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Old 23rd November 2020, 00:58   #526
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Default Re: The Electric Vehicle (EV) Landscape - A Deep Dive

Another hit piece by Forbes, sponsored by _ _ _.

Normal readers after reading Forbes article: The big boyz have come, now start the watch for demise of Tesla.

If the author would have really analysed what happened, why there is a sudden change of users behaviour, from selling several hundreds of cars in a country to less than hundred cars he would have got the answer. Did Tesla sell only because there is no competition all these years? Did all the "fanboys" bought their Tesla's already and no one left to purchase?

The truth is Tesla started selling their cars only in the continents they are made at. The Chinese market get their cars from Shanghai factory, North America gets from Fremont. Europe will get a significant number of cars from their Berlin factory once it's ready.

Until the Berlin factory is ready, Tesla is sending a ship or two to Europe to keep the presence. Just recently they have allotted 7000 cars (which are on their way) from their Shanghai factory( which had increased its capacity significantly) to Europe.

Forbes article in December: "Tesla shipped 7000 unsold cars to Europe from their Shanghai plant".
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Old 23rd November 2020, 19:41   #527
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Default Re: The Electric Vehicle (EV) Landscape - A Deep Dive

Couldn't find a mention of Simple Energy's new upcoming scooter on searching the forum ! Its supposed to provide twice the range of current EV scooters.

https://www.overdrive.in/news-cars-a...rst-e-scooter/
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Old 2nd December 2020, 19:18   #528
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UK says no more fossil fuel cars after 2030! As for Tesla it is the most valuable car company. Has overtaken GM and the lot.

Take it from me GM and co will go the way of Kodak- into oblivion. Kodak sold over 85% of the Photopaper. Now it is Zero. Olympus has moved out of the camera world.

Remember service may not be the money spinner it is now. EVs will have far fewer moving parts, and service may not be required. If a motor malfunctions it will be replaced.
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Old 22nd February 2021, 10:10   #529
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I think our country is now at the cusp of huge business opportunity in EV space. Not as much driven by environmental issues but due to Govt policies of taxing fuel exorbitantly. Growing economy needs travel and movement and it's not possible at the current level of fuel prices, EV remains the only alternative, public transport is just not going to match up in our country for another half a century.

The opportunity is more into people's EV than Tesla variety. I do see substantial EV ownership by 2022 as second gen EVs roll out this year.
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Old 9th April 2021, 17:32   #530
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Default Re: The Electric Vehicle (EV) Landscape - A Deep Dive

Energy Fractions in EVs

Some afternoon ramblings....

It is very encouraging to see Mercedes, VW, BMW, JLR, Volvo, MG all displaying real seriousness about EVs and the new range they are introducing or soon will be. The EV sweep might overtake us sooner than later - my guess. What we think will happen in 20 years might happen in 10 or 12.

Observations I have about the first generation of EVs are two - one they are continuing with the body construction norms & materials of ICE cars and two as a consequence these first generation EVs are way too heavy for the range the customer desires. Permit me to explain.

EVs are like aircraft - you operate on the margin of energy you can carry or generate respectively with respect to the performance the machine is expected to deliver. This is unlike ICE cars that may spend their lives at an average of 50 kmph but can clock 3X that speed easily. In aircraft that might be speed & lift and in EVs it translates to range. In aviation we have a concept called fuel fraction i.e. {weight of fuel}/{all up weight}. Simply put it tells you what range an aircraft can fly economically after which if you try to carry more fuel (in order to increase range} you need fuel to carry that fuel and extra structural weight to carry the fuel that carries the fuel that gives the extra range!!

Given that energy density of batteries is way below that of petroleum a similar concept, directionally speaking, would apply to EV cars -let's term it energy fraction. I am sure the designers of EVs are conscious of this concept - if I am they certainly must be. But when I look at the net empty weight of these cars, even after deducting some reasonable number for their batteries, they are heavy. The materials and structural design technology used in the chassis/hull of the car needs to get to a point where battery weight is roughly 33%* of the all up weight of the car, including payload, to start delivering really meaningful real world ranges of say 500 to 600 kms. That is probably a WLTP range of 750 to 850 kms.

The Tesla S has a battery weight of 540 kgs versus an all up weight of 2250 kgs. That's a ratio of 25%. I suspect Tata Nexon etc are lower. Don't know the number for the new models Mercedes and VW are introducing. Of course improvements in battery energy density will change things but the concept of fuel fraction will still hold. Right now because we are building cars largely of steel and aluminium we have not tested the limits of economical fuel fractions with batteries.

* Just my thumb rule guesstimate
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Old 9th April 2021, 23:12   #531
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Quote:
Originally Posted by V.Narayan View Post
Energy Fractions in EVs

Some afternoon ramblings....

It is very encouraging to see Mercedes, VW, BMW, JLR, Volvo, MG all displaying real seriousness about EVs and the new range they are introducing or soon will be. The EV sweep might overtake us sooner than later - my guess. What we think will happen in 20 years might happen in 10 or 12.
..
The Tesla S has a battery weight of 540 kgs versus an all up weight of 2250 kgs. That's a ratio of 25%. I suspect Tata Nexon etc are lower.]
Nexon EV Battery pack is 260KG and Vehicle weight is 1400KG. So thats 18.5%.
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Old 10th April 2021, 00:53   #532
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Quote:
Originally Posted by V.Narayan View Post
Energy Fractions in EVs
....

i.e. {weight of fuel}/{all up weight}. Simply put it tells you what range an aircraft can fly economically after which if you try to carry more fuel (in order to increase range} you need fuel to carry that fuel and extra structural weight to carry the fuel that carries the fuel that gives the extra range!!
Interesting to compare the EV battery vs kerb weights. Adding to the list :

BMW i3 120Ah (42.2kWh gross / 38kWh net) - 265kg pack / 1345kg kerb - 19.7%
Tesla model 3 LR AWD (80kWh gross / 75 kWh usable) - 480kg pack / 1847kg kerb - 25.9%

It would be also useful to have the kerb weight/Range ratios, as this will give a good indication of which EV is more efficient. For normalising, I used WLTP ranges:

i3 120Ah - 1345kg / 308km - 4.36kg/km
model 3 LR AWD - 1847kg / 580km - 3.18kg/km

Lower the better in both cases.

Last edited by carthick1000 : 10th April 2021 at 00:55.
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Old 10th April 2021, 08:34   #533
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Default Re: The Electric Vehicle (EV) Landscape - A Deep Dive

Quote:
Originally Posted by carthick1000 View Post
Interesting to compare the EV battery vs kerb weights. Adding to the list :

BMW i3 120Ah (42.2kWh gross / 38kWh net) - 265kg pack / 1345kg kerb - 19.7%
Tesla model 3 LR AWD (80kWh gross / 75 kWh usable) - 480kg pack / 1847kg kerb - 25.9%

It would be also useful to have the kerb weight/Range ratios, as this will give a good indication of which EV is more efficient. For normalising, I used WLTP ranges:

i3 120Ah - 1345kg / 308km - 4.36kg/km
model 3 LR AWD - 1847kg / 580km - 3.18kg/km

Lower the better in both cases.
That's neat. So let me add to my earlier post #530. I'll stay with my comparisons to aircraft design because in both EVs and aircraft literally every kilo of weight counts. In aircraft while determining lift and associated safety margins and in EVs while determining range and its safety margins.

In aircraft design we look at maximum weight without fuel i.e. the empty weight plus payload. Aircraft ranges have improved as much due to better engines {turbojets --> turbofans --> high bypass ratio turbofans etc} as it has due to making the structure lighter and stronger. Every kilo saved on structure means there is one kilo less of non-battery, non-payload weight to pull and it creates space for one kilo of extra battery capacity i.e. it adds value to both ends of the range equation.

Car makers will need to start looking at every ounce of weight under a magnifying glass. Once an airline wanted little video screens installed at the back of each seat. Now a common thing but back then a novelty. We were given the job. 185 seats x 450 grammes per video screen = 83 kilos. Even that 83 kilos had to be weighed in on costing of its impact on fuel cost per hour of flying. 83 kilos on an aircraft with an all up weight of around 93,500 kilos. That is how maniacal the car designers need to get about weight.
Quote:
Originally Posted by Holyghost View Post
Nexon EV Battery pack is 260KG and Vehicle weight is 1400KG. So thats 18.5%.
Thank you @HolyGhost

Last edited by V.Narayan : 10th April 2021 at 08:37.
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