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Discussion Starter · #1 · (Edited)
Okay, I know the mileage my volt shows me is an estimate but there is something I can not understand.

My situation is as follows:

Up until Dec 4th, I was driving my volt almost exclusively. My better half has only driven it may be 2 or 3 days when I needed her car to haul something. My full battery charge was showing me 41-to-44 miles every morning I turned it on around 5:15 AM. My one way commute is ~40 miles and I could do it without the ICE kicking in.

Dec 4th, I left town to go on a business trip and told my fiancee to drive the volt to save on the gas cost and not needing to go to the gas station. He took me up on my offer and drove the volt for 2 weeks. Her commute is only 11-12 miles one way. So, her driving did not need to dip into the gas tank at all, for the whole 2 weeks time.

For the past 2 weeks I Am again the sole driver of the vehicle. But every morning I turn on the car and see 33-35 mile maximum range. As if charging the battery is getting cut off earlier than what it was last month. Example: Last month, I used to come home around 6 PM and plug in the charger in high current mode and the display used to show my battery will be full about 5:10 AM in the morning. Lo and behold, I used to see 42 miles range on display at 5:15 AM. Last night, I came home at 6:25 PM, changed the charging to high current mode and saw that my battery will be full at 4:14 AM. I plugged it in. This morning, when I left home at 5:15 AM, I only had 33 miles of driving range. And these numbers are not ephemeral. Like when I see it 33 and drive as my usual self, I could make it to the end of my trip without ICE kicking in. I am running the ICE for the last 7-8 miles of my trip every day, for the past two weeks.

Can anyone explain why I am experiencing such behavior from my batteries ? I know it is cold(er) outside, but I live in So Cali. Our nightly lowest temperature is still in mid 40's and it was the same way before I left for my trip. Okay may be it was 2-3 degrees higher but it should not cause this big of a dip in my charging levels I am thinking. I am baffled.
 

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Okay, I know the mileage my volt shows me is an estimate but there is something I can not understand.

My situation is as follows:

Up until Dec 4th, I was driving my volt almost exclusively. My better half has only driven it may be 2 or 3 days when I needed her car to haul something. My full battery charge was showing me 41-to-44 miles every morning I turned it on around 5:15 AM. My one way commute is ~40 miles and I could do it without the ICE kicking in.

Dec 4th, I left town to go on a business trip and told my fiancee to drive the volt to save on the gas cost and not needing to go to the gas station. He took me up on my offer and drove the volt for 2 weeks. Her commute is only 11-12 miles one way. So, her driving did not need to dip into the gas tank at all, for the whole 2 weeks time.

For the past 2 weeks I Am again the sole driver of the vehicle. But every morning I turn on the car and see 33-35 mile maximum range. As if charging the battery is getting cut off earlier than what it was last month. Example: Last month, I used to come home around 6 PM and plug in the charger in high current mode and the display used to show my battery will be full about 5:10 AM in the morning. Lo and behold, I used to see 42 miles range on display at 5:15 AM. Last night, I came home at 6:25 PM, changed the charging to high current mode and saw that my battery will be full at 4:14 AM. I plugged it in. This morning, when I left home at 5:15 AM, I only had 33 miles of driving range. And these numbers are not ephemeral. Like when I see it 33 and drive as my usual self, I could make it to the end of my trip without ICE kicking in. I am running the ICE for the last 7-8 miles of my trip every day, for the past two weeks.

Can anyone explain why I am experiencing such behavior from my batteries ? I know it is cold(er) outside, but I live in So Cali. Our nightly lowest temperature is still in mid 40's and it was the same way before I left for my trip. Okay may be it was 2-3 degrees higher but it should not cause this big of a dip in my charging levels I am thinking. I am baffled.
Electric cabin heating can use a significant amount of energy and reduce your driving range. It takes a fair amount of heating to bring up the temperature of a "cold-soaked" car but after than the energy needed to maintain a comfortable temperature is quite a bit less. If you take shorter trips then a larger percentage of the trip is spent running the heater at maximum output so driving is less efficient overall. Therefore, the reduced per mile efficiency from her last 2 weeks is still being used by the car to estimate your driving range and that results in lower estimates. What really matters is the actual driving range that you get. After driving your usual longer and thus more heating-efficient winter route you should see the estimate begin to reflect your own driving pattern again.
 

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Running the heater/defrosters at all will push your miles per kWh down.

And, you've guessed right, the EV battery does not hold as much power when it's cold. Rolling resistance of the tires climbs as well. If you raise the tire pressure to compensate, this can increase stopping distance.

However, unlike battery-only EVs it's not a big deal. The winter drop range won't force you to stop and recharge, or go home on a tow truck.

It has also been fairly windy lately, which can greatly affect range.
 

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Discussion Starter · #5 ·
I understand the affect of HVAC but why does my charging stop about an hour early, assuming the car is fully charged while it was running that extra hour about a month ago ? I never come home with any smidgen of charge left in the battery. So, my driving habits can not be the answer to that. Last night, I came home with and empty battery, about half an hour later than my usual and it still suggested that my charging will be an hour less than what it was, a month or so ago. I am trying to make the heads or tails of this situation.
 

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Key factors in battery usage are;

  • Ambient temperature
  • Use of HVAC controls
  • Weather (rain, snow, etc)
  • Human driving habits
These are your answers.
 

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I understand the affect of HVAC but why does my charging stop about an hour early, assuming the car is fully charged while it was running that extra hour about a month ago ? I never come home with any smidgen of charge left in the battery. So, my driving habits can not be the answer to that. Last night, I came home with and empty battery, about half an hour later than my usual and it still suggested that my charging will be an hour less than what it was, a month or so ago. I am trying to make the heads or tails of this situation.
(1) Is the clock on your Volt correct?
(2) The charging time is an estimate and could be related to estimated energy needed to condition the battery. Since you are now running the engine at the end of your trip, the residual warmth might help by reducing the estimated conditioning overhead.

On the point of range:
If you are concerned whether the battery is charging fully, use the Energy Info (Press Leaf button, press Energy Info tab at top right of screen) screen before you leave and after you return to see how many kWh you used and how many miles EV you drove. The numbers reset after a full charge. So:
- In the morning you should see it reset to 0kWh and 0 miles.
- When you complete the leg of your commute you should see something like 10kWh for a 2011-2012, 10.5 for 2013-early 2014, and 10.9(?) for late 2014-2015.
 

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I understand the affect of HVAC but why does my charging stop about an hour early, assuming the car is fully charged while it was running that extra hour about a month ago ? I never come home with any smidgen of charge left in the battery. So, my driving habits can not be the answer to that. Last night, I came home with and empty battery, about half an hour later than my usual and it still suggested that my charging will be an hour less than what it was, a month or so ago. I am trying to make the heads or tails of this situation.
You are going to have to get more specific.

If it charges from 0 kWh to 10.8 kWh in 3 hours at 240.0 vac on L2 charging at 16 amps, yes there is something wrong.

If you are using the factory 120v cable at 8 amps, instead of 12, things change wildly. If your house has 105vac measured at the outlet in the summer, but 124 vac measured in the winter, ditto.
 

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Can anyone explain why I am experiencing such behavior from my batteries ? I know it is cold(er) outside, but I live in So Cali. Our nightly lowest temperature is still in mid 40's and it was the same way before I left for my trip. Okay may be it was 2-3 degrees higher but it should not cause this big of a dip in my charging levels I am thinking. I am baffled.
A full charge is represented by 10 green bars of power on the display. How far you drive on that power depends on your driving habits, the environment, and the terrain. What you seem to be facing is the seasonal drop in range, magnified by the influence of a "temporary driver’s" two weeks of driving data on the calculation of the full charge range estimate.

1. Effect of a second driver on full charge estimated range

If you normally drive ~40 electric miles using 10 kWh of power (most of the available power), your full charge range estimate will tend to be ~40+ miles. At that rate, you would tend to use ~5 kWh of power to drive 20 miles.

If your fiancee is a lead-foot driver who really likes to turn up the heat, she might have used up 10 kWh for her ~20+ mile round trip commute. That’s a mileage rate just about half of yours. Eventually her full charge estimate would tend to be ~ 20+ miles. Multiplying mileage obtained while driving in electric mode by amount of power in a full charge gives estimated distance.

Now that you are again driving the car, the algorithm that calculates the full charge estimate is combining the recent data from your driving with the data gathered while she was driving, to produce an estimate that is lower than your previous numbers, but above what hers would have become given time (i.e., somewhere between 20+ and 40+). The numbers should increase as her previous data moves further into the past and your data is again providing the bulk of the data used for the calculation... except for the fact that the seasons have changed...

2. Seasonal changes in full charge estimated range

It takes time to gain a sense of when and how far the seasonal fluctuations will go up and down on the full charge range, and you’ve only owned the car since last July. As someone above has pointed out, now that you arrive home after using the ICE, it might reduce the power consumption needed to condition the battery as you charge, thus shortening the estimated completion time. It appears you are using 120 volt charging, so a reduced need for power to maintain conditioning could produce an observable shortening of charging time. One year is rarely identical to the next in terms of daily temperatures and precipitation levels, producing increasing or decreasing needs to use battery power for accessories at different times in the month from one year to the next, reducing or increasing range. Changing length of day and night also impacts the use of lights and climate control during your commute, impacting range.
 

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Discussion Starter · #11 ·
Thanks for all the explanations. I got most of it. One thing I am not sure is to what temperature the car HVAC was set to. I usually do not mess with it. Unless it is a scorcher outside, like the time I newly acquired this car, I usually use a low speed, fan only A/C with intermittent refrigeration. Having said that, my fiancee being a born and raised Southern Cali girl, who never lived anywhere else in her entire life, finds 62 degrees temperature "Freezing Cold". So, her setting the temp to a higher level wouldn't be a surprise.

But, after saying this, I realized I have never paid any attention to how the heating works on volt. In my corolla, you have to turn the dial to hotter setting and it basically diverted the air from ICE cooling stream, partially into the cabin. Since there is no ICE running on volt, when I am on EV mode, the only thing I can think of is the little red and blue temperature arrows. Is this how you set the car to heat or cool or is there some other factor. And what happens if I turn off the fan totally and let the air flow happen due to the car's speed. Would it still heat the incoming air, to the set temperature ? If yes, How would I stop that all together ? I mean, I am big guy and volt cabin is small. Probably 5 minutes of huffing and puffing will make the temperature close to what is normal for me (my fiancee may not agree on that but it is besides the matter).
 

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Thanks for all the explanations. I got most of it. One thing I am not sure is to what temperature the car HVAC was set to. I usually do not mess with it. Unless it is a scorcher outside, like the time I newly acquired this car, I usually use a low speed, fan only A/C with intermittent refrigeration. Having said that, my fiancee being a born and raised Southern Cali girl, who never lived anywhere else in her entire life, finds 62 degrees temperature "Freezing Cold". So, her setting the temp to a higher level wouldn't be a surprise.

But, after saying this, I realized I have never paid any attention to how the heating works on volt. In my corolla, you have to turn the dial to hotter setting and it basically diverted the air from ICE cooling stream, partially into the cabin. Since there is no ICE running on volt, when I am on EV mode, the only thing I can think of is the little red and blue temperature arrows. Is this how you set the car to heat or cool or is there some other factor. And what happens if I turn off the fan totally and let the air flow happen due to the car's speed. Would it still heat the incoming air, to the set temperature ? If yes, How would I stop that all together ? I mean, I am big guy and volt cabin is small. Probably 5 minutes of huffing and puffing will make the temperature close to what is normal for me (my fiancee may not agree on that but it is besides the matter).
The HVAC works on a thermostat setting.
You pick a temp number and the car will try to maintain that level using heat, AC, fan only or any combination when you hit the AUTO button.
Fan only will pick up heat from the engine if in use, and it will work similar to your Corolla except the car will do the blending for you. No need to manually select how much or how little heat you want to come out. Just pick a temp and set it.

So if the Mrs. set it to 90 (or just kept hitting red arrow for 'more hot') and hit AUTO, it's going to blast a lot of heat. If the engine is off, that's going to be energy from the battery.

By default my car is always in the closed/recirc airflow setting when HVAC is off.
I have not found a way to leave it on passive flow-through without turning the fan on 1 notch.
 

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Since there is no ICE running on volt, when I am on EV mode, the only thing I can think of is the little red and blue temperature arrows. Is this how you set the car to heat or cool or is there some other factor. And what happens if I turn off the fan totally and let the air flow happen due to the car's speed. Would it still heat the incoming air, to the set temperature ? If yes, How would I stop that all together ? I mean, I am big guy and volt cabin is small. Probably 5 minutes of huffing and puffing will make the temperature close to what is normal for me (my fiancee may not agree on that but it is besides the matter).
Press the climate button on the dash. This takes you to the climate screen. By pressing the red or blue button you will see the temperature setting rise or lower depending on the color. Eventually LOW is the lowest setting and Hi is the highest. Self explanatory.

If you turn the fan off, active heating and cooling will stop in EV mode. If the vent is not set to re-circulate and you are going fast enough, air will flow into the cabin. Some heat will continue into the cabin due to the heater core still being warm until the heater core reaches ambient temperature. But again there is no active electric heating going on and the heater core will cool down.

If you want to stop outside air from moving into the cabin select recirculate (eventually the heater core will cool regardless). All this is pretty standard on any vehicle.

You may want to familiarize yourself with the manual at this point.
 

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My guess is that she was running the heater which reduced the range and the estimate. No big deal of course, but you may want to use the OnStar app to check the SOC after charging. Mine sometimes cuts out early which reduces the available miles.
 

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This is a 2013 right? Anything over 38mi range is gravy. Anything under that is caused by things mentioned in the above discussion.

Drive it for a full year to see what 'normal' is for your use case. Another driver could have significant impact on EV range.

GM was saying 'between 25 and 50' AER for that MY.
 

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Living up the coast a bit from you, we've been getting colder temps the last two or three weeks and that always reduces range as has already been pointed out. The number next to the battery is a prediction of range that is determined as others have said, but if memory serves--which it rarely does--they didn't mention tire pressure, which is also impacted some by temperature.

Bottom line from all this is that you could check a couple things like what your climate settings are and your tire pressures, but odds are nothing is more wrong than that.

I'm not sure what the issue is with charge times but it probably isn't anything wrong with the car, battery, or charger.
 

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Even though you live in socal, your battery is sensitive to the cooler climate, and will be affected
I also live in a warm State (Florida)
And my 2015 volt is affected by the weather
In the HR hot summer climate I average 53+ ev miles per full charge
In the cooler weather I only get about 40 ev miles.
It is normal, just live with it, and enjoy your volt
Happy new year!!!!
 

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I agree with the assessment of others, sounds normal.

I just got my 2012 Volt about 5 months ago. When fully charged the calculated range was around 38 miles. After having driven it for a few months that number slowly crept up to 48 miles. I only have a ~13 mile total daily commute with mostly 2-lane country roads, no highway, maximum speed limits around 30 to 45 mph and minimal stops. The previous owner often had an hour+ mostly highway commute which explains the lower calculated range when I first got it. Even if I do some highway driving on the weekend and consume the battery faster than the calculated range, one weekend is not enough to have a noticeable impact on my 48 mile calculated range.

I have recently made several longer drives now (about 75 miles one-way) where I was only able to get ~40 highway miles on electric before the ICE kicked in. In combination of that and the colder weather, (not using the heater, only using heated seats) the calculated range has dropped as low as 36 miles.

I can definitely see how another driver for 2 weeks and colder temps could impact your calculated range and will remain that way for some time, but should not affect your driving range. I think your reduced range is most likely due to the cooler weather, but there may also be a setting with the heater that was left on by the other driver that you have not switched back to the mode you typically use. Make sure you have it set to Fan only and check the tire pressures.

I've also noticed once after plugging in the included charger at 12A with a fully depleted battery, after a decently long period of time (maybe just under an hour?) the calculated range was just 1 mile. It seems, as others have mentioned, it must pre-condition the battery before it begins charging so the shorter charging time might just mean the conditions were closer to optimal when you experienced a shorter charge time than when you see a longer charge time. Winter in Texas is generally very mild, but still enough to have a significant impact on range even without use of the heater.
 
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