[jljonathan]

2018 volt when I fully charged (the green blinking light is on full) the car brand new, on different days there can be different ev ranges displayed. Last week it was 63, this week 57or58. Why is there a difference?

Also, sometimes when I start right after a full charge (ev range 58) in a mile or so it goes down to 48 and stays there until the driving catches up to the 48, then it goes down mile by mile. Why?

 

[Steverino]

It's an estimate not a meter. It's based on your past driving history. Drive like a hot rodder and the estimated range will drop. Drive like an old lady and it will increase.

It will also drop based on hills, rain, snow, heater use, low tire pressure. highway driving.

 

[sosmerc]

The EV "guesometer" relies heavily on your driving habits on the previous usage after a full charge. It also takes into account for outside temp and your climate control settings and your terrain. If you drive like an old lady and do not use the gas engine between charges (all in town driving for example, and not exceeding the EV range) your estimated EV range will increase. But if the temp drops and you crank up the heat AND put the petal to the metal and start climbing hills your range will decrease rapidly.

 

[Hexperience]

On your energy information display page it shows how many kWh you have used. That's the true "gas gauge". You will find that at around 14 to 15 kW have been used you are "empty". If you get higher that means you've been good on Regen.

 

[Arcanox]

On your energy information display page it shows how many kWh you have used. That's the true "gas gauge". You will find that at around 14 to 15 kW have been used you are "empty". If you get higher that means you've been good on Regen.

From what I've observed, regen counts negatively towards the kWh used. If you charge fully and drive to empty, regardless of driving habits, it should read almost exactly 14.5 kWh each time. It's measuring the difference in battery SOC between full and empty.

 

[lagagnon]

The answer to the OP's question is really quite well explained in pages 27 and 28 of the manual.

 

[UncleDon]

Maybe so, but the manual is not an excellent source for info

 

[wordptom]

On your energy information display page it shows how many kWh you have used. That's the true "gas gauge". You will find that at around 14 to 15 kW have been used you are "empty". If you get higher that means you've been good on Regen.

I agree with Arcanox. My understanding is the kWh Used number on the energy usage screen shows a net calculation of the amount of grid power used from the battery less the amount of regen put back into the battery while driving on grid power. Regen doesn’t influence the fully depleted kWh Used number.

IOW, a fully charged Volt battery contains a fairly consistent amount of usable power each time you fully charge it. How far you can drive using that grid power depends on your driving habits, and the environment and terrain encountered during the driving. Whenever you slow down on level terrain (coasting in D or L or using the paddle or the brake pedal), the regenerative braking system will brake the car by cranking the motor as a generator, recapturing some of the energy used earlier to accelerate the car. (Downhill regen captures gravitational-sourced energy.)

If you’re driving in Electric Mode, that regen will recharge the battery (sometimes while driving down a long hill you may observe the kWh Used number getting smaller), allowing you to re-use that amount of charge to drive Electric Miles.

If you’re driving in Hold mode or with a fully depleted battery, the regenerative braking system is still working, recharging the battery as it brakes the car. In Extended Range Mode, regen battery power is used to drive Gas Miles.

Presenting the kWh Used as a net calculation of grid power used removes the influence of regen on the fully depleted number. Each time you drive far enough to fully deplete the battery, the kWh Used number should remain about the same, representing the amount of grid power you stored in the fully charged battery.

 

[UncleDon]

Wow wordptom. How did you learn that?

 

[wordptom]

Wow wordptom. How did you learn that?

I’ve been driving my 2012 Volt for 5+ years now, so I’ve spent quite a bit of time trying to understand how Volts operate. I’ve learned lots about my Volt from following and participating in many discussion threads on this forum. The Wikipedia article on the Chevy Volt also provides an accumulation of information, and I particularly like one of the earlier videos in which Pamela Fletcher, who was then the Chief Engineer, Volt Powertrain, explained how the 2011 Volt works to provide "electric-like" driving in Extended Range Mode (http://www.youtube.com/watch?v=d9-9atMw6Zs).

Trying to understand the energy usage display led to the observation (it’s also mentioned in the manual) that the Electric Mode stats (Electric Miles / kWh Used) reflect driving done on battery power put there from the wall plug (i.e., grid power), and Extended Range Mode car stats (Gas Miles / Gas Used) reflect driving done using gas-generated power.

Electric Mode stats reflect the same conditions experienced by any all-electric car (the only fuel is the grid power from the wall that was stored in the battery, plus any regen obtained while driving on grid power). Of course, those cars don’t have the ability to game their stats by switching into gas-assisted driving modes when driving uphill or when driving at highway speeds to save the battery for slow speed driving...

Regenerative braking is another interesting topic. An electric car’s propulsion motor is connected via the drivetrain to the wheels, making an alternative to friction braking possible. The car’s kinetic energy can be used to slow the car, using the rotating wheels of the coasting car to crank the motor/generator to create electricity. Braking the car by recharging the battery provides additional fuel for the electric motor, increasing overall efficiency.

 

[flyingsherpa]

Think of a normal ICE car driving on 1 gallon of gas. Do you always get the exact same distance from that 1 gallon if you drive city vs highway, flat vs mountains, etc? No, of course not. Same with a battery, it depends on where and how you drive (and HVAC use too).

 

[JRRF]

Also, sometimes when I start right after a full charge (ev range 58) in a mile or so it goes down to 48 and stays there until the driving catches up to the 48, then it goes down mile by mile. Why?

No one here has yet to answer one of the OP's questions. Going from 58 to 48 in a mile of driving seems hardly possible unless maybe that mile is being driven uphill at full throttle (which would imply maintaining illegal speeds for quite a bit of it). And then how does the display maintain 48 unless the next several miles are all downhill?

 

[Arcanox]

No one here has yet to answer one of the OP's questions. Going from 58 to 48 in a mile of driving seems hardly possible unless maybe that mile is being driven uphill at full throttle (which would imply maintaining illegal speeds for quite a bit of it). And then how does the display maintain 48 unless the next several miles are all downhill?

If there's almost zero short-term driving habits, but the weather is cold, then the range is going to keep dropping during the cabin warm-up phase as the vehicle detects "wow, we're using way more kWh/mi than we expected!"

Then, once the cabin warms up and the power usage drops way off, the vehicle will detect "woops, now we're hardly using any kWh/mi!" However, the EV range won't go back up unless a significant amount of power is put back into the battery, so it just keeps the range estimate constant until the new estimate starts to drop.

The more driving that occurs in EV mode, the less obvious this will be, because the vehicle will learn the characteristics of cabin heat vs driving style and be able to calculate the range better.

 

[JRRF]

If there's almost zero short-term driving habits, but the weather is cold, then the range is going to keep dropping during the cabin warm-up phase as the vehicle detects "wow, we're using way more kWh/mi than we expected!"

Then, once the cabin warms up and the power usage drops way off, the vehicle will detect "woops, now we're hardly using any kWh/mi!" However, the EV range won't go back up unless a significant amount of power is put back into the battery, so it just keeps the range estimate constant until the new estimate starts to drop.

The more driving that occurs in EV mode, the less obvious this will be, because the vehicle will learn the characteristics of cabin heat vs driving style and be able to calculate the range better.

Ten miles of range is a lot to lose. And this guy lives in LA.

 

[Cobalt60Volt]

2018 volt when I fully charged (the green blinking light is on full) the car brand new, on different days there can be different ev ranges displayed. Last week it was 63, this week 57or58. Why is there a difference?

Also, sometimes when I start right after a full charge (ev range 58) in a mile or so it goes down to 48 and stays there until the driving catches up to the 48, then it goes down mile by mile. Why?

Sounds like you are driving like I do. Drive it like you stole it. My meter dropped from the typical 80-85kms to 64 after giving a few friends a very spirited drive ? it can be very intoxicating. Most fun I have had in a car since my High School days. ?

 

[Arcanox]

Ten miles of range is a lot to lose. And this guy lives in LA.

Same will happen if the A/C is running a lot, or if there's a hill to climb, or if the driver drives "enjoyably" (as I phrase it, and do myself). If there's little to no short term data and you "drive it like you stole it", it's going to overcompensate and drastically drop the range, only to hang on to the same mileage for a while. This happened to me after my HV battery got a segment replaced and they had to reprogram a bunch of modules.

 

[jbakerjonathan]

<snip>

If you’re driving in Electric Mode, that regen will recharge the battery (sometimes while driving down a long hill you may observe the kWh Used number getting smaller), allowing you to re-use that amount of charge to drive Electric Miles.

If you’re driving in Hold mode or with a fully depleted battery, the regenerative braking system is still working, recharging the battery as it brakes the car. In Extended Range Mode, regen battery power is used to drive Gas Miles.

Presenting the kWh Used as a net calculation of grid power used removes the influence of regen on the fully depleted number. Each time you drive far enough to fully deplete the battery, the kWh Used number should remain about the same, representing the amount of grid power you stored in the fully charged battery.

What you have described is what I also believe. So, it is a conundrum that when I look at my energy screen in my 2014 I see, after a 6752 mile road trip, that I have gone 42.5 miles on battery, but used 20.4 kWh to do so. I usually use only ~10.3 kWh. I never plugged in while on the trip. I have to conclude that some of the regen while in CS mode was attributed to electric side of the tally, while the balance was put in the ICE side (increasing the MPG).

I did start out in Hold Mode and gradually used up the battery by forgetting to select Hold mode when starting up and driving a few miles after visiting gas stations,, as well as when going through towns. When in Hold Mode, I would sometimes see a green bar or two in the grayed-out battery symbol that indicated regen adding electons to the battery (after going down hills). My thinking has been that that energy capture was used to (in effect) increase the MPG.

It could be that while adding heat to the cabin while in Hold Mode caused the regen to be applied to the battery expenditure calculation...or something.

Anyone have ideas?

 

[Arcanox]

What you have described is what I also believe. So, it is a conundrum that when I look at my energy screen in my 2014 I see, after a 6752 mile road trip, that I have gone 42.5 miles on battery, but used 20.4 kWh to do so. I usually use only ~10.3 kWh. I never plugged in while on the trip. I have to conclude that some of the regen while in CS mode was attributed to electric side of the tally, while the balance was put in the ICE side (increasing the MPG).

I did start out in Hold Mode and gradually used up the battery by forgetting to select Hold mode when starting up and driving a few miles after visiting gas stations,, as well as when going through towns. When in Hold Mode, I would sometimes see a green bar or two in the grayed-out battery symbol that indicated regen adding electons to the battery (after going down hills). My thinking has been that that energy capture was used to (in effect) increase the MPG.

It could be that while adding heat to the cabin while in Hold Mode caused the regen to be applied to the battery expenditure calculation...or something.

Anyone have ideas?

The only time the "kWh used" would be larger than the size of the usable battery buffer (14.5 kWh in Gen 2, not sure about a 2014) is if the car was plugged in but did not reach a full charge, and was driven further. I've seen values up in the 30s if I'm driving a lot in a day without fully charging the car. The power produced by the engine should never be included in that value.

 

[jbakerjonathan]

The only time the "kWh used" would be larger than the size of the usable battery buffer (14.5 kWh in Gen 2, not sure about a 2014) is if the car was plugged in but did not reach a full charge, and was driven further. I've seen values up in the 30s if I'm driving a lot in a day without fully charging the car. The power produced by the engine should never be included in that value.

I never plugged in for any charge, partial or complete, during my trip, hence a conundrum... until someone comes up with the explanation. I've seen this at the end of other road trips and I have never plugged in on those trips either.

 

[Arcanox]

I never plugged in for any charge, partial or complete, during my trip, hence a conundrum... until someone comes up with the explanation. I've seen this at the end of other road trips and I have never plugged in on those trips either.

Perhaps the Gen 1 calculate kWh used differently than Gen 2; I have no other explanation