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Discussion Starter #1
My new 2012 Volt regularly and consistently indicated that it burned 10.2 kw-hrs per charge. It almost never varied. Then it was smashed up and the insurance company wrote it off. (Nobody was hurt in the accident.)

So I bought a new 2015 2 years ago to replace it. It also regularly and consistently indicates that it burns 10.2 kw-hrs per charge. And it gets the same distance per charge as the 2012. On average, both cars are being driven the same way over exactly the same terrain and in the same weather.

Both cars deliver 66-68 km max in perfect summer weather and 35-40 km max on very cold Toronto winter days.

I feel quite disappointed that the 2015 is not better than the 2012, given it has a bigger battery. Should I just accept this or do I have a case to take to GM?
 

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I suspect you are thinking about the difference between the Gen 1 and Gen 2 Volts. The higher capacity Gen 2 Volt battery did not start till year 2016.
 

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Discussion Starter #3
M
I suspect you are thinking about the difference between the Gen 1 and Gen 2 Volts. The higher capacity Gen 2 Volt battery did not start till year 2016.
That is not correct. The 2012 and 2015 have 16 and 17.1 kw-hr batteries respectively.
 

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It's slightly low, but in the ballpark for 'normal'. I'd expect a typical range of 10.4-11.1 for the 2015s, but lower is not unusual unless you're talking way less, like <9.

Make sure your car is actually fully charged each time you use it - it may need to relearn the start and stop points to squeeze every bit out of it.
Have you never seen higher than 10.2, even brand new two years ago?
 

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2012 must use more of the battery-lower SOC than the 2015. Cars were rated at 35 miles (2012) and 38 miles (2015) by EPA. However 2015 battery is 17.1kw-hr. The 38 mile rating is from the 2013-2014 cars that had a 16.5kw-hr battery. They never had the larger 2015 battery certified- it would have been 41 miles. But since they had a new Gen2 coming out that did 53 miles, 38 versus 53 sounds better than 41 versus 53.
 

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first gen had 16 then there was a 16.5 (2013) ?? some pre 2013 people say they got a 16.5 as well.
 

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The 2011/2012 Volt battery had a 16.0 kWh capacity, the 2013-14 models increased that to 16.5 kWh, and the 2015 Volt came with a 17.1 kWh battery. Using an "ideal" 65% SOC window, the available power for the Gen 1 models amounted to 10.4 kWh, 10.7 kWh, and 11.1 kWh.

IOW, the mathematically-calculated obtainable full-depletion difference between a 2012 Volt and a 2015 Volt is ~0.7 kWh per charge. That’s really not much... and if your 2012 Volt was a later model with the 16.5 kWh battery, the difference drops to ~0.4 kWh per charge.

The 10.2 kWh per charge readings (even when it was new?) for a fully depleted 2015 battery do seem a tad low, but battery degradation is not the only explanation. Even with a fully functional battery, there are many factors influencing the point at which the computer switches the Volt to Extended Range operation because the minimum SOC has been reached, as well as influencing the accuracy of the calibration of the Battery State Estimate algorithm used to estimate the SOC. Thus it’s difficult to determine why both of your Volts were switching to ICE at about the same amount of kWh Used. Have you tried using an OBD2 reader and an app (Torque, MyGreenVolt) to read your battery’s fully charged and fully depleted raw SOC readings to determine the size of your usable power SOC window?
 

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Discussion Starter #9 (Edited)
It's slightly low, but in the ballpark for 'normal'. I'd expect a typical range of 10.4-11.1 for the 2015s, but lower is not unusual unless you're talking way less, like <9.

Make sure your car is actually fully charged each time you use it - it may need to relearn the start and stop points to squeeze every bit out of it.
Have you never seen higher than 10.2, even brand new two years ago?
How do you relearn the start and stop points? I have fully discharged and fully charged a number of times.

Yes I hit 11.1kw-hrs the first and second full charges 2 years ago when the car was new. It has been 10.2 since then.
 

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Discussion Starter #10
Have you tried using an OBD2 reader and an app (Torque, MyGreenVolt) to read your battery’s fully charged and fully depleted raw SOC readings to determine the size of your usable power SOC window?
No I have not but that sounds like a good idea. Thanks!
 

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Discussion Starter #11
It's slightly low, but in the ballpark for 'normal'. I'd expect a typical range of 10.4-11.1 for the 2015s, but lower is not unusual unless you're talking way less, like <9.
Yes, I realise that I do not have a warranty claim but I am still disappointed and wondering what I can do about it, if anything.
 

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How do you relearn the start and stop points? I have fully discharged and fully charged a number of times.

Yes I hit 11.1kw-hrs the first and second full charges 2 years ago when the car was new. It has been 10.2 since then.
Let the battery drain right down until switchover.
Leave the vehicle parked, unplugged for 2h.
It should have recalculated the battery SOC by then.
You can then fully charge to completion.
Unplug it to wake the computer, then leave it for 2h again to ensure it has recalculated SOC.

Repeat 6-10 times until it returns to expected levels.

If you have OBD you can confirm it is actually charging completely and discharging completely by reading the raw SOC values (or generic "Hybrid battery charge" value).
Full empty is ~19% and normal full charge is ~83.5%.

These numbers should not change much after the 2 hour waits if the calibration is decent (you may need to wake or start up the car to get the most recent value)

If it is fully charging (and the computer recognizes it all), the other possibility is battery temp - if you aren't back to 15C+ battery temp by the time it hits 'empty', you didn't get all the energy out that you put in. "Full" was at 15-25C and then it cooled off, meaning it is no longer "full".
Conversely if you had topped off at a cold temp and it warmed up, you'd actually get more energy out than usual.
 

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Repeat 6-10 times until it returns to expected levels.
Replace and Program ECU or Reprogram ECU
To program a replacement or an existing ECU, perform the following procedure:
1. Install EL-49642 SPS programming support tool.
2. Access the Service Programming System (SPS) and follow the on-screen instructions.
3. On the SPS Supported Controllers screen, select Hybrid Powertrain Control Module 2 - Programming and follow the on-screen instructions.
4. At the end of programming, choose the "Clear All DTCs"
5. With a scan tool, perform the Hybrid/EV Battery Pack Data Reset
6. With a scan tool, perform the Hybrid/EV Battery Pack Capacity Learn
7. With a scan tool, perform the Hybrid/EV Battery Pack Coolant Control Solenoid Valve Learn
8. With a scan tool, perform the Clear Secured High Voltage DTCs




FWIW: Performing the Hybrid/EV Battery Pack Capacity Learn procedure on your Gen1 could be another possible option but would require GDS2!;)
 

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The 2011/2012 Volt battery had a 16.0 kWh capacity, the 2013-14 models increased that to 16.5 kWh, and the 2015 Volt came with a 17.1 kWh battery. Using an "ideal" 65% SOC window, the available power for the Gen 1 models amounted to 10.4 kWh, 10.7 kWh, and 11.1 kWh.

IOW, the mathematically-calculated obtainable full-depletion difference between a 2012 Volt and a 2015 Volt is ~0.7 kWh per charge. That’s really not much... and if your 2012 Volt was a later model with the 16.5 kWh battery, the difference drops to ~0.4 kWh per charge.

The 10.2 kWh per charge readings (even when it was new?) for a fully depleted 2015 battery do seem a tad low, but battery degradation is not the only explanation. Even with a fully functional battery, there are many factors influencing the point at which the computer switches the Volt to Extended Range operation because the minimum SOC has been reached, as well as influencing the accuracy of the calibration of the Battery State Estimate algorithm used to estimate the SOC. Thus it’s difficult to determine why both of your Volts were switching to ICE at about the same amount of kWh Used. Have you tried using an OBD2 reader and an app (Torque, MyGreenVolt) to read your battery’s fully charged and fully depleted raw SOC readings to determine the size of your usable power SOC window?
Both of mine are 2013 and I never got 10.7. Sometimes 10.4 but mostly 10.2. Sometimes it even dipped below 10.
 

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1. Stick a black piece of electrical tape over the "kWh used" portion of the energy screen
2. Install 18" rims with higher performance tires
3. Drive like Jeff Gordon instead of like a grandpa
4. Take on any and all pony cars and ricer boys at stoplights
5. Smile ear to ear while doing this
 

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1. Stick a black piece of electrical tape over the "kWh used" portion of the energy screen
2. Install 18" rims with higher performance tires
3. Drive like Jeff Gordon instead of like a grandpa
4. Take on any and all pony cars and ricer boys at stoplights
5. Smile ear to ear while doing this
Say no more! Say no more!
 

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Discussion Starter #18
1. Stick a black piece of electrical tape over the "kWh used" portion of the energy screen
2. Install 18" rims with higher performance tires
3. Drive like Jeff Gordon instead of like a grandpa
4. Take on any and all pony cars and ricer boys at stoplights
5. Smile ear to ear while doing this
Well, yes. But I'd like to get 11kw-hrs so I can do this for longer :)
 

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