[ajayc123]

Here's the point. By the time data gets generated for a specific technology (say 15 years), the technology is likely going to be obsolete, and be replaced by a newer technology which may take another decade to prove itself.

So, we need to take the leap of faith based on available information and be prepared for a bit of risk. Leave the analysis paralysis and move forward (either way).

In any product life cycle there will be early adopters and late adopters. My personal conclusion is that I am ready for the leap, and there will always be people on both sides. How about you?

[carmayogi]

Originally Posted by EV NXT

That is exactly my question to you too. When there is no data of BEV’s in the world that have lasted more than 8 years how do you project a life of 10 years or more? Isn't that guess work too?

And we haven’t even got to the cost of drive train and motor repairs which may also be just a replacement given that there will not be too many that will know how to repair them. This would be a prohibitively expensive too.

Been reading a lot of your posts and there is a lot of incorrect information in there. The early EVs, especially the Nissan Leaf, did suffer from poor battery longevity.

The current (known) holder of long distance driving in a Tesla Model S has clocked over 1.6 MILLION km with repair costs of approx 13k Euros over that period including 2 battery packs and a few other things. I cannot think of a petrol or diesel car that could do the same.

There are several examples of EVs with over 100k or 200k or 300k km on their odometers with minimal maintenance.

There will surely be some stories of people who suffer from issues earlier, but that is true of any mass produced fossil car with engine/transmission issues earlier than expected. Warranty helps in many of these situation.

Most EVs have warranties of 8-10 yrs on the battery with >150k km limits. Furthermore, it is false information to say an EV cannot be used if the battery drops below 70% of its original capacity.

Personally I've had laptops & phones that died pretty quickly with battery issues - this is increasingly rare these days. Battery tech has come a long way. With more & more batteries on the road, data & experience will lead to further improvements.

[carmayogi]

Originally Posted by soarersc300

That is very much true. The energy density on NMC is more than one and a half times that of LFP. However in the real world when you take long journeys you will end up with a charging pit stop when your NMC battery drains to 20% and will charge till 80% and proceed. For LFP you can go down till almost 0% and charge all the way up till 100%. That's why I had mentioned for all practical purposes 300 km range in LFP is practically same as 500 km range in NMC.

This is not exactly accurate. The point of an NMC chemistry is that you can go close to 0% and fast charge to nearly full without damaging the battery very much at all. The key is to not park the car with too low or too high a charge. This is why when you have an NMC Tesla, the charging settings screen have maximum limits named as Daily (60-80%) and Trip (80-100%). If you start with 100%, go down to 5%, charge to 90% etc all on a single trip in a single day, it's fine.

The point of NMC is to use it as a ~300km range car in daily use but a ~500km car a handful of times a year when you actually do longer trips. On your road trip days, use the full pack. On others, use 60% of the pack.

That said, LFP energy density continues to improve and at some point, it may be more than enough for most EV drivers to use. It's already close with the standard range Tesla 3 doing ~400km vs ~550km on the NMC long range.

[ajayc123]

Originally Posted by carmayogi

This is not exactly accurate. The point of an NMC chemistry is that you can go close to 0% and fast charge to nearly full without damaging the battery very much at all. The key is to not park the car with too low or too high a charge. This is why when you have an NMC Tesla, the charging settings screen have maximum limits named as Daily (60-80%) and Trip (80-100%). If you start with 100%, go down to 5%, charge to 90% etc all on a single trip in a single day, it's fine.

The point of NMC is to use it as a ~300km range car in daily use but a ~500km car a handful of times a year when you actually do longer trips. On your road trip days, use the full pack. On others, use 60% of the pack.

What is your assessment on NMC vs LFP on the following aspects?
1. recharge cycles,
2. age related deterioration (say beyond 8-10 years)
3. Stability vs sudden drop in SoC while driving/ parked
4. Retention/loss of charge if parked over a few days

[flanker]

Originally Posted by EV NXT

I thought i’d call it quits but it looks like we are getting a lot of misleading information.

Here is the exact opposite to the quoted bit on the Mk1 Leaf:

The information you are providing is in-itself misleading. Leaf used to have an air cooled battery, which is terrible for thermal management. High battery temperatures cause much faster aging and failures.

All EVs currently in India are liquid cooled. This case of Leaf is not even applicable.

[outdoorlover]

With range being all the rage in EVs, there’s a lot of work happening on squeezing out the last km out of the batteries while batteries themselves evolve to deliver more. One of the things that would be key here is to make the vehicle lighter which would impact the build to some extent. The other thing that could contribute to a lower weight is the motor weight itself which can be bright down by increasing the speed at which they spin. Here’s some new work that’s happening in that direction:

https://interestingengineering.com/i...ock-100000-rpm

[carmayogi]

Originally Posted by ajayc123

What is your assessment on NMC vs LFP on the following aspects?
1. recharge cycles,
2. age related deterioration (say beyond 8-10 years)
3. Stability vs sudden drop in SoC while driving/ parked
4. Retention/loss of charge if parked over a few days

It is true that any non LFP chemistry has to be "babied" a bit more, meaning one has to pay more attention. With software, this is not too difficult. As I mentioned in an earlier thread, there are so called daily driving charge limits that can be set easily.

For degradation, there's not enough data from LFP cars on how they will fare after 8-10 yrs. Well maintained NMC or NCA chemistries still have 70-90% of their original life after several years. Of course, this is based on info from owners and some aggregated data through various EV tracking apps.

A modern battery should not show any sudden drops in range, unless parked in extreme cold. A cold soaked battery will regain some charge when warmed up.

From what I know, range loss while parked is more to do with the phantom drain of the car's electronics than the battery chemistry. Again, in extreme cold or heat, the thermal management systems might kick in more often. Phantom drain means things like having the vehicle connected to the internet, running systems like Tesla's Sentry Mode or some inefficient software that runs in the background like on my Macbook that recently refused to sleep without losing significant battery - fortunately sorted in the latest iOS update.

[flanker]

Originally Posted by carmayogi

A modern battery should not show any sudden drops in range,

With LFP batteries this does happen. As the battery voltage and state of charge are not clearly correlated, the BMS has to frequently re-calibrate to judge the SoC. This happens with Nexon EV and the ZS EV 2022, both being LFP. Tesla LFP also reported the same issues.

The way to fix or avoid this is to discharge to a very low SoC and then charge to 100% to re-calibrate the BMS.

[SanSabh]

Originally Posted by outdoorlover

With range being all the rage in EVs, there’s a lot of work happening on squeezing out the last km out of the batteries while batteries themselves evolve to deliver more. One of the things that would be key here is to make the vehicle lighter which would impact the build to some extent. The other thing that could contribute to a lower weight is the motor weight itself which can be bright down by increasing the speed at which they spin. Here’s some new work that’s happening in that direction:

https://interestingengineering.com/i...ock-100000-rpm

Thanks
Very interesting article! Going down a rabbit hole in a good way

[ng565]

So what would be the final take on BYD E6 Blade Battery where they offer 5,00,000 km warranty over a period of 8 years. I have only used 75,000 km on my Hyundai i10 in 15 years but would like to see that figure cross at least the 1,00,000 km mark on BYD E6.

[niranjanprabhu]

I will also add SoH or State of Health of a battery. We all know this as the percentage of life left in our phones batteries. Similarly in EVs as well. Tesla cars manufactured in 2013 and having run over 150k miles still retain SoH of over 90%. The moment the SoH dips below 80% it's called as Second Life of the battery and it needs to be changed. It's good for use in home UPS but not in EVs

The other important acronym is DoD or Depth of Discharge. Usually for good battery health it's important NOT to charge till 100% SoC (State of Charge) and NEVER deplete it to 0% either. If the EV owner decides to maintain charge between 10% and 90% for example the DoD is said to be 80%

[whitewing]

It is imperative that more sustainable means of transportation for the sake of the next generation.

Originally Posted by carmayogi

.....
.....
Energy use
The reason EVs are being championed so hard is their energy efficiency. Between the power plant, transmission, charging & use of energy, the round trip efficiency is between 75-90%. ...
...
EV is approx 9-12 liters of fuel. 9-12 liters can take you 500-700 km. Mind blowing! This is also the reason why an EV running off coal or natural gas power is still significantly cleaner than a fossil car....

In the context of India I need to point out, currently, EVs are either probably on par or slightly worse off than their gas powered compatriots.


I base the statement out of the following report https://www.reuters.com/business/aut...rs-2021-06-29/

Reuters analysis of data from a model that calculates the lifetime emissions of vehicles
...
..
The model was developed by the Argonne National Laboratory in Chicago and includes thousands of parameters from the type metals in an electric vehicle (EV) battery to the amount of aluminium or plastic in a car.
Argonne's Greenhouse Gases, Regulated Emissions and Energy Use in Technologies (GREET) model is now being used with other tools to help shape policy at the U.S. Environmental Protection Agency (EPA) and the California Air Resources Board, the two main regulators of vehicle emissions in the United States.
..
..
But estimates as to how big that carbon gap is when a car is first sold and where the "break-even" point comes for EVs during their lifetime can vary widely, depending on the assumptions.
Kelly said the payback period then depends on factors such as the size of the EV's battery, the fuel economy of a gasoline car and how the power used to charge an EV is generated.
Reuters plugged a series of variables into the Argonne model, which had more than 43,000 users as of 2021, to come up with some answers.

The Tesla 3 scenario above was for driving in the United States, where 23% of electricity comes from coal-fired plants, with a 54 kilowatt-hour (kWh) battery and a cathode made of nickel, cobalt and aluminum, among other variables.

It was up against a gasoline-fueled Toyota Corolla weighing 2,955 pounds with a fuel efficiency of 33 miles per gallon. It was assumed both vehicles would travel 173,151 miles during their lifetimes.

But if the same Tesla was being driven in Norway, which generates almost all its electricity from renewable hydropower, the break-even point would come after just 8,400 miles.

If the electricity to recharge the EV comes entirely from coal, which generates the majority of the power in countries such as China and Poland, you would have to drive 78,700 miles to reach carbon parity with the Corolla, according to the Reuters analysis of data generated by Argonne's model.

Now, given that India will probably be at around ~70% thermal for some years to come. And the grid encounters T&D losses of around 20%(not sure if pilferage is also part of this numbers).

This implies that the break even happens for an EV only if it runs for around 1Lakh km.

[flanker]

Originally Posted by whitewing

I base the statement out of the following report https://www.reuters.com/business/aut...rs-2021-06-29/
Now, given that India will probably be at around ~70% thermal for some years to come. And the grid encounters T&D losses of around 20%(not sure if pilferage is also part of this numbers).

This implies that the break even happens for an EV only if it runs for around 1Lakh km.

The model used for these calculations doesn't account for second-life use or even recycling of the batteries. The EV cars being bought now in India will last for next 10 to 15 years and there is significant chance that these batteries will be reused or recycled.

It is a very big assumption to say that the mix will remain 70% coal for next 10 to 15 years. Even so, high percentage of these EVs will reach even the 1L car.

Beyond just the carbon footprint and global warming, we have also the question of particulate matter emissions, sulphur and nitrous oxides. Cars also have a significant percentage contribution to this in context of cities. Most of our cities are at 10 to 100 times the WHO safe limit of particulate pollution.

[aim120]

Originally Posted by niranjanprabhu

I The moment the SoH dips below 80% it's called as Second Life of the battery and it needs to be changed. It's good for use in home UPS but not in EVs

Again please refer this post (All the basics about Electric Cars),

[whitewing]

Originally Posted by flanker

The model used for these calculations doesn't account for second-life use or even recycling of the batteries. The EV cars being bought now in India will last for next 10 to 15 years and there is significant chance that these batteries will be reused or recycled.

Understood. And let us hope these projections turn out to be true for own collective good.

Coming to the present. I've tried looking around for info, but very little available (even in terms of projection) apart from the study I shared above and this paper in Nature (this a contributor from IITK and researchers from Aramco).
The researchers have compared petrol, diesel and electric versions of Tigor, Nexon and Verito (paper was submitted in 2021).

The paper in nature provides a comparison of the region and the impact on the emissions.
And essentially concludes that if a EV is charged in
- the NE/North/South india, there is a reduction in the emissions.
- the western and eastern parts of India (due to the grid being supplied via thermal power), this is currently actually increasing the emissions !!

Originally Posted by flanker

It is a very big assumption to say that the mix will remain 70% coal for next 10 to 15 years. Even so, high percentage of these EVs will reach even the 1L car.

India aims to achieve 50% coal by 2030. So, safe to say that fossil fuel % will be significantly lower than what it is now may be around ~60% given that there will be slippages.
The lifecycle apparently includes the recycling credits (see Supplementary Figure 6 in the article).

If one looks at the following rate of growth over the past decades, one can't be too optimistic.