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Pure BEV Dogma
- Thread starter bonnie
- Start date
JRP3
Hyperactive Member
In this rather low information density video we see a prime example of the confusion caused by including the Volt in the EV category. It's described as a pure EV along with the Tesla and LEAF that will have significantly reduced ranges that they can be driven in the cold before they have to be recharged. The whole point of the Volt design was of course to avoid the range issue.
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And "plug-in hybrid with a cool, but short-lived driving mode" isn't descriptive enough? Do we really need to create more acronyms? How about PIHWACBSLDM?
Duckjybe
Member
Nowhere in the video does he describe the Volt as pure EV. He was simply talking about the EV side of the Volt. And he did not lump the Volt in with the regular hybrids like the Prius which was proper.
JRP3
Hyperactive Member
Direct quote:
He's calling the Volt an all electric car and saying it's going to have significantly reduced range in the cold. Both statements are false.
He's calling the Volt an all electric car and saying it's going to have significantly reduced range in the cold. Both statements are false.
Duckjybe
Member
Sorry I missed the word "all" as in "all electric". Without that word his statements would be totally correct. He's obviously talking about range on battery being reduced.
Yes! But I think we are making very slow forward progress in spite of the often repetitive arguments.
There is another less marketing oriented and more regulatory way to distinguish between a PHEV and an EREV.
If the capacity of the battery must be maintained over a regulated period (ie 10 years) then it is a PHEV as the motor dictates what range is allowed by the battery.
vs
If the capacity of the battery is allowed to wear (reduce) then it is an EREV, as the electric nature of the vehicle is not hidden by having an engine.
Full PHEVs like the Volt, Karma etc are PHEVs because the existence of the motor reduces the allowable SOC swing at purchase (so to guarantee a 10 year life)
The Volt would be an EREV if it allowed a full SOC swing, i.e. 16kWh out of its battery, but it doesn't so it is an PHEV-40 instead of an EREV-60.
Its just a software setting, but it makes the difference.
If the capacity of the battery must be maintained over a regulated period (ie 10 years) then it is a PHEV as the motor dictates what range is allowed by the battery.
vs
If the capacity of the battery is allowed to wear (reduce) then it is an EREV, as the electric nature of the vehicle is not hidden by having an engine.
Full PHEVs like the Volt, Karma etc are PHEVs because the existence of the motor reduces the allowable SOC swing at purchase (so to guarantee a 10 year life)
The Volt would be an EREV if it allowed a full SOC swing, i.e. 16kWh out of its battery, but it doesn't so it is an PHEV-40 instead of an EREV-60.
Its just a software setting, but it makes the difference.
ChadS
Last tank of gas: March 2009
That's a very interesting thought, renim. I agree that many very interested in the EV aspect would love full access to PHEV batteries.
However, I believe PHEVs have a regulatory problem that BEVs don't have. In a BEV, there is no regulation saying you can't let the battery degrade, so automakers give "full" (not really, they hide some of the capacity too) access to the battery. But in a PHEV, the battery is considered part of the emissions system because it affects the mpg rating...so it has to be warranted to perform the same for 10 years and 150k miles. So PHEV manufacturers are forced to build in a bigger buffer.
I haven't actually read the regulations though, so not sure if there's a way around it...
However, I believe PHEVs have a regulatory problem that BEVs don't have. In a BEV, there is no regulation saying you can't let the battery degrade, so automakers give "full" (not really, they hide some of the capacity too) access to the battery. But in a PHEV, the battery is considered part of the emissions system because it affects the mpg rating...so it has to be warranted to perform the same for 10 years and 150k miles. So PHEV manufacturers are forced to build in a bigger buffer.
I haven't actually read the regulations though, so not sure if there's a way around it...
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If anyone is "enjoying" this thread, they may find this discussion of PiP EV range interesting:
Plug-in Toyota Prius, Setting The Record Straight!
I did not see a good explanation of the EPA 6 EV miles vs. 11 gas+electric miles, which was the main point, but good discussion of PiP vs Energi vs. Volt capabilities. Also a comment from Jay Cole about future CARB requirement of at least 10 EV miles for PHEVs.
GSP
Plug-in Toyota Prius, Setting The Record Straight!
I did not see a good explanation of the EPA 6 EV miles vs. 11 gas+electric miles, which was the main point, but good discussion of PiP vs Energi vs. Volt capabilities. Also a comment from Jay Cole about future CARB requirement of at least 10 EV miles for PHEVs.
GSP
The article claims the PiP uses 3.4 of the 4.4 kWh battery but that's just wrong. It actually uses about 2.75 kWh of the battery and it only takes about 3 to 3.2 kWh from the wall to charge it. I'm not sure where he got 3.4.
The reason for the 6 miles of all electric range is not the motor size (60 kW or 80 hp) but the limited amount of power that can be drawn from the relatively small pack. The maximum battery output is 38 kW (60 hp). The motor is bigger because it gets additional power from the engine via a smaller motor/generator when running in hybrid mode.
It turns out that 38 kW is not enough oomph to keep up the required accelerations on the EPA test cycles used to estimate the AER. The part of the test that pushes it into starting the gas engine is at 6 miles. The gas engine turns back off and the test continues until the gas engine starts again due to the battery running out if charge after a full 11 miles.
gnelson
Member
I will accept the IRS definition for a qualified electric vehicle and ignore those who dogmatically insist that a Chevrolet Volt is not an Electric Vehicle. The IRS will allow me a $15000 tax credit for tax year 2013 for the purchase of my 2014 Volt and my 2013 Tesla Model S P85+.
Qualified Plug-in Electric Drive Motor Vehicle
This is a new vehicle with at least four wheels that:
• Is propelled to a significant extent by an electric motor
that draws electricity from a battery that has a capacity of
not less than 4 kilowatt hours and is capable of being
recharged from an external source of electricity, and
• Has a gross vehicle weight of less than 14,000 pounds.
Qualified Plug-in Electric Drive Motor Vehicle
This is a new vehicle with at least four wheels that:
• Is propelled to a significant extent by an electric motor
that draws electricity from a battery that has a capacity of
not less than 4 kilowatt hours and is capable of being
recharged from an external source of electricity, and
• Has a gross vehicle weight of less than 14,000 pounds.
JRP3
Hyperactive Member
A tax enforcement body is hardly the standard bearer for technical definitions. Here is a different governmental definition of electric vehicle, which plug in hybrids such as the Volt fail to meet:
http://www.gpo.gov/fdsys/pkg/CFR-2011-title10-vol3/xml/CFR-2011-title10-vol3-part474.xml
Since plug in hybrids can draw energy from the ICE generator they don't fit the definition of electric vehicle. Since they obviously use two different systems, ICE and electric, they clearly fit the definition of hybrid:
http://dictionary.reference.com/browse/hybrid
The Fisker Karma is basically an EV with a Range Extender, very much like the Chevrolet Volt. The petrol engine can’t transfer power directly to the wheels. It can either charge the battery pack or give power to a generator who adds his power in Sport Mode. There is no separate gearbox or drivetrain for the petrol engine.
The i8 can be driven in EV mode and petrol mode and combined. Moreover since the petrol engine is a lot more powerful than the EV you can charge the battery on the Autobahn and then drive in pure EV mode through town without actually charging the battery through the socket. Therefore the actual EV range is a lot more than the claimed 37km.
When both engines are used the performance is pretty similar to the Model S up to 100mph, above that the i8 is a lot faster up to a limited top speed of 250 km/h. Of course the power delivery is constant, so the i8 will not give up after 2 corners on a race track like the Tesla. The BMW’s 3 cylinder unit is extremely efficient. There is a 10hp micro generator attached to it, therefore the i8 can regenerate energy on both axles front and rear. If you calculate a carbon footprint for the i8 including the energy used during production the car is in a league of its own. I believe from an environmental point of view this construction is better than a pure EV. I know that many Tesla folks will see that differently.
And furthermore, despite having 2 gearboxes and 2 engines the car is 800kg lighter than a Fisker Karma and 100kg lighter than a Corvette.
The i8 can be driven in EV mode and petrol mode and combined. Moreover since the petrol engine is a lot more powerful than the EV you can charge the battery on the Autobahn and then drive in pure EV mode through town without actually charging the battery through the socket. Therefore the actual EV range is a lot more than the claimed 37km.
When both engines are used the performance is pretty similar to the Model S up to 100mph, above that the i8 is a lot faster up to a limited top speed of 250 km/h. Of course the power delivery is constant, so the i8 will not give up after 2 corners on a race track like the Tesla. The BMW’s 3 cylinder unit is extremely efficient. There is a 10hp micro generator attached to it, therefore the i8 can regenerate energy on both axles front and rear. If you calculate a carbon footprint for the i8 including the energy used during production the car is in a league of its own. I believe from an environmental point of view this construction is better than a pure EV. I know that many Tesla folks will see that differently.
And furthermore, despite having 2 gearboxes and 2 engines the car is 800kg lighter than a Fisker Karma and 100kg lighter than a Corvette.
Does the car have a gearbox for the petrol engine yes or no?
Get YOUR facts straight.
The Karma is a serial hybrid.
The i8 is a through-the street parallel hybrid with a second, smaller not-through-the-street electric generator/motor.
The Volt was discussed before in length and it has everything you could think of in a hybrid drive train, except AWD. :wink:
The i8 is a through-the street parallel hybrid with a second, smaller not-through-the-street electric generator/motor.
The Volt was discussed before in length and it has everything you could think of in a hybrid drive train, except AWD. :wink:
Err, no. Power generated by the gasoline engine is not and should not ever be counted into the EV range. Only electricity that you get from the grid can be zero-emission.
This depends utterly on what source of electricity you are using and your usage pattern.
A person that drives a Model S 200 miles every day and recharges using 100% renewable sources, will cover 73,000 miles/year with zero emissions. A person that drives an i8 200 miles every day and recharges using 100% renewable sources, will cover ~7,000 miles/year with zero emissions and 66,000 miles/year at maybe 50 MPG.
The 1300 gallons of gasoline consumed each year will more than drown out the additional environmental cost of making the bigger battery for the Model S.
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