. That is, when the regen spinner icon towards the bottom right of the 8-inch screen remains grayed out. (that spinner turns to green in color when the system decides that normal regenerative braking is available).

2. According to Motor Trend, Bolt delivers greater regenerative braking force (L mode + paddle engaged) as compared to LeafII and Model 3.
 

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According to Motor Trend, Bolt delivers greater regenerative braking force (L mode + paddle engaged) as compared to LeafII and Model 3.
Never driven a Model 3 but I've driven a Model S plenty of times and even with the regen settings turned up to the max the car does not regen anywhere close to as much as the Bolt does in L mode even without using the paddle.
 

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This is the $64 question. I show some regen on Torque Pro even when the icon is grey.
When the icon is grey, there is a white line on the regen display which shows the regen limit. You have exactly that much regen available, no more. The line moves: charge the battery more with regen and it'll go down to less regen available, drive some and it'll move down.
 

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When the icon is grey, there is a white line on the regen display which shows the regen limit. You have exactly that much regen available, no more. The line moves: charge the battery more with regen and it'll go down to less regen available, drive some and it'll move down.
I know, but one of the arguments was that there was NO regen available when the battery's full.
 

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what bothers me about the efficiency bar graph is that when I go down a long hill, the regen causes my miles/kWh to be 252...when it displays 252, then all the bars that are 5kWh become very tiny and meaningless. they average in this 252 with the other 9 bars of 5, and they say I'm getting 30m/kWh. meaningless. they need to fix how they handle regen on the bar graph.
 

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Discussion Starter #127
Yes, this is why I arranged a call to the chief engineer (and have written a paper on the subject). Their answer, as stated earlier in this thread, is that they did not want to confuse the driver by putting the red average line at the correct place -- because the driver expects the average to be at the average of the green bars. That is why they placed the red line at the avg. of the bar heights, even tho well aware that this often leads to 1000% or even 2000% error in the red line. Ridiculous. My paper on the subject gives several things they could have done to make it right.

The fact that 252 is used as a proxy for either a much larger number, or for any negative number is not a big problem. The location of the red line is a big problem. My paper is at

http://stanwagon.com/public/MHArticleProofs.pdf
 

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Nice explanation Stan. I've mentioned the Mile Per Gallon illusion to people on a couple occasions since reading about it in Daniel Kahneman's book "Think Fast, Thinking Slow" a few years ago, but quickly learned I just get puzzled looks. It is similar to the problem with percentages described in Darel Huff's little book "How to Lie with Statistics" written decades ago.

I hope the GM engineers listened and change their display, but I doubt you will get them to adopt the RHS scale with infinity on it.
 

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Discussion Starter #129
Thanks for comment. If you want a copy of my published paper on this, it is at stanwagon.com/public/MHArticleProofs.pdf

I have every reason to believe that the bar chart on the 2019 Bolt (mine is 2018) might have some cosmetic changes, but is unchanged as regards the average being at the VERY wrong value. So I do very often switch to metric as I drive so I can see how the average is really doing, having learned that 15.5 is the metric equivalent of 4 mi/kWh.

And to repeat, because I live in the mts. with big downhills, the bar chart as it is is generally quite useless with the giant 252 value dwarfing everything else. But I still love the Bolt of course. Even in cold weather I can get from here to Denver and back with no problem. Last trip, though, I charged at a SEMA station while having dinner. It was difficult to make phone contact with SEMA to get it going, but after 4 tries I got through. Just for safety, as the extra elec. was not really needed to get home.
 

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There absolutely is regen available at all times, unless you just unplugged and are going downhill for a bit.

The system has a maximum voltage of 400V, which generally it's pretty good at sticking to (I've seen as high as 404 peaked under regen).

The battery, unplugged, is never at 400V (unless you've already filled it up with some regen), So if your battery is at 399V, then you'll get 1V of regen, which is going to be a few kW at least.
 

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A recent incident with a friend who owns a 2019 Bolt EV makes me think that GM made some more significant adjustments than I've seen talked about.

My friend had been charging to 100%, but she didn't really need the full range on a day-to-day basis. So I showed her how to set the Charge Limit feature, and we set her battery to charge to only 95% (she had already charged past that point when we reset the limit). A short time later, she flagged me down, asking me why her regenerative braking went away.

Now, that is strange for two reasons. First, regenerative braking should only look at the total available capacity of the battery, regardless of settings. In other words, limiting the level you charger your battery to should have no bearing on regenerative braking availability. Second, she had not experienced that behavior before, despite recharging to 100% on numerous occasions. That means that GM must have found some other way of enabling regenerative braking on a "full" battery (I'm not sure whether it's additional, unusable capacity, or some sort of power feedback to the motor).

Of course, I've also seen some Bolt EV owners claiming to charge at 60 kW on some of the higher power chargers, though I haven't been able to verify. If that is true, that means that GM either upped the charging rate to the full 1 C rating of the battery cells or GM maintained the same C rate charging but increased the battery size.
 

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...we set her battery to charge to only 95% (she had already charged past that point when we reset the limit). A short time later, she flagged me down, asking me why her regenerative braking went away.
Are we sure that there wasn't some coincidental reason, such as she happened to take the car down a hill that she doesn't often use? Regen does still work at 100% charge, it's just not capable of dealing with very high deceleration loads like going down slopes or slowing from high speeds.
 

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Are we sure that there wasn't some coincidental reason, such as she happened to take the car down a hill that she doesn't often use? Regen does still work at 100% charge, it's just not capable of dealing with very high deceleration loads like going down slopes or slowing from high speeds.
This was her normal drive, so that adjustment (to 95%) was the only change.
 

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A recent incident with a friend who owns a 2019 Bolt EV makes me think that GM made some more significant adjustments than I've seen talked about.

My friend had been charging to 100%, but she didn't really need the full range on a day-to-day basis. So I showed her how to set the Charge Limit feature, and we set her battery to charge to only 95% (she had already charged past that point when we reset the limit). A short time later, she flagged me down, asking me why her regenerative braking went away.

Now, that is strange [...]
The simplest explanation is not that somehow GM has found a way to allow regen at 100%, but that your friend is mistaken somehow.

Perhaps she was never charging to 100% to begin with.

Operator error.
 

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The simplest explanation is not that somehow GM has found a way to allow regen at 100%, but that your friend is mistaken somehow.

Perhaps she was never charging to 100% to begin with.

Operator error.
Based on what I've seen, it's not operator error, which is why my current theory is that GM capped the usable capacity at a point that allows significant (maybe not full) regen when the battery is displaying 100%.

That would mean, though, that GM needs to do a software update that re-enables full regen even when the battery is maxed out at whatever the Charge Limit is set to. In other words, if you are at 90% battery when the Charge Limit is set to 85% or 90%, full regeneration should be available.
 

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A recent incident with a friend who owns a 2019 Bolt EV makes me think that GM made some more significant adjustments than I've seen talked about.

My friend had been charging to 100%, but she didn't really need the full range on a day-to-day basis. So I showed her how to set the Charge Limit feature, and we set her battery to charge to only 95% (she had already charged past that point when we reset the limit). A short time later, she flagged me down, asking me why her regenerative braking went away.

Now, that is strange for two reasons. First, regenerative braking should only look at the total available capacity of the battery, regardless of settings. In other words, limiting the level you charger your battery to should have no bearing on regenerative braking availability. Second, she had not experienced that behavior before, despite recharging to 100% on numerous occasions. That means that GM must have found some other way of enabling regenerative braking on a "full" battery (I'm not sure whether it's additional, unusable capacity, or some sort of power feedback to the motor).

Of course, I've also seen some Bolt EV owners claiming to charge at 60 kW on some of the higher power chargers, though I haven't been able to verify. If that is true, that means that GM either upped the charging rate to the full 1 C rating of the battery cells or GM maintained the same C rate charging but increased the battery size.
Like your friend, I have a 2019. I have experienced the same regen braking with a 100% charge. However, before I can try to regen brake, I must use energy to "get up to speed." I do not live at the top of a hill so there will always be more capacity available from "getting up to speed" than the regen braking can generate. I attached a photo of the display which shows the 100% charge and the regen icon grayed out. The second photo is a close up of the icon. But regen braking still works.

I did a test today with the charge limit set at 50% and the current charge at about 70%. (See 3rd photo.) Regen braking worked normally.

I normally charge to 90% so I have only tested it at a 100% charge a couple of times. I will do a 100% charge tonight and then set to 95% charge limit to see if I can reproduce her results.

I have never done a DC fast charge, so I don't know what the max charge rate is. However I do recall seeing 70kW when doing hard regen braking tests. It repeated this several times - always a max of 70kW. So it looks like for a short burst, the battery will take even more than 60kW. Sorry no photo.
 

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Like your friend, I have a 2019. I have experienced the same regen braking with a 100% charge. However, before I can try to regen brake, I must use energy to "get up to speed." I do not live at the top of a hill so there will always be more capacity available from "getting up to speed" than the regen braking can generate. I attached a photo of the display which shows the 100% charge and the regen icon grayed out. The second photo is a close up of the icon. But regen braking still works.

I did a test today with the charge limit set at 50% and the current charge at about 70%. (See 3rd photo.) Regen braking worked normally.

I normally charge to 90% so I have only tested it at a 100% charge a couple of times. I will do a 100% charge tonight and then set to 95% charge limit to see if I can reproduce her results.

I have never done a DC fast charge, so I don't know what the max charge rate is. However I do recall seeing 70kW when doing hard regen braking tests. It repeated this several times - always a max of 70kW. So it looks like for a short burst, the battery will take even more than 60kW. Sorry no photo.
Thanks!

Yes, your experiences mirror what I would expect to see happen. Some (but not full) regen at 100%.

What I find worrisome is that it appeared as though she had zero regen available. Now, she might have been close to full (it hadn't reset the Energy Information screen), but it was at all 20 green bars on the Range Estimator. It's possible that there's some weird quirk where even the limited regen available at 100% is more than the regen available at ~99% with 95% selected on the Charge Limit.
 

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Thanks!

Yes, your experiences mirror what I would expect to see happen. Some (but not full) regen at 100%.

What I find worrisome is that it appeared as though she had zero regen available. Now, she might have been close to full (it hadn't reset the Energy Information screen), but it was at all 20 green bars on the Range Estimator. It's possible that there's some weird quirk where even the limited regen available at 100% is more than the regen available at ~99% with 95% selected on the Charge Limit.
I will see what happens tomorrow when I try to mirror her test conditions.
 

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Like your friend, I have a 2019. I have experienced the same regen braking with a 100% charge. However, before I can try to regen brake, I must use energy to "get up to speed." I do not live at the top of a hill so there will always be more capacity available from "getting up to speed" than the regen braking can generate. I attached a photo of the display which shows the 100% charge and the regen icon grayed out. The second photo is a close up of the icon. But regen braking still works.

I did a test today with the charge limit set at 50% and the current charge at about 70%. (See 3rd photo.) Regen braking worked normally.

I normally charge to 90% so I have only tested it at a 100% charge a couple of times. I will do a 100% charge tonight and then set to 95% charge limit to see if I can reproduce her results.

I have never done a DC fast charge, so I don't know what the max charge rate is. However I do recall seeing 70kW when doing hard regen braking tests. It repeated this several times - always a max of 70kW. So it looks like for a short burst, the battery will take even more than 60kW. Sorry no photo.
I think there is a fundamental misunderstanding here. Regen is not “greyed out”, it is merely limited. That's the status at 100% charge. That's how it has always been in the Bolt, despite some people claiming that “at 100% there is no regen”. There is regen, just not as much.

There is a white line in your first screenshot which shows the current regen limit.

If you can show regen beyond the white limit line, then I might believe these tails about something new happening.
 

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I think there is a fundamental misunderstanding here. Regen is not “greyed out”, it is merely limited. That's the status at 100% charge. That's how it has always been in the Bolt, despite some people claiming that “at 100% there is no regen”. There is regen, just not as much.

There is a white line in your first screenshot which shows the current regen limit.

If you can show regen beyond the white limit line, then I might believe these tails about something new happening.
I have a 19 and was going to point out the white line, but you beat me to it. You get some regen, but not beyond that line. Caught me off guard since I normally charge only to 85% (winter.... Ug... I need warmer morning temps), but going to a ski resort I charged to 100%. Going down my normal hill I was in L and let off like normal. I was "sorta" slowing. Took a second to realize that I was regen limited. It would slow you but not by much and you will need to use brakes.

Also have seen it when the battery is cold. Same look, white line and the regen battery is grayed out.
 
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