Speak EV - Electric Car Forums banner

1 - 17 of 17 Posts

·
Banned
Joined
·
1,370 Posts
Discussion Starter #1
Just had a thought. As we know models of ICE cars are often marketed and sold with various levels of power for the same engine/trim for customers who want economy or power , or a bit of both.

I.E. BMW, 116D, 118D and 120D. All a 2.0 ltr Diesel engine (same block) but different sized turbos depending if you want slower but more economical (116d) or faster and more juicy (120d).

Almost all EV types have only one power level, fixed KWH / POWER output. All that is optional is trim level.

Is it not possible with EV's for them all to have the same KWH output power but software controling (limiting acceleration) to give slower more economical variants (slower but more range for the same KWH power) or faster more juicy variants (Quicker but less range?)

Or does this not make sense with an EV ?

M
 

·
Registered
Joined
·
18 Posts
I'm not sure. Many EVs have an eco mode limiting power to maximise range, likewise an ability to give it the electric beans.

One thing your post does highlight is how the car is regarded, how we have become conditioned to what the car 'is'. EVs may require us to rethink how we 'consume' the car.

(This is the rational behind my PhD, btw... :))
 

·
Premium Member
Joined
·
1,579 Posts
Is it not possible with EV's for them all to have the same KWH output power but software controling (limiting acceleration) to give slower more economical variants (slower but more range for the same KWH power) or faster more juicy variants (Quicker but less range?)

Or does this not make sense with an EV ?
M
Current EVs offer a number of different 'modes' which restrict power, acceleration and provide different levels of regen braking. It's all included as standard.

Many models though (i3 and LEAF excepted) offer only one trim/equipment level, which is usually quite a high spec, maybe higher than the average hatchback buyer would choose. I'm thinking of e-UP, e-Golf and Zoe.
 

·
Registered
Joined
·
7,609 Posts
Just had a thought. As we know models of ICE cars are often marketed and sold with various levels of power for the same engine/trim for customers who want economy or power , or a bit of both.

I.E. BMW, 116D, 118D and 120D. All a 2.0 ltr Diesel engine (same block) but different sized turbos depending if you want slower but more economical (116d) or faster and more juicy (120d).

Almost all EV types have only one power level, fixed KWH / POWER output. All that is optional is trim level.

Is it not possible with EV's for them all to have the same KWH output power but software controling (limiting acceleration) to give slower more economical variants (slower but more range for the same KWH power) or faster more juicy variants (Quicker but less range?)

Or does this not make sense with an EV ?

M
Being pedantic kWH isn't power it is energy. KW is power.

In terms of model segmenting, Tesla Model S can come in 3 configurations (in the UK) a 60, an 85 and a P85

Both 85's have the same amount of energy storage capacity (85kWH), and the 60 only 60kWH. Think of this as how big the fuel tank is.

The P85 has something like 310kW (or 416 BHP), the regular 85 270kW (362 BHP), the 60 225kW (302 BHP).

So a P85 would drain it's 85kWH of stored energy if driven at it's full power of 310 kW in a little over 15 minutes (85kWH/310kW).

A regular 85, something like 18 minutes.

In practice, driving on regular roads at identical speeds/accelerations, both would use exactly the same amount of power to keep up with traffic flow / speed limits, so have identical range.
 

·
Registered
Joined
·
313 Posts
Ampera / Volt also have a selectable mode - Sport or Normal - but that just changes the pedal mapping to give torque sooner. As has been observed previously limiting maximum power level does still to influence range since most driving doesn't approach maximum power.

Regular cars often provide lower power levels for insurance purposes, and they don't necessary have any hardware difference.
 

·
Leaf lover
Joined
·
4,605 Posts
Motor Company A brings out an entirely new car i.e. it does not resemble any other vehicle in their model line-up.
So how do you want it described to you?
Power source
i.e. 100% electric, Electric with Rex, Petrol/hybrid, etc.
Body style.
Number of seats.
Performance (torque factor)
Range (battery capacity)
Weight.
Charging capability
And purchasing options
 

·
Registered
Joined
·
8,106 Posts
@Simon Mac Sorry Simon... I couldn't resist :p

In actual fact, you see it written in all combinations of upper and lower case and even Wikipedia isn't consistent. Normally I wouldn't have mentioned it as we all know what we mean but the "Being pedantic..." was just begging for it :)
 

·
Registered
Joined
·
313 Posts
Motor Company A brings out an entirely new car i.e. it does not resemble any other vehicle in their model line-up.
So how do you want it described to you?
Power source
i.e. 100% electric, Electric with Rex, Petrol/hybrid, etc.
Body style.
Number of seats.
Performance (torque factor)
Range (battery capacity)
Weight.
Charging capability
And purchasing options
For a start I'd want manufacturers to use a consistent set of industry standard terminology and not keep making it up.

Where is the boundary between a series hybrid and a battery electric vehicle with a range extender? Can a vehicle with a mechanical connection between the ICE and the wheels ever be range extended? PHEV, RE-EV, BEVx, REx ..
 

·
Registered
Joined
·
8,106 Posts
I do agree... standard termonolgy would help a lot.

Your post is a great example of how misunderstandings occur because a series (or serial) hybrid is any EV that has an ICE that has no connection to the wheels.... by definition, an EV with a mechanical connection between the ICE and the wheels is already a hybrid so it is already range extended... PHEV & RE-EV mean the same thing and I have never heard of BEVx!

All as I understand it BTW!!!!!
 

·
Registered
Joined
·
313 Posts
I do agree... standard termonolgy would help a lot.

Your post is a great example of how misunderstandings occur because a series (or serial) hybrid is any EV that has an ICE that has no connection to the wheels.... by definition, an EV with a mechanical connection between the ICE and the wheels is already a hybrid so it is already range extended... PHEV & RE-EV mean the same thing and I have never heard of BEVx!

All as I understand it BTW!!!!!
BEVx is one of the minority with a legal definition (in California) - it's a BEV with a range extender but the range-extended range cannot exceed the electric-only range, and the battery must be exhausted before the range extender starts. It's thus directed more towards emergency or occasional use than the likes of an Ampera.

An Ampera / Volt is thus NOT a BEVx, and nor is a European spec i3 Rex because the driver can start the ICE before the battery is exhausted, although the Californian one (with fewer user-selectable modes) is.

European regulations don't distinguish between any of them.
 

·
Registered
Joined
·
3,188 Posts
As I understand it, with an electric motor limiting it's maximum power won't actually make it go further. Flat out it will but used at the same power levels it will use the same power.
Let's take the BMW as an example. The 116d shares a lot of bits with the 120d but there are quite a few changes which make it slightly more efficient at low loadings. Smaller injectors, smaller turbo, different porting, different gear ratio's, etc. If it was just a toned down 120d it would get exactly the same mpg at the same power output but it doesn't.
Same goes for electrics. Let's take the leaf - whatever max power the motor can put out it doesn't change how efficient it is at low loadings. Now a leaf light or whatever could use a motor with different design that was more efficient at lower power to achieve similar results to the 116d - less power but less consumption too.

Of course this is all in ideal test conditions. In reality the more powerful engine will be using less of it's potential more often so will usually be very close on efficiency anyway for a load more power. I don't know how that translates to electric motors but I would presume it's not far off the same.
More efficient design and better tolerances will usually make more difference than simply turning the power down.
 

·
Registered
Joined
·
175 Posts
I think the "Eco" modes on EVs are mainly for the benefit of drivers new to electric who haven't mastered the different driving style - i.e. those more likely to avoid coasting, and make sudden acceleration and braking. For them Eco modes do help by allowing them to do that without the car's computer taking their commands literally and so burning through all the juice.

As for marketing, I do think the manufacturers are approaching it from the wrong angle. Some tangible benefits and overlooked in favour of focusing solely on the environmental benefits - which are important to most current EV drivers, but is pretty much preaching to the converted. Some focus could be put on:

  • Comfort - Virtually no engine noise, no engine vibrations. Quiet, smooth rides.
  • Easy to drive - No gears, less braking - one pedal driving in most situations.
  • High reliability / low maintenance - Few moving parts, extremely simple motor, no complex gearbox. No dirty oil and radiator checks. Little to go wrong and cheap to look after.
  • Home charging - Leave with a "full tank" every morning at next to no cost.
  • Pre-conditioning - Get into a warm, demisted car, and go.
 
1 - 17 of 17 Posts
Top