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Discussion Starter · #1 ·
Hello,

What is the official purpose of the small indicator directly left of the SoC indicator. It’s a tiny vertical bar that either extends above or below the GoM range. It seems to correlate to an efficiency indicator for battery draw.
 

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It is a trend vector. If it is going up in green you are increasing range based on current driving conditions. If it is yellow and going down, you are decreasing range based on current driving conditions.

Suppose you drive normally for commuting at low speeds, your GOM will provide a nominal range for that, lets say a range of 260. Now you start out on a trip on a highway at 70 mph, the trend vector will turn yellow and point downward. You will be decreasing the GOM at a rate higher than actual miles travelled. After 20 or 30 minutes the trend vector will zero out and the remaining miles will match closely to actual, assuming no change in terrain, rain, snow, temperature or winds.
 

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...It seems to correlate to an efficiency indicator for battery draw.
Yes, that's precisely what it is. It's a trend indicator to show that your estimated range is trending towards the lower value at the bottom of the GOM or trending towards the higher value at the top of the GOM. That trend is determined by your current (and very recent) efficiency.

For example, let's say you've been driving around in the city, and your GOM currently shows 150 in the middle. Then you get on the highway, so your speed is significantly higher and your efficiency is significantly lower. You'll see the yellow trend line below the center of the GOM, indicating that your estimated range is trending less than 150, towards the low end.

It's one of several signals that the Bolt's Driver Information Center (DIC) sends about your efficiency:
1) miles / kWh number on trip odometer (adjusts most slowly if you have many miles on the trip odometer)
2) GOM (adjust slowly)
3) Trendline to the left of the GOM (adjusts more quickly)
4) Colored circle around the speedometer (adjusts immediately)
5) kW consumption graph to the right of the speedometer (adjusts immediately)

Edit: AZBILL is a ninja!
Edit2: @cwerdna I hang my head in shame. I originally used kWh for the power consumption graph on the right side of the speedometer.
 

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It's actually possible for the vector to go so far positive or negative compared to the GOM estimation that it starts increasing or decreasing the max/min numbers without affecting any other numbers.
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Discussion Starter · #7 ·
This info was very helpful! I like how the info is organized & presented on the dash display. It definitely gives a better understanding that helps promote good battery management. My Kona EV had a much simpler display that only really offered mi/kWh to give a sense of efficiency. There was 1 single GoM # with no upper/lower boundaries. SoC required navigating to the EV screen on the infotainment screen.
 

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The min max is silly.
I think the opposite. If you read the manual, you’d see why they are important.
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The link you posted doesn't explain the reason for why the values are those and not other. There is a lot more in the Min Max values than what you think. Second-guessing the GM engineers looks silly from my chair.

The Min value is IMO very important, especially for those who like to travel with their Bolt EV optimizing their charging times. I drove enough my Bolt EV in long trips to know what I am talking about.

Knowing the Min and Max values are based on current driving conditions & climate settings and that the next leg of the trip is having the same characteristics of the one I just did, all I need is to make sure I have a Min value equal to the distance to the next destination and I am good to go. No need of anything else.

On the same page presented above is the explanation of the trending bar. That’s why reading the manual can help a lot those who are new comers in the world of Bolt EV.
 

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I think the opposite. If you read the manual, you’d see why they are important.
View attachment 43728

The link you posted doesn't explain the reason for why the values are those and not other. There is a lot more in the Min Max values than what you think. Second-guessing the GM engineers looks silly from my chair.

The Min value is IMO very important, especially for those who like to travel with their Bolt EV optimizing their charging times. I drove enough my Bolt EV in long trips to know what I am talking about.

Knowing the Min and Max values are based on current driving conditions & climate settings and that the next leg of the trip is having the same characteristics of the one I just did, all I need is to make sure I have a Min value equal to the distance to the next destination and I am good to go. No need of anything else.

On the same page presented above is the explanation of the trending bar. That’s why reading the manual can help a lot those who are new comers in the world of Bolt EV.
Yup. It's amazing what one can learn by RTFM.
 

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I would split the difference between @Voldar and @cwerdna. The observation that the min is very frequently just a set percentage of the center number does imply a relatively unsophisticated algorithm. However, even if it is unsophisticated, it's still useful when combined with the trend line.

When implementing a trend line, there has to be some target for the trend line. Let's say the center number is 182 and the min number is 163, as shown in that example from the manual. Let's say further that the trend line is halfway between the center of the GOM and the min number. Without the min number, you have no idea what that trend line means, other than a vague "you're getting less efficient by some unknown amount."

With the min number, you know that your efficiency is trending towards a range of ~172 miles.
 

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I would split the difference between @Voldar and @cwerdna. The observation that the min is very frequently just a set percentage of the center number does imply a relatively unsophisticated algorithm. However, even if it is unsophisticated, it's still useful when combined with the trend line.

When implementing a trend line, there has to be some target for the trend line. Let's say the center number is 182 and the min number is 163, as shown in that example from the manual. Let's say further that the trend line is halfway between the center of the GOM and the min number. Without the min number, you have no idea what that trend line means, other than a vague "you're getting less efficient by some unknown amount."

With the min number, you know that your efficiency is trending towards a range of ~172 miles.
The same goes for the Max value.
If you have a trending line towards the Max value and you have to choose between a DCFC 20 miles away and another one at 40 miles, you might want to go to the one at 40 miles away. This can happen for exemple when you come after a long climbing and now you are on the "going-down" side of the hill. The Min value doesn't help you much in this case, but the trending bar and the Max value, does.

Yes, you'd arrive there with a lower state of charge of your battery, but based on how the Bolt EV charging curve is, this implies that you'll have a better charging speed overall.

In a word : you benefit from having Max and Min values. And GM did a great job, starting since the begining when the Spark EV was put on the market.

Without them, you just do what everyone does : overcharge = overpay for the DCFC.
Instead of charging to what you need, you charge to 80% SOC just because everyone says to do it. And then you come and complain here how slow the Bolt EV charges, when you only needed a 55% SOC to get to the next destination. So you spent 20 minutes too much on the DCFC and somehow it's the fault of GM.
 

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I think the opposite. If you read the manual, you’d see why they are important.
View attachment 43728

The link you posted doesn't explain the reason for why the values are those and not other. There is a lot more in the Min Max values than what you think. Second-guessing the GM engineers looks silly from my chair.

The Min value is IMO very important, especially for those who like to travel with their Bolt EV optimizing their charging times. I drove enough my Bolt EV in long trips to know what I am talking about.
The min may not even be correct because it cannot predict the future. The 0.82 may not be correct at all if suddenly, the driver goes from slow level ground or downhill city driving to 70+ mph steep uphill driving.

Those values were frankly silly. I've read the manual many times, including that section. Whenever I've checked, I've never found a case where the max wasn't the middle value * 1.18. And, it's 0.82 * middle value most of the time, until it isn't.

But the values are GOMs, which are not particularly great. 2013 SL - Range Dropped quickly - My Nissan Leaf Forum applies just as much to Bolt as it does to Leaf. I had a Leaf from end of July 2013 to mid-2021.
 

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IMO, what other automakers did with their GOM is just that. A guess-o-metter that people don't use really, they usually follow the efficiency numbers : mi/kWh.
GM did something different, they put in place a tool that once understood, is simple to follow.
 

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The min may not even be correct because it cannot predict the future. The 0.82 may not be correct at all if suddenly, the driver goes from slow level ground or downhill city driving to 70+ mph steep uphill driving.

Those values were frankly silly. I've read the manual many times, including that section. Whenever I've checked, I've never found a case where the max wasn't the middle value * 1.18. And, it's 0.82 * middle value most of the time, until it isn't.
When you'll understand that the Min and Max are not numbers that remain the same, they move up and down based on the current driving conditions and the climate settings... There is nothing about the "future".
I am not sure why are you still complaining about the Min and Max values. You have no longer a Bolt EV, you never used them anyway.

Edit : The "future" is represented by the trend line.
 

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When you'll understand that the Min and Max are not numbers that remain the same, they move up and down based on the driving conditions and the climate settings...
I am not sure why are you still complaining about the Min and Max values. You have no longer a Bolt EV, you never used them anyway.
Not complaining. Just pointing it out.

Given that I find the GOM nearly worthless and not worth paying much attention to (let alone worrying about), why would I care much about the GOM * 1.18 and GOM * (usually) 0.82?

The GOM and thus the 3 numbers all move up and down based upon a black box (only described at high levels in the manual and TSBs) and climate settings.
 
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