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Hi All,

I just picked up my new 2017 Volt last week for a good price and have noticed that the chargers i use at work (Level 2 Chagerpoints) have been adding 1 mile per charge to the top. So instead of the charging stopping at 53 miles I hit +1 every time (59 today), and expect to hit 60 tomorrow if the trend continues.

I looked online and did not see any other discussions about this...has anyone heard of this? A couple miles might be understandable with the heating of the battery during charging but it has been consistent every charge with adding 1 mile to the total range and I stop it as soon as the Volt sends me the text saying charge is complete.
 

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Hi All,

I just picked up my new 2017 Volt last week for a good price and have noticed that the chargers i use at work (Level 2 Chagerpoints) have been adding 1 mile per charge to the top. So instead of the charging stopping at 53 miles I hit +1 every time (59 today), and expect to hit 60 tomorrow if the trend continues.

I looked online and did not see any other discussions about this...has anyone heard of this? A couple miles might be understandable with the heating of the battery during charging but it has been consistent every charge with adding 1 mile to the total range and I stop it as soon as the Volt sends me the text saying charge is complete.
It can't really overcharge.
What you are witnessing is the self-adjustment of your anticipated range based on growing statistical data from your most recent drives.
Sounds like you're doing great!

Welcome to gm-volt.com
WopOnTour
 

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Funny. I haven't heard of this either, in this way. Congrats seem to be in order. What you're looking at is an estimate based on conditions and prior driving history. My guess is you go downhill to work so, as you charge, the estimate assumes you're going further per kWh. While this exact situation hasn't occurred before, changing range estimates happen all the time. For an eye popping range estimate, start in the the mountains and drop 6000 feet or so and see what happens!

Bottom line is that most likely it's just a change in the estimate. Likely no reason to worry and likely nothing to do with the EVSE you're using.
 

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I was not aware it did this, pretty cool. What is even more interesting...is that i live in Tampa, most of my drive to work is freeway with a little stop-go at the ends.
 

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In other words, you're driving the car like a grandpa. Try driving it like Jeff Gordon for awhile, and you'll see the guessometer plummet in EV range. There's nothing wrong with your EVSE. The car won't overcharge your battery so don't worry that you somehow have a defective volt.
 

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Very cool, I did not know the car did forecasting like that. Being in Florida i expected my numbers to be lower because of less regen opportunity. I will keep riding it and see how high I can get it to read at top off.
 

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Very cool, I did not know the car did forecasting like that. Being in Florida i expected my numbers to be lower because of less regen opportunity. I will keep riding it and see how high I can get it to read at top off.
Definitely not a big altitude drop in Tampa. That's for sure. Regen gets some of the energy back but it's better not to use in in the first place. Warm weather helps as does low speeds. You might be seeing the effects of slow stop-go traffic. A silver lining of heavy traffic when you're in a EV is longer range.
 

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You're looking at a range estimate, not the amount of energy in the battery. Notice the gas range estimate also changes even when you haven't used any gas.
 

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In summary that number you see in the lower left hand corner of the DIC is a prediction of how far you "might" go if you drive EXACTLY like you have for the last few drives. That number will go UP and DOWN so don't freak out when it drops like a stone if you ever get to drive your Volt in cold weather.

Folks up north are seeing reductions as much as 20 miles from their summer time high's. All is well.
 

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It can't really overcharge.
What you are witnessing is the self-adjustment of your anticipated range based on growing statistical data from your most recent drives.
Sounds like you're doing great!

Welcome to gm-volt.com
WopOnTour
I concur. Congrats and enjoy the ride :)
 

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Humans see patterns in observations. That's the design of a human. A lot of times those perceptions are statistically incorrect.

Graph a year of guess-o-meter data before jumping to the conclusion of "Adding miles every time I charge at work. Must be over charging.".

There are many examples of this human thing. The over-unity aka perpetual-motion folks, for example, are entertaining.
 

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Very cool, I did not know the car did forecasting like that. Being in Florida i expected my numbers to be lower because of less regen opportunity. I will keep riding it and see how high I can get it to read at top off.
Actually, avoiding regen is better than doing lots of regen (unless you can find a way to go to work and do the return commute downhill both ways). Regen is only recaptures something like 70% of your momentum converting it back into energy, so you are definitely better off keeping your momentum as movement.
 

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Regen gets some of the energy back but it's better not to use in in the first place.
I'm sorry, this is the first I've read of this. I am not a volt owner, forgive me, but interested in purchasing one. So, to be clear: we should not use brake regen?
 

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DonC said:
Regen gets some of the energy back but it's better not to use in in the first place.
I'm sorry, this is the first I've read of this. I am not a volt owner, forgive me, but interested in purchasing one. So, to be clear: we should not use brake regen?
As a thought experiment, suppose you have a completely drained battery and accelerate (on flat ground) from 0 to 40 MPH using the gas engine, then immediately use regenerative braking to slow to a stop. The energy you recover goes into the battery, which now has charge you can use to accelerate the car -- but if you do so, using nothing but the battery, you won't get up to 40 MPH. I don't know offhand how fast you could end up going -- 10 MPH, 20 MPH, maybe 30 MPH, but not 40 MPH (on level ground). This is all a factor of the inefficiency of technology; it's impossible for modern regenerative brakes to recapture 100% of the energy used to bring the car up to speed. Some of the energy gets dispersed as heat or in other ways. The same is true over other speed ranges, too -- if you accelerate from 40 MPH to 60 MPH and then brake back to 40 MPH, you won't get back enough energy to go back up to 60 MPH.

(Of course, the above thought experiment simplifies a lot of details, like the fact that the Volt's batteries should never be completely drained, and the fact that regenerative braking in a Volt won't bring it quite to a full stop. It's just an idealized thought experiment meant to illustrate a point.)

So, from a practical driving point of view, the order of preference for saving energy is:

  1. Accelerate only as much as you must. For instance, in city traffic, pay attention to the traffic a block or two ahead, to stop lights ahead, and so on, so that you can minimize your use of brakes. On the highway, let off the accelerator and coast prior to braking at an exit. (Of course, it's possible to take such techniques to an extreme that will annoy other drivers, and I'm not advocating that.) Higher speeds, especially beyond a certain point, are less energy-efficient than slower speeds, so don't drive too fast, either.
  2. Use regenerative braking. On a Volt, you can do this via the "L" setting on the shifter, via the regen paddle on the steering wheel, or via light to moderate use of the brake pedal. Using regenerative braking recaptures some of the energy carried in your momentum.
  3. Use conventional brakes. When applied hard, and when you get below some slow speed (5 or 10 MPH, IIRC), the brake pedal uses conventional brakes. This braking method converts your momentum into waste heat. Of course, you shouldn't hesitate to brake hard when it's required for safety!
FWIW, I'd been taught to do #1 in my driver's education class in high school; and although regenerative brakes were not yet available then, light braking was also recommended as being better for wear and tear on the brake systems. Thus, I've been well-trained to drive a modern hybrid or electric car. I'm sure the same is true of many others -- but we've all witnessed people who accelerate fast and leave braking to the last moment, which wastes fuel even in conventional cars.
 

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From several places that the Volt engineering is documented, we know that the regen cycle is 70% efficient. That's really efficient for such things, but yeah, it doesn't beat not putting it back into the battery in the first place.
 

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I live in the Shenandoah Mountains.... you should SEE how much my numbers vary depending on where I have to travel during the week.

Chevy Volt... driving this OCD guy to distraction since Dec 2015 <grin>.
 

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From several places that the Volt engineering is documented, we know that the regen cycle is 70% efficient. That's really efficient for such things, but yeah, it doesn't beat not putting it back into the battery in the first place.

It beats the alternative of just changing momentum into heat through friction brakes. In most real world driving, stopping is regularly required.
 
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