Are Electric Cars the biggest con on the planet???
Discussion
ruggedscotty said:
GT9 said:
As you've said, it's important to understand that the power available from the battery is related to its size.
Essentially, for two batteries that have the same voltage rating, the larger one will have a lower internal resistance, which affects the voltage drop (and heating) across the battery.
More current can be drawn from the larger battery, and because they both have the same voltage, this means more powaaa!
The larger battery adds more overall performance because the proportional power increase is far higher than the proportional kerb mass increase.
For extreme performance, a higher battery voltage is very desirable.
What type of battery are you talking about. sometimes the smaller ones pack alot more punch. Being in and around batteries there aere many variables to take into consideration. And its not just the battery that matters but the load too. needs to be matched. Essentially, for two batteries that have the same voltage rating, the larger one will have a lower internal resistance, which affects the voltage drop (and heating) across the battery.
More current can be drawn from the larger battery, and because they both have the same voltage, this means more powaaa!
The larger battery adds more overall performance because the proportional power increase is far higher than the proportional kerb mass increase.
For extreme performance, a higher battery voltage is very desirable.
The higher voltage will only take it so far and then the power will drop. its not cut and dried....
https://nrsyed.com/2018/01/21/how-to-read-a-dc-mot...
What were you thinking?
You've linked to 24V DC motors of a few hundred watts.....
OutInTheShed said:
bigothunter said:
..
Which reinforces my point. Even the base model Golf is laden with trinkets and become bloated over the years.
Base Golf owners are also bloated and loaded with trinkets....Which reinforces my point. Even the base model Golf is laden with trinkets and become bloated over the years.
Small cars are for losers. The bigger the car the bigger the winner. Its the basic rule for the apex consumer.
One thing I am noticing more and more is the inside lane on any motorway or A road seems to be becoming the EV lane. I was trying to join the A3 on Sunday and there was a car on the inside lane just as I was about to join. I was just about to slow down and tuck in behind until I realised it was a Nissan Leaf doing about 50MPH so I just accelerated slightly to give myself some ground and pulled out in front of it.
If you drive a Nissan Leaf, please, please stay at home and don't clog up the inside lane of major roads at 50 MPH or less as you nervously watch the 7% battery remaining warning like a hawk.
If you drive a Nissan Leaf, please, please stay at home and don't clog up the inside lane of major roads at 50 MPH or less as you nervously watch the 7% battery remaining warning like a hawk.
Joey Deacon said:
One thing I am noticing more and more is the inside lane on any motorway or A road seems to be becoming the EV lane. I was trying to join the A3 on Sunday and there was a car on the inside lane just as I was about to join. I was just about to slow down and tuck in behind until I realised it was a Nissan Leaf doing about 50MPH so I just accelerated slightly to give myself some ground and pulled out in front of it.
If you drive a Nissan Leaf, please, please stay at home and don't clog up the inside lane of major roads at 50 MPH or less as you nervously watch the 7% battery remaining warning like a hawk.
Nissan Leaf's are the OAP EV of choice. The same OAP's who have been regularly clogging up the inside lane of the motorway since time immemorial no matter the propulsion method of the vehicle. If you drive a Nissan Leaf, please, please stay at home and don't clog up the inside lane of major roads at 50 MPH or less as you nervously watch the 7% battery remaining warning like a hawk.
Joey Deacon said:
One thing I am noticing more and more is the inside lane on any motorway or A road seems to be becoming the EV lane. I was trying to join the A3 on Sunday and there was a car on the inside lane just as I was about to join. I was just about to slow down and tuck in behind until I realised it was a Nissan Leaf doing about 50MPH so I just accelerated slightly to give myself some ground and pulled out in front of it.
If you drive a Nissan Leaf, please, please stay at home and don't clog up the inside lane of major roads at 50 MPH or less as you nervously watch the 7% battery remaining warning like a hawk.
I find the opposite.If you drive a Nissan Leaf, please, please stay at home and don't clog up the inside lane of major roads at 50 MPH or less as you nervously watch the 7% battery remaining warning like a hawk.
As EV’s are so cheap to ‘fuel’ (home charging) I don’t care too much about economy and am happy to push on. Yet the inside and middle lanes are nose-to-tail ICE cars stretching their fuel MPG’s by driving at 50-60mph.
Often I’m in the outside lane with various EV’s in front/behind me overtaking the chugging ICE’s.
GT9 said:
ruggedscotty said:
GT9 said:
As you've said, it's important to understand that the power available from the battery is related to its size.
Essentially, for two batteries that have the same voltage rating, the larger one will have a lower internal resistance, which affects the voltage drop (and heating) across the battery.
More current can be drawn from the larger battery, and because they both have the same voltage, this means more powaaa!
The larger battery adds more overall performance because the proportional power increase is far higher than the proportional kerb mass increase.
For extreme performance, a higher battery voltage is very desirable.
What type of battery are you talking about. sometimes the smaller ones pack alot more punch. Being in and around batteries there aere many variables to take into consideration. And its not just the battery that matters but the load too. needs to be matched. Essentially, for two batteries that have the same voltage rating, the larger one will have a lower internal resistance, which affects the voltage drop (and heating) across the battery.
More current can be drawn from the larger battery, and because they both have the same voltage, this means more powaaa!
The larger battery adds more overall performance because the proportional power increase is far higher than the proportional kerb mass increase.
For extreme performance, a higher battery voltage is very desirable.
The higher voltage will only take it so far and then the power will drop. its not cut and dried....
https://nrsyed.com/2018/01/21/how-to-read-a-dc-mot...
What were you thinking?
You've linked to 24V DC motors of a few hundred watts.....
The larger battery will have the lower internal resistance ? Nope not always, some of the smaller batteries have a lot lower resistances. And a series parallel combo ? could muster a significant output. Plus your battery chemistry, just how its constructed influences the way it can discharge.Also internal resistance doesnt stay static... So your simplistic view regarding sizes of batteries.. Hmmmmm.....
SDK said:
Joey Deacon said:
One thing I am noticing more and more is the inside lane on any motorway or A road seems to be becoming the EV lane. I was trying to join the A3 on Sunday and there was a car on the inside lane just as I was about to join. I was just about to slow down and tuck in behind until I realised it was a Nissan Leaf doing about 50MPH so I just accelerated slightly to give myself some ground and pulled out in front of it.
If you drive a Nissan Leaf, please, please stay at home and don't clog up the inside lane of major roads at 50 MPH or less as you nervously watch the 7% battery remaining warning like a hawk.
I find the opposite.If you drive a Nissan Leaf, please, please stay at home and don't clog up the inside lane of major roads at 50 MPH or less as you nervously watch the 7% battery remaining warning like a hawk.
As EV’s are so cheap to ‘fuel’ (home charging) I don’t care too much about economy and am happy to push on. Yet the inside and middle lanes are nose-to-tail ICE cars stretching their fuel MPG’s by driving at 50-60mph.
Often I’m in the outside lane with various EV’s in front/behind me overtaking the chugging ICE’s.
Maracus said:
You've just described the M40
The M40 is littered with Tesla's hypermiling. To date it's been Polestar drivers who have stood out among EV users as driving at the appropriate minimum 90mph limit for the Oxford to London section. The M5 between Cheltenham and Bristol is also a common stretch for Tesla's to crawl along as if they can't afford the electricity after stretching themselves for the ultimate driveway chattel.
A lot of EV drivers do come over as the kind of tightwad who goes next door for a dump so as to save on toilet paper costs.
DonkeyApple said:
Maracus said:
You've just described the M40
The M40 is littered with Tesla's hypermiling. To date it's been Polestar drivers who have stood out among EV users as driving at the appropriate minimum 90mph limit for the Oxford to London section. The M5 between Cheltenham and Bristol is also a common stretch for Tesla's to crawl along as if they can't afford the electricity after stretching themselves for the ultimate driveway chattel.
A lot of EV drivers do come over as the kind of tightwad who goes next door for a dump so as to save on toilet paper costs.
DonkeyApple said:
The M40 is littered with Tesla's hypermiling. To date it's been Polestar drivers who have stood out among EV users as driving at the appropriate minimum 90mph limit for the Oxford to London section.
The M5 between Cheltenham and Bristol is also a common stretch for Tesla's to crawl along as if they can't afford the electricity after stretching themselves for the ultimate driveway chattel.
A lot of EV drivers do come over as the kind of tightwad who goes next door for a dump so as to save on toilet paper costs.
haha. my tyres cost more per mile than electricity The M5 between Cheltenham and Bristol is also a common stretch for Tesla's to crawl along as if they can't afford the electricity after stretching themselves for the ultimate driveway chattel.
A lot of EV drivers do come over as the kind of tightwad who goes next door for a dump so as to save on toilet paper costs.
ruggedscotty said:
GT9 said:
ruggedscotty said:
GT9 said:
As you've said, it's important to understand that the power available from the battery is related to its size.
Essentially, for two batteries that have the same voltage rating, the larger one will have a lower internal resistance, which affects the voltage drop (and heating) across the battery.
More current can be drawn from the larger battery, and because they both have the same voltage, this means more powaaa!
The larger battery adds more overall performance because the proportional power increase is far higher than the proportional kerb mass increase.
For extreme performance, a higher battery voltage is very desirable.
What type of battery are you talking about. sometimes the smaller ones pack alot more punch. Being in and around batteries there aere many variables to take into consideration. And its not just the battery that matters but the load too. needs to be matched. Essentially, for two batteries that have the same voltage rating, the larger one will have a lower internal resistance, which affects the voltage drop (and heating) across the battery.
More current can be drawn from the larger battery, and because they both have the same voltage, this means more powaaa!
The larger battery adds more overall performance because the proportional power increase is far higher than the proportional kerb mass increase.
For extreme performance, a higher battery voltage is very desirable.
The higher voltage will only take it so far and then the power will drop. its not cut and dried....
https://nrsyed.com/2018/01/21/how-to-read-a-dc-mot...
What were you thinking?
You've linked to 24V DC motors of a few hundred watts.....
The larger battery will have the lower internal resistance ? Nope not always, some of the smaller batteries have a lot lower resistances. And a series parallel combo ? could muster a significant output. Plus your battery chemistry, just how its constructed influences the way it can discharge.Also internal resistance doesnt stay static... So your simplistic view regarding sizes of batteries.. Hmmmmm.....
Here are the battery ratings for the global EV market in 2023, over 300 different models to choose from.....
Sure, there are some outliers, particularly the stupidly powerful hypercars and the stupidly large battery stuff.
Also some oddballs where smaller batteries have been shoehorned into ICE platforms.
Generally though, you aren't going get a powerful EV without at least 50 kWh under the bonnet and for really big power, 70 kWh is a minimum.
GT9 said:
ruggedscotty said:
GT9 said:
ruggedscotty said:
GT9 said:
As you've said, it's important to understand that the power available from the battery is related to its size.
Essentially, for two batteries that have the same voltage rating, the larger one will have a lower internal resistance, which affects the voltage drop (and heating) across the battery.
More current can be drawn from the larger battery, and because they both have the same voltage, this means more powaaa!
The larger battery adds more overall performance because the proportional power increase is far higher than the proportional kerb mass increase.
For extreme performance, a higher battery voltage is very desirable.
What type of battery are you talking about. sometimes the smaller ones pack alot more punch. Being in and around batteries there aere many variables to take into consideration. And its not just the battery that matters but the load too. needs to be matched. Essentially, for two batteries that have the same voltage rating, the larger one will have a lower internal resistance, which affects the voltage drop (and heating) across the battery.
More current can be drawn from the larger battery, and because they both have the same voltage, this means more powaaa!
The larger battery adds more overall performance because the proportional power increase is far higher than the proportional kerb mass increase.
For extreme performance, a higher battery voltage is very desirable.
The higher voltage will only take it so far and then the power will drop. its not cut and dried....
https://nrsyed.com/2018/01/21/how-to-read-a-dc-mot...
What were you thinking?
You've linked to 24V DC motors of a few hundred watts.....
The larger battery will have the lower internal resistance ? Nope not always, some of the smaller batteries have a lot lower resistances. And a series parallel combo ? could muster a significant output. Plus your battery chemistry, just how its constructed influences the way it can discharge.Also internal resistance doesnt stay static... So your simplistic view regarding sizes of batteries.. Hmmmmm.....
Here are the battery ratings for the global EV market in 2023, over 300 different models to choose from.....
Sure, there are some outliers, particularly the stupidly powerful hypercars and the stupidly large battery stuff.
Also some oddballs where smaller batteries have been shoehorned into ICE platforms.
Generally though, you aren't going get a powerful EV without at least 50 kWh under the bonnet and for really big power, 70 kWh is a minimum.
As I said in response to your comment about power, Ill stand with all that I ve said about power... kW and kWh are two completely different things.
You also know that a 70kWh battery wont actually give you 70kW for an hour dont you. and what was the picture off how did that fit in to what you said earlier, its like something completely different.
a 70kWh battery size is using the kWh as a means to yard stick the capacity of the battery. its more likely that the battery would be happier providing 7 kw for 10 hours or 3.5 kw for 20 hours.... Ive seen the internals of some batteries that have experienced someone trying to pull the figure quoted. In fact you may even find the internal construction of the battery not even rated to supply 70kW ! likewise you may find some types of batteries that are rated at 70kWh and can comfortably supply magnitudes of 70kW for short durations.
The whole kWh rating is very misleading.
Understanding the application and type of battery is one way to being able to process just how batteries are being used.
ruggedscotty said:
why is it sooooo hard to understand the kWh sizes ?
As I said in response to your comment about power, Ill stand with all that I ve said about power... kW and kWh are two completely different things.
You also know that a 70kWh battery wont actually give you 70kW for an hour dont you. and what was the picture off how did that fit in to what you said earlier, its like something completely different.
a 70kWh battery size is using the kWh as a means to yard stick the capacity of the battery. its more likely that the battery would be happier providing 7 kw for 10 hours or 3.5 kw for 20 hours.... Ive seen the internals of some batteries that have experienced someone trying to pull the figure quoted. In fact you may even find the internal construction of the battery not even rated to supply 70kW ! likewise you may find some types of batteries that are rated at 70kWh and can comfortably supply magnitudes of 70kW for short durations.
The whole kWh rating is very misleading.
Understanding the application and type of battery is one way to being able to process just how batteries are being used.
I was responding to a post where the poster was stating that reducing the battery mass will help improve the performance. As I said in response to your comment about power, Ill stand with all that I ve said about power... kW and kWh are two completely different things.
You also know that a 70kWh battery wont actually give you 70kW for an hour dont you. and what was the picture off how did that fit in to what you said earlier, its like something completely different.
a 70kWh battery size is using the kWh as a means to yard stick the capacity of the battery. its more likely that the battery would be happier providing 7 kw for 10 hours or 3.5 kw for 20 hours.... Ive seen the internals of some batteries that have experienced someone trying to pull the figure quoted. In fact you may even find the internal construction of the battery not even rated to supply 70kW ! likewise you may find some types of batteries that are rated at 70kWh and can comfortably supply magnitudes of 70kW for short durations.
The whole kWh rating is very misleading.
Understanding the application and type of battery is one way to being able to process just how batteries are being used.
My response was that, in general, the battery size does not inversely affect the performance on offer.
I've then posted a graph to show how the power rating of all EVs that are on sale today generally rises with battery size on offer.
The performance is defined by the power available for adding kinetic energy during bursts of acceleration.
Even if you remove the entire mass of the battery, you will still need most of that power for short duration to accelerate the car.
The rule of thumb for accelerating a car is 4.5 kW per ton per G per mph starting speed.
For perspective, 1G of acceleration is approximately 22 mph increase in speed per second.
A 2 ton car trying to accelerate at 0.5G from 50 mph will therefore require 225 kW at the driven wheels, plus whatever additional power is required to overcome drag, rolling resistance and cooling/heating loads in the car.
Looking at the chart shows that the cluster of 225 kW+ cars are around a 75 KWh or higher nominal battery size.
Yet those same cars won't need more than 30 kW to cruise at 70 mph.
The size of the battery is defined by the desired range, the car's frontal area and aerodynamic efficiency, and to a lesser degree, by the kerb mass.
Essentially, it is sized on order to provide sufficient energy to travel a certain distance at a certain speed.
Constant speed travel (at normal UK road speeds) is relatively low in terms of its power consumption but high in terms of energy consumption.
Conversely, a brisk acceleration event is relatively low in terms of energy consumption but requires high amounts of power for very short periods.
There is no real market (yet) for low-range, high-performance EVs, so there is no need for small batteries that can deliver high power.
What I think you are saying is that any size battery can be made to deliver any amount of power.
Of what practical benefit is that to a pure EV?
Should we also discuss what compromises that might entail regarding other aspects of the battery?
Small batteries can deliver big power for short periods.
Look at starter batteries for IC vehicles, one for my bike is 16Ah or 192Wh, and it can do 180A starter current for a few seconds.
That's the lead-acid version. The Lithium ones have similar current out of less than half the Ah.
So that's around 1.6kW (because it rips the volts down!) out of say 100Wh.
But that kind of power/capacity relationship is poor for both efficiency and cycle life.
I think what we have in many BEVs is higher performance than is really necessary, because once you've decided on a range, hence the battery capacity, the kind of performance you get from a Tesla doesn't add much cost. A 200kW motor doesn't cost much more than a 100kW item. And it doesn't kill the batteries in too few cycles, or require spending vastly more on other parts.
If you want significantly more power from the same batteries, it starts to seriously impact battery life and there's a lot less market for it.
You can buy electric bicycle kits with more aggressive power/capacity ratios, but nobody cares if they get a reputation for short life.
You can buy electric tools which take a lot of power out of a small battery, but nobody wants to run such things continuously.
Look at starter batteries for IC vehicles, one for my bike is 16Ah or 192Wh, and it can do 180A starter current for a few seconds.
That's the lead-acid version. The Lithium ones have similar current out of less than half the Ah.
So that's around 1.6kW (because it rips the volts down!) out of say 100Wh.
But that kind of power/capacity relationship is poor for both efficiency and cycle life.
I think what we have in many BEVs is higher performance than is really necessary, because once you've decided on a range, hence the battery capacity, the kind of performance you get from a Tesla doesn't add much cost. A 200kW motor doesn't cost much more than a 100kW item. And it doesn't kill the batteries in too few cycles, or require spending vastly more on other parts.
If you want significantly more power from the same batteries, it starts to seriously impact battery life and there's a lot less market for it.
You can buy electric bicycle kits with more aggressive power/capacity ratios, but nobody cares if they get a reputation for short life.
You can buy electric tools which take a lot of power out of a small battery, but nobody wants to run such things continuously.
EV have energy tailored cells rather than power than a PHEV or Hybrid where the battery is much smaller. The energy dense rather than power aren not as capable of high discharge…and yet they still have an excess of power really when it comes to peak discharge for the motors and some impressive 3C rates for continuous charge.
Edited by JonnyVTEC on Wednesday 15th March 21:39
What I think you are saying is that any size battery can be made to deliver any amount of power.
Of what practical benefit is that to a pure EV?
It is a huge benefit in terms of drive ability. obtain a level of performance and range. Some wont need a huge battery but wont want to trade off on performance.
Of what practical benefit is that to a pure EV?
It is a huge benefit in terms of drive ability. obtain a level of performance and range. Some wont need a huge battery but wont want to trade off on performance.
ruggedscotty said:
It is a huge benefit in terms of drive ability. obtain a level of performance and range. Some wont need a huge battery but wont want to trade off on performance.
The number of people who have told me that their EV has 'too much range' currently stands at zero. Maybe your experience is different.
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