Mercedes Says Synthetic Fuel Isn’t Viable For The Auto Industry

[ABN_CBT_ENGR]

Originally Posted by y_p_w



Exactly where did I refer to any vehicle tests? The discussion was about how high speed charging affects battery capacity. You're changing the subject again.

Real world results are that the models for battery degradation are pretty reliable. Tesla expects that a Model 3 battery should last at least 300,000 miles before it's maybe down to 80% of the original capacity. I've heard of some owners that have set their max charge to 80% and expect that the battery will last a million miles. And if it fails it can be replaced under warranty or for maybe $5000. I certainly get that there are random failures, but that can happen with any technology. I've had a rear idler gear break necessitating an expensive transmission rebuild. Sometimes engines fail for random reasons. I expect with any vehicle there will be premature failures as well as. I fully expect that the drivetrain will be the most reliable part of an electric car, but the battery might actually fail. But real world results (at least with Tesla that liquid cools their batteries) seem to be that their batteries are pretty reliable.


Those "tests" were on this subject. You need an education and stop taking doubletalk as gospel.

First- batteries don't last "miles" they last charging cycles. ( that's media hype)

Those charging cycles are based on battery usable capacity versus the maximum load ( the part they don't want you knowing the details of- otherwise they wouldn't camouflage it with all the colorful words and abstract references always in some future tense)

Wait till the price of the battery and its dimension comes out ( measured against its life estimate)- to build what they want is possible but it will have to have its own vehicle to tow it while its powering the car.

Cant get a negotiated plea on the laws of physics

You peddle hyperbole you don't understand using comparisons that are non sequitur.

Not the best way to prove a point- yet another fail

 

[BMWTurboDzl]

Originally Posted by Cujet
And yet we use Ethanol in large quantities. It may not qualify as a synthetic, but it certainly qualifies as way to transform "green energy" (sunlight) into liquid fuel. A liquid that pours into the tank in a minute or two, and delivers adequate overall performance, without the limitations of batteries.

Before we argue over ethanol's EROI, remember that methods exist to achieve an EROI of 6+ with ethanol. Brazil does it.

I really hope to see 800wh/kg specific energy in next decade's batteries, 3X+ better than today's best. Tomorrow, even Musk's best 200KWH battery Tesla pickup truck can't tow a conventional RV trailer for more than 100 miles. The truck also takes an hour or more to charge, and may not be chargeable at remote destinations.

Mercedes and VW may believe that filling a battery with sunshine is the best choice. I don't agree. It takes real power to do real work. There is a distinct reason why electric airplanes don't exist, despite 2 decades of attempts.


Brazil does it with cane which apparently is easy to grow in their tropical climate (Two growing seasons in Brazil). That's a little different vs the temperate US where corn is only grown once a year and requires comparatively more fertilizer.

 

[y_p_w]

Originally Posted by ABN_CBT_ENGR
Originally Posted by y_p_w



Exactly where did I refer to any vehicle tests? The discussion was about how high speed charging affects battery capacity. You're changing the subject again.

Real world results are that the models for battery degradation are pretty reliable. Tesla expects that a Model 3 battery should last at least 300,000 miles before it's maybe down to 80% of the original capacity. I've heard of some owners that have set their max charge to 80% and expect that the battery will last a million miles. And if it fails it can be replaced under warranty or for maybe $5000. I certainly get that there are random failures, but that can happen with any technology. I've had a rear idler gear break necessitating an expensive transmission rebuild. Sometimes engines fail for random reasons. I expect with any vehicle there will be premature failures as well as. I fully expect that the drivetrain will be the most reliable part of an electric car, but the battery might actually fail. But real world results (at least with Tesla that liquid cools their batteries) seem to be that their batteries are pretty reliable.


Those "tests" were on this subject. You need an education and stop taking doubletalk as gospel.

First- batteries don't last "miles" they last charging cycles. ( that's media hype)

Those charging cycles are based on battery usable capacity versus the maximum load ( the part they don't want you knowing the details of- otherwise they wouldn't camouflage it with all the colorful words and abstract references always in some future tense)

Wait till the price of the battery and its dimension comes out ( measured against its life estimate)- to build what they want is possible but it will have to have its own vehicle to tow it while its powering the car.

Cant get a negotiated plea on the laws of physics

You peddle hyperbole you don't understand using comparisons that are non sequitur.

Not the best way to prove a point- yet another fail

I've been trying to stay away from this because all I see from you are insults, handwaving, and declarations of victory.

You can claim about miles vs charging cycles being different things, but they're pretty much proportional. There's also the matter of avoiding the extreme ranges of charge in order to increase longevity. They're already doing that to some degree, where 0% and 100% are chosen. It's well known that two 75% to 25% cycles is better for a battery than a single 100% to 0% cycle.

You mention physics, but this is more a matter of engineering. And the engineering has been pretty darn good. Engineering is about coming up with solutions, making tradeoffs, and not complaining about limitations.

In the real world we've got over a decade of experience from Tesla, and batteries have maintained capacity and performance exceptionally well. If all an owner does is short trips, they can be programmed for a maximum charge range. There's one owner who capped the max charge at 80% and estimates he should won't need to replace the battery for 20 years with his typical use.

I'm still trying to understand your jihad against electric vehicles.

 

[y_p_w]

Originally Posted by BMWTurboDzl
Originally Posted by Cujet
And yet we use Ethanol in large quantities. It may not qualify as a synthetic, but it certainly qualifies as way to transform "green energy" (sunlight) into liquid fuel. A liquid that pours into the tank in a minute or two, and delivers adequate overall performance, without the limitations of batteries.

Before we argue over ethanol's EROI, remember that methods exist to achieve an EROI of 6+ with ethanol. Brazil does it.

I really hope to see 800wh/kg specific energy in next decade's batteries, 3X+ better than today's best. Tomorrow, even Musk's best 200KWH battery Tesla pickup truck can't tow a conventional RV trailer for more than 100 miles. The truck also takes an hour or more to charge, and may not be chargeable at remote destinations.

Mercedes and VW may believe that filling a battery with sunshine is the best choice. I don't agree. It takes real power to do real work. There is a distinct reason why electric airplanes don't exist, despite 2 decades of attempts.


Brazil does it with cane which apparently is easy to grow in their tropical climate (Two growing seasons in Brazil). That's a little different vs the temperate US where corn is only grown once a year and requires comparatively more fertilizer.

Even in tropical parts of the US (Louisiana and Florida) where sugar cane is grown commercially, it doesn't grow like it does in Brazil. It does grow really well in Hawaii, but for various reasons (the cost of labor and cheaper growing in other countries) there's no commercial crop there any more.

I found this article about growing sugarcane in Alabama as a fuel crop. Apparently the company that my relative worked for wanted to set up a small demonstration plant.

Quote
https://www.farmprogress.com/sugarcane-alabamas-future
The growing demand for biofuel, especially a U.S. Air Force plan to begin powering its jet fleets with plant-based alternatives to conventional jet fuel by 2011, may open new opportunities for growing the crop in Alabama.

That, in turn, has sparked the interest of a California-based biotechnology company, Amyris, which has worked with the Alabama Cooperative Extension System to develop a 100-acre sugarcane demonstration field. If the demonstration proves successful, Amyris hopes to build a processing plant in southern Alabama to help meet the growing demand for biofuels.

 

[ABN_CBT_ENGR]

Originally Posted by y_p_w



I've been trying to stay away from this because all I see from you are insults, handwaving, and declarations of victory.

You can claim about miles vs charging cycles being different things, but they're pretty much proportional. There's also the matter of avoiding the extreme ranges of charge in order to increase longevity. They're already doing that to some degree, where 0% and 100% are chosen. It's well known that two 75% to 25% cycles is better for a battery than a single 100% to 0% cycle.

You mention physics, but this is more a matter of engineering. And the engineering has been pretty darn good. Engineering is about coming up with solutions, making tradeoffs, and not complaining about limitations.

In the real world we've got over a decade of experience from Tesla, and batteries have maintained capacity and performance exceptionally well. If all an owner does is short trips, they can be programmed for a maximum charge range. There's one owner who capped the max charge at 80% and estimates he should won't need to replace the battery for 20 years with his typical use.

I'm still trying to understand your jihad against electric vehicles.


oh puhleeze, stop with the ad hom whining because I have made no insults, no handwaving or declarations. I have given you hard facts, actual data, real world physics from a qualified individual by degree and professional license- you just cant address them directly so you try to flank and I check your argument just like I am about to do once again. You don't like it because it throws reality into your worldview and hurts your feelings. Maybe you ought to "fact check" the strength and accuracy of your views first rather than parroting market developed hyperbole as legitimate science and engineering.

--You can claim about miles vs charging cycles being different things, but they're pretty much proportional.

There's no such thing as a battery charging cycle being "proportional" to miles on an odometer, such a thought is absurd beyond further comment. That's not a "claim" that's a FACT.

---There's also the matter of avoiding the extreme ranges of charge in order to increase longevity

What does that mean exactly? The only thing that matters is the battery's state of discharge relative to its mass and density as it applies to the charge rate as to how much and fast it will charge. Do you even understand what you just wrote?

---They're already doing that to some degree, where 0% and 100% are chosen.

Another information less vague ambiguity. Who is "they" and what "degree" have they done "something"?

--It's well known that two 75% to 25% cycles is better for a battery than a single 100% to 0% cycle.

Actually that depends on the battery, charge rate, actual state of discharge and a host of other considerations. Your oversimplification isn't a legitimate point to be considered

--You mention physics, but this is more a matter of engineering.

Ya think? I happen to do both and have actually designed batteries ( in a different century)- what is your skill level and experience in either?

--- Engineering is about coming up with solutions, making tradeoffs, and not complaining about limitations.

Never mind, you just answered my question above

---In the real world we've got over a decade of experience from Tesla, and batteries have maintained capacity and performance exceptionally well.

What is the name of this world you speak of and what actual performance standards did these batteries perform well against? (compared against fossil fuels in an ICE performance EQUALLY- don't forget that part)

---If all an owner does is short trips, they can be programmed for a maximum charge range. There's one owner who capped the max charge at 80% and estimates he should won't need to replace the battery for 20 years with his typical use.

Just curious- what legitimate test came up with this result? Pure hyperbole and marketing hype

---I'm still trying to understand your jihad against electric vehicles

I have none, I support the development of them and concur they have a legitimate market. Never said anything differently. However they have severe limitations, hidden costs and other constraints that are being deliberately hidden from the general public and they are severely misrepresented in terms of true cost and benefit for the end goal of eliminating the fossil fuel industry as a result of a green agenda.

There you have it, once again, facts and data. Another fail for the anecdotal marketing based pseudo-science

If you can develop and present actual scientific data, I would love to discuss it with you.

 

[y_p_w]

Originally Posted by ABN_CBT_ENGR
Originally Posted by y_p_w



I've been trying to stay away from this because all I see from you are insults, handwaving, and declarations of victory.

You can claim about miles vs charging cycles being different things, but they're pretty much proportional. There's also the matter of avoiding the extreme ranges of charge in order to increase longevity. They're already doing that to some degree, where 0% and 100% are chosen. It's well known that two 75% to 25% cycles is better for a battery than a single 100% to 0% cycle.

You mention physics, but this is more a matter of engineering. And the engineering has been pretty darn good. Engineering is about coming up with solutions, making tradeoffs, and not complaining about limitations.

In the real world we've got over a decade of experience from Tesla, and batteries have maintained capacity and performance exceptionally well. If all an owner does is short trips, they can be programmed for a maximum charge range. There's one owner who capped the max charge at 80% and estimates he should won't need to replace the battery for 20 years with his typical use.

I'm still trying to understand your jihad against electric vehicles.


oh puhleeze, stop with the ad hom whining because I have made no insults, no handwaving or declarations. I have given you hard facts, actual data, real world physics from a qualified individual by degree and professional license- you just cant address them directly so you try to flank and I check your argument just like I am about to do once again. You don't like it because it throws reality into your worldview and hurts your feelings. Maybe you ought to "fact check" the strength and accuracy of your views first rather than parroting market developed hyperbole as legitimate science and engineering.

--You can claim about miles vs charging cycles being different things, but they're pretty much proportional.

There's no such thing as a battery charging cycle being "proportional" to miles on an odometer, such a thought is absurd beyond further comment. That's not a "claim" that's a FACT.

---There's also the matter of avoiding the extreme ranges of charge in order to increase longevity

What does that mean exactly? The only thing that matters is the battery's state of discharge relative to its mass and density as it applies to the charge rate as to how much and fast it will charge. Do you even understand what you just wrote?

---They're already doing that to some degree, where 0% and 100% are chosen.

Another information less vague ambiguity. Who is "they" and what "degree" have they done "something"?

--It's well known that two 75% to 25% cycles is better for a battery than a single 100% to 0% cycle.

Actually that depends on the battery, charge rate, actual state of discharge and a host of other considerations. Your oversimplification isn't a legitimate point to be considered

--You mention physics, but this is more a matter of engineering.

Ya think? I happen to do both and have actually designed batteries ( in a different century)- what is your skill level and experience in either?

--- Engineering is about coming up with solutions, making tradeoffs, and not complaining about limitations.

Never mind, you just answered my question above

---In the real world we've got over a decade of experience from Tesla, and batteries have maintained capacity and performance exceptionally well.

What is the name of this world you speak of and what actual performance standards did these batteries perform well against? (compared against fossil fuels in an ICE performance EQUALLY- don't forget that part)

---If all an owner does is short trips, they can be programmed for a maximum charge range. There's one owner who capped the max charge at 80% and estimates he should won't need to replace the battery for 20 years with his typical use.

Just curious- what legitimate test came up with this result? Pure hyperbole and marketing hype

---I'm still trying to understand your jihad against electric vehicles

I have none, I support the development of them and concur they have a legitimate market. Never said anything differently. However they have severe limitations, hidden costs and other constraints that are being deliberately hidden from the general public and they are severely misrepresented in terms of true cost and benefit for the end goal of eliminating the fossil fuel industry as a result of a green agenda.

There you have it, once again, facts and data. Another fail for the anecdotal marketing based pseudo-science

If you can develop and present actual scientific data, I would love to discuss it with you.

The city and highway eMPG of most electrics are about the same. How many charge cycles correlates extremely closely with the mileage.

When you've got a car on its original battery with over 200,000 miles with 90% of its capacity remaining, I'd say that's a pretty good indicator that the batteries last. However, someone with a depleted battery but otherwise happy with the car might be willing to spend $5000 on a battery replacement on a car that cost $50,000 new.

It's extremely well understood that battery longevity can be increased by avoiding the extremes of the charge range. This is done all the time computers (my Lenovo laptop has a "maximum longevity" setting where I can use half the battery capacity, and EV car companies have settings to program the maximum charge level. The guy who estimates it will last 20 years is a battery researcher. Elon Musk specifically recommends keeping a battery within 30-80%. There are various rules of thumb including 20-80% or 40-80% in order to maximize battery longevity. The battery researcher actually recommended 70%, which one Telsa owner is doing on his advice.

Quote
https://electrek.co/2017/09/01/tesla-battery-expert-recommends-daily-battery-pack-charging/
Jeff Dahn, a renowned battery researcher and the leader of Tesla's research partnership through his battery-research group at Dalhousie University, has been working on li-ion battery durability for Tesla for a year now.

He has been studying the impact of the charge and discharge rates on the lifecycle of Tesla's batteries.

https://teslamotorsclub.com/tmc/thr...on-long-term-battery-preservation.97134/
I decided to do a video on this as it's a fairly common question I've come across and hard not to get several different answers. So, I reached out to Jeff Dahn (Tesla Industrial Research Chair and Professor of Physics and Atmospheric Science at the University of Dalhousie in Nova Scotia). I advised I was planning to keep my X for approximately 2 decades and asked him where he'd charge the battery to for day-to-day use, with long term preservation in mind.

For those that don't wish to watch the video he recommends daily charging to 70 percent and to go ahead and charge to 100 percent for longer trips. He also comments on Vancouver being a nice climate for lithium ion batteries. Cheers.


I have worked in engineering, and absolutely it's about coming up with solutions knowing the limitations of the technology. In my field the tradeoff is power, area, and cost.

 

[ABN_CBT_ENGR]

Originally Posted by y_p_w

The city and highway eMPG of most electrics are about the same. How many charge cycles correlates extremely closely with the mileage.

When you've got a car on its original battery with over 200,000 miles with 90% of its capacity remaining, I'd say that's a pretty good indicator that the batteries last. However, someone with a depleted battery but otherwise happy with the car might be willing to spend $5000 on a battery replacement on a car that cost $50,000 new.

It's extremely well understood that battery longevity can be increased by avoiding the extremes of the charge range. This is done all the time computers (my Lenovo laptop has a "maximum longevity" setting where I can use half the battery capacity, and EV car companies have settings to program the maximum charge level. The guy who estimates it will last 20 years is a battery researcher. Elon Musk specifically recommends keeping a battery within 30-80%. There are various rules of thumb including 20-80% or 40-80% in order to maximize battery longevity. The battery researcher actually recommended 70%, which one Telsa owner is doing on his advice.

Quote
https://electrek.co/2017/09/01/tesla-battery-expert-recommends-daily-battery-pack-charging/
Jeff Dahn, a renowned battery researcher and the leader of Tesla's research partnership through his battery-research group at Dalhousie University, has been working on li-ion battery durability for Tesla for a year now.

He has been studying the impact of the charge and discharge rates on the lifecycle of Tesla's batteries.

https://teslamotorsclub.com/tmc/thr...on-long-term-battery-preservation.97134/
I decided to do a video on this as it's a fairly common question I've come across and hard not to get several different answers. So, I reached out to Jeff Dahn (Tesla Industrial Research Chair and Professor of Physics and Atmospheric Science at the University of Dalhousie in Nova Scotia). I advised I was planning to keep my X for approximately 2 decades and asked him where he'd charge the battery to for day-to-day use, with long term preservation in mind.

For those that don't wish to watch the video he recommends daily charging to 70 percent and to go ahead and charge to 100 percent for longer trips. He also comments on Vancouver being a nice climate for lithium ion batteries. Cheers.


I have worked in engineering, and absolutely it's about coming up with solutions knowing the limitations of the technology. In my field the tradeoff is power, area, and cost.


Holy dead batteries Batman, the farce is strong with this one

Here we go again, another failed attempt to try to pass off hyperbole and marketing claims as a legitimate science

---The city and highway eMPG of most electrics are about the same. How many charge cycles correlates extremely closely with the mileage.

It's a meaningless metric capturing meaningless data in terms of actual battery properties because this alleged "empg" changes DRASTICALLY with the type of vehicle, payload, other loads and so forth. Charge cycles depends on lots of variables. Once again, junk data from a junk science marketing plan

---When you've got a car on its original battery with over 200,000 miles with 90% of its capacity remaining, I'd say that's a pretty good indicator that the batteries last.

As stated, depends on a lot of things previously defined, this is too simplistic to be of any real value without knowing what all of them were in order to scale and qualify those claims.

---However, someone with a depleted battery but otherwise happy with the car might be willing to spend $5000 on a battery replacement on a car that cost $50,000 new.

Someone once said "hope is not a strategy" and "might" is hardly a measurable scientific finding. Is "happy" a factor in battery testing?

What if he was "sad' with the car and "FURIOUS" having to spend that much on a battery- would the double negative energy rejuvenate the battery in a positive way?

---It's extremely well understood that battery longevity can be increased by avoiding the extremes of the charge range. This is done all the time computers (my Lenovo laptop has a "maximum longevity" setting where I can use half the battery capacity, and EV car companies have settings to program the maximum charge level.

You really have no grasp of the science in question do you? You also like red herring as none of this matters as you stray further and further into the generic when the focus is and always has been a 1:1 comparison with fossil fuels of the same payload in terms of performance. You keep repeating non sequitur comparisons as some type of justification of a non relevant point as if by some change the sheer volume of them may one day mean something.

---The guy who estimates it will last 20 years is a battery researcher. Elon Musk specifically recommends keeping a battery within 30-80%. There are various rules of thumb including 20-80% or 40-80% in order to maximize battery longevity. The battery researcher actually recommended 70%, which one Telsa owner is doing on his advice.

"The guy who estimates" now there's a new standard of science. Telling a story from someone with a vested interest in the outcome, there's a total lack of bias if I ever saw it.

---I have worked in engineering, and absolutely it's about coming up with solutions knowing the limitations of the technology. In my field the tradeoff is power, area, and cost
.
In what capacity and what discipline if I may ask?

 

[jhellwig]

Originally Posted by ABN_CBT_ENGR
Originally Posted by y_p_w

The city and highway eMPG of most electrics are about the same. How many charge cycles correlates extremely closely with the mileage.

When you've got a car on its original battery with over 200,000 miles with 90% of its capacity remaining, I'd say that's a pretty good indicator that the batteries last. However, someone with a depleted battery but otherwise happy with the car might be willing to spend $5000 on a battery replacement on a car that cost $50,000 new.

It's extremely well understood that battery longevity can be increased by avoiding the extremes of the charge range. This is done all the time computers (my Lenovo laptop has a "maximum longevity" setting where I can use half the battery capacity, and EV car companies have settings to program the maximum charge level. The guy who estimates it will last 20 years is a battery researcher. Elon Musk specifically recommends keeping a battery within 30-80%. There are various rules of thumb including 20-80% or 40-80% in order to maximize battery longevity. The battery researcher actually recommended 70%, which one Telsa owner is doing on his advice.

Quote
https://electrek.co/2017/09/01/tesla-battery-expert-recommends-daily-battery-pack-charging/
Jeff Dahn, a renowned battery researcher and the leader of Tesla's research partnership through his battery-research group at Dalhousie University, has been working on li-ion battery durability for Tesla for a year now.

He has been studying the impact of the charge and discharge rates on the lifecycle of Tesla's batteries.

https://teslamotorsclub.com/tmc/thr...on-long-term-battery-preservation.97134/
I decided to do a video on this as it's a fairly common question I've come across and hard not to get several different answers. So, I reached out to Jeff Dahn (Tesla Industrial Research Chair and Professor of Physics and Atmospheric Science at the University of Dalhousie in Nova Scotia). I advised I was planning to keep my X for approximately 2 decades and asked him where he'd charge the battery to for day-to-day use, with long term preservation in mind.

For those that don't wish to watch the video he recommends daily charging to 70 percent and to go ahead and charge to 100 percent for longer trips. He also comments on Vancouver being a nice climate for lithium ion batteries. Cheers.


I have worked in engineering, and absolutely it's about coming up with solutions knowing the limitations of the technology. In my field the tradeoff is power, area, and cost.


Holy dead batteries Batman, the farce is strong with this one

Here we go again, another failed attempt to try to pass off hyperbole and marketing claims as a legitimate science

---The city and highway eMPG of most electrics are about the same. How many charge cycles correlates extremely closely with the mileage.

It's a meaningless metric capturing meaningless data in terms of actual battery properties because this alleged "empg" changes DRASTICALLY with the type of vehicle, payload, other loads and so forth. Charge cycles depends on lots of variables. Once again, junk data from a junk science marketing plan

---When you've got a car on its original battery with over 200,000 miles with 90% of its capacity remaining, I'd say that's a pretty good indicator that the batteries last.

As stated, depends on a lot of things previously defined, this is too simplistic to be of any real value without knowing what all of them were in order to scale and qualify those claims.

---However, someone with a depleted battery but otherwise happy with the car might be willing to spend $5000 on a battery replacement on a car that cost $50,000 new.

Someone once said "hope is not a strategy" and "might" is hardly a measurable scientific finding. Is "happy" a factor in battery testing?

What if he was "sad' with the car and "FURIOUS" having to spend that much on a battery- would the double negative energy rejuvenate the battery in a positive way?

---It's extremely well understood that battery longevity can be increased by avoiding the extremes of the charge range. This is done all the time computers (my Lenovo laptop has a "maximum longevity" setting where I can use half the battery capacity, and EV car companies have settings to program the maximum charge level.

You really have no grasp of the science in question do you? You also like red herring as none of this matters as you stray further and further into the generic when the focus is and always has been a 1:1 comparison with fossil fuels of the same payload in terms of performance. You keep repeating non sequitur comparisons as some type of justification of a non relevant point as if by some change the sheer volume of them may one day mean something.

---The guy who estimates it will last 20 years is a battery researcher. Elon Musk specifically recommends keeping a battery within 30-80%. There are various rules of thumb including 20-80% or 40-80% in order to maximize battery longevity. The battery researcher actually recommended 70%, which one Telsa owner is doing on his advice.

"The guy who estimates" now there's a new standard of science. Telling a story from someone with a vested interest in the outcome, there's a total lack of bias if I ever saw it.

---I have worked in engineering, and absolutely it's about coming up with solutions knowing the limitations of the technology. In my field the tradeoff is power, area, and cost
.
In what capacity and what discipline if I may ask?





For Pete sake knock it off. You took this way out into the weeds.

 

[ABN_CBT_ENGR]

No I didn't, I asked legitimate questions based on comments ( like boards typically do).

Which bothered you the most- the directness and relevance of the questions or the lack of answers?

 

[JHZR2]

Originally Posted by y_p_w




Quote
https://electrek.co/2017/09/01/tesla-battery-expert-recommends-daily-battery-pack-charging/
Jeff Dahn, a renowned battery researcher and the leader of Tesla's research partnership through his battery-research group at Dalhousie University, has been working on li-ion battery durability for Tesla for a year now.

He has been studying the impact of the charge and discharge rates on the lifecycle of Tesla's batteries.

https://teslamotorsclub.com/tmc/thr...on-long-term-battery-preservation.97134/
I decided to do a video on this as it's a fairly common question I've come across and hard not to get several different answers. So, I reached out to Jeff Dahn (Tesla Industrial Research Chair and Professor of Physics and Atmospheric Science at the University of Dalhousie in Nova Scotia). I advised I was planning to keep my X for approximately 2 decades and asked him where he'd charge the battery to for day-to-day use, with long term preservation in mind.

For those that don't wish to watch the video he recommends daily charging to 70 percent and to go ahead and charge to 100 percent for longer trips. He also comments on Vancouver being a nice climate for lithium ion batteries. Cheers.


I have worked in engineering, and absolutely it's about coming up with solutions knowing the limitations of the technology. In my field the tradeoff is power, area, and cost.


I have met Jeff Dahn, Ive seen and reviewed his work, and find his capabilities at Dalhousie to be very interesting and useful.

I would agree with his recommendations, but first a bit of other discussion...

EV batteries are designed with excess margin. Depending upon design, and the "power to energy ratio" to be used, the battery will use a limited portion of its capacity range. For very high rate capable batteries that are smaller (e.g. HEV), the total utilized capacity might be 20% of the total installed battery. For a large BEV system the utilization will be 75-80% at least. FThe software can be programmed to show that range of SOC to be "0-100%", and vary in time. Thats why I always find it interesting when folks think Tesla's software pushes give them magic capabilities. Theyre looking real time in capacity and degradation rates, impedance growth, etc., and then allowing more capacity to be used. The mechanical/physical design is what it is. Theyre just unlocking some of the margin that the purchaser bought and was unable to access before.

I totally agree with Jeff on keeping it limited to 70%. This is related to the materials.

There are a few things that go on. When charging/discharging fully, you get a significant amount of stress and strain in the electrodes. Remember that Li-ion is an intercalation battery - ions go in and out of void spaces in the materials, as the simplest description. Go too high and you can get oxidation of electrolyte as well. Go too low and you can get copper current collector dissolution. Generally BMS systems can prevent these conditions, but in highly parallel cell groups, running at high rates, some cells can fall off at very high and low SOCs.

So charging slowly, to ensure good and even intercalation and minimize the chance for localized overpotentials or plating of Li metal (in worst-case scenarios) is desirable, and limit the total charge to prevent the higher voltage ranges and the worst stress/strain due to swelling of electrodes. The other side of this is to minimize the SOC variation. So the reality is that 70% max, and 50% min is probably best. One could quite possibly get tens of thousands if not higher number of cycles in a limited range like this.

Folks also need to realize that batteries do have a calendar life challenge separately. It is governed by Arrhenius. So high rate charge or discharge, and existing in higher temperatures will all increase the degrading side reactions, increasing impedance, SEI layer growth, and capacity loss overall. Keeping the battery in a narrow SOC will also mean that the user wont necessarily see the capacity loss. And that hits on another point. Once in a while, a full charge should be done. The battery balances when at full SOC, and the management system turns on resistors to pull down the highest cells/groups. Also, to some extent the management system is good to calibrate, by pulling down the SOC to a very low level. The state of charge vs voltage curve has a slope to it, and often the management systems like to calibrate along this curve, sometimes counting coulombs.

 

[Cujet]

Originally Posted by y_p_w


When you've got a car on its original battery with over 200,000 miles with 90% of its capacity remaining, I'd say that's a pretty good indicator that the batteries last.


There is no question that the expensive Tesla cars with their very expensive and large battery packs can achieve many cycles and therefore many miles of reliable service. I do wonder about the versions of EV's I can afford, with smaller batteries, higher daily depth of discharge and higher rates of discharge in "cruise flight"

(remember there is little difference in Watt Hours per Mile among various EV's, so the smaller batteries do experience a higher rate of discharge, therefore stress, one reason Tesla got away from the small battery packs)

Originally Posted by JHZR2


Folks also need to realize that batteries do have a calendar life challenge separately.


True! Time plays a major role in battery health, or lack thereof.




And therein lies my dilemma. While I don't expect to live forever, I do expect my vehicles to provide a full 2 decades of service. My current car was made in 2002, has 197,000 miles on it and shows no signs of early demise. Do we honestly expect today's lithium batteries to provide 20 years of service and still perform like new? I certainly don't. I've been wanting an EV, badly, as I absolutely LOVE the way they drive. But I am having a very hard time with the various limitations. I also know that despite the claims, they are not environmentally better, as best case EV is 29% fuel to wheel efficiency.



In the end though, we must realize that all EV batteries are "sandbagged" and when new, have a good bit more than rated capacity. 90% of original range is just a computer managed number.

 

[y_p_w]

Originally Posted by Cujet
Originally Posted by y_p_w


When you've got a car on its original battery with over 200,000 miles with 90% of its capacity remaining, I'd say that's a pretty good indicator that the batteries last.


There is no question that the expensive Tesla cars with their very expensive and large battery packs can achieve many cycles and therefore many miles of reliable service. I do wonder about the versions of EV's I can afford, with smaller batteries, higher daily depth of discharge and higher rates of discharge in "cruise flight"

(remember there is little difference in Watt Hours per Mile among various EV's, so the smaller batteries do experience a higher rate of discharge, therefore stress, one reason Tesla got away from the small battery packs)

Originally Posted by JHZR2


Folks also need to realize that batteries do have a calendar life challenge separately.


True! Time plays a major role in battery health, or lack thereof.




And therein lies my dilemma. While I don't expect to live forever, I do expect my vehicles to provide a full 2 decades of service. My current car was made in 2002, has 197,000 miles on it and shows no signs of early demise. Do we honestly expect today's lithium batteries to provide 20 years of service and still perform like new? I certainly don't. I've been wanting an EV, badly, as I absolutely LOVE the way they drive. But I am having a very hard time with the various limitations. I also know that despite the claims, they are not environmentally better, as best case EV is 29% fuel to wheel efficiency.



In the end though, we must realize that all EV batteries are "sandbagged" and when new, have a good bit more than rated capacity. 90% of original range is just a computer managed number.






Sure. Oversizing a battery and using less of its theoretical charge range is well known to improve how long it lasts. At least in Apple devices, they rate an iPhone battery for 500 "cycles" while their larger devices (laptops and tablets) are rated for 1000 cycles.

I guess batteries do "age" to some degree. However, it remains to be seen how well the electric motor lasts and whether ir might make sense to just replace a battery when its performance is poor. That certainly makes sense when replacing an iPhone battery costs $49, but you start thinking hard about it with a car when it will cost $5000 or more. When the range is only 60% of the nominal rating, it's still usable. I have heard of many batteries suddenly dying though once it's well past the nominal cycle rating.

 

[JHZR2]

The problem with that concept is the other things that can happen.

Loss of capacity usually goes hand in hand with higher impedance. Which means I^2R inside the cell, and this greater internal heating, gassing, and potentially release.

On crimp seal cells the gasket scan creep and electrolyte diffuse out.

If copper or lithium dissolve and then plate out, then you can form dendrites that cause internal shorts and major fires.

I love driving my 1981 MB. BUT I wouldn't drive a 39yo car with Li-ion batteries.

10 years is viable. Beyond that there are risks of different types, and they go beyond performance. When cars must be condemned due to safety, that's an issue.

The question will become if Li-ion becomes recyclable enough (lithium aside, it's primarily steel, copper, aluminum, nickel, cobalt and carbon), that the cel lines can keep pumping cells made of recycled materials, and the packs can be "repowered" in a smart way to make cost effective replacements every decade or so.

Problem is, it's still not cheap. Say the transfer cost of an 18650 is $2, and a 21700 is $3. A model 3 pack has around 4400 cells. That's $12k plus labor to repower after a decade. That won't fly.

 

[y_p_w]

Originally Posted by JHZR2
Problem is, it's still not cheap. Say the transfer cost of an 18650 is $2, and a 21700 is $3. A model 3 pack has around 4400 cells. That's $12k plus labor to repower after a decade. That won't fly.

Last year Musk claimed that a Model 3 battery replacement service should cost $5000-$7000. They make their own batteries, so maybe there's something different about their costs. The best way to do a factory replacement might be using rebuilt battery units where they just swap them out and send the old one to get rebuilt.

 

[JHZR2]

Originally Posted by y_p_w
Originally Posted by JHZR2
Problem is, it's still not cheap. Say the transfer cost of an 18650 is $2, and a 21700 is $3. A model 3 pack has around 4400 cells. That's $12k plus labor to repower after a decade. That won't fly.

Last year Musk claimed that a Model 3 battery replacement service should cost $5000-$7000. They make their own batteries, so maybe there's something different about their costs. The best way to do a factory replacement might be using rebuilt battery units where they just swap them out and send the old one to get rebuilt.


Their production cost might be lower - I just made a SWAG at the transfer cost per cell, knowing that you can fairly easily buy small cells as low as $3.50-ish these days, and so wholesale internal to a business should be lower.

Regardless, $5000-7000 is about on par with an engine replacement. But the difference is that the battery WILL need to be replaced due to calendar life degradation, which is a fact of life. An engine doesnt have a guarantee that this needs to be done. A battery effectively does - the outcome if risks are not fully mitigated in batteries is a significant release and fire. The worst-case outcomes are pretty different...

 

[y_p_w]

Originally Posted by JHZR2
Originally Posted by y_p_w
Originally Posted by JHZR2
Problem is, it's still not cheap. Say the transfer cost of an 18650 is $2, and a 21700 is $3. A model 3 pack has around 4400 cells. That's $12k plus labor to repower after a decade. That won't fly.

Last year Musk claimed that a Model 3 battery replacement service should cost $5000-$7000. They make their own batteries, so maybe there's something different about their costs. The best way to do a factory replacement might be using rebuilt battery units where they just swap them out and send the old one to get rebuilt.


Their production cost might be lower - I just made a SWAG at the transfer cost per cell, knowing that you can fairly easily buy small cells as low as $3.50-ish these days, and so wholesale internal to a business should be lower.

Regardless, $5000-7000 is about on par with an engine replacement. But the difference is that the battery WILL need to be replaced due to calendar life degradation, which is a fact of life. An engine doesnt have a guarantee that this needs to be done. A battery effectively does - the outcome if risks are not fully mitigated in batteries is a significant release and fire. The worst-case outcomes are pretty different...

I don't know exactly what Tesla or another EV maker's battery system does to mitigate fire risk, but obviously they work on that. However, the industry standard is that the nominal cycle rating is targeted towards 80% of the original rated capacity. Even with simple aging, that doesn't necessarily kill the battery. Even when it's under the standard capacity loss, it may still work, albeit with lower capacity and possibly lower performance. We saw that with the Apple battery throttling system. That was a matter of a risk of not supplying enough power to the point where the voltage to the circuit drops and in digital circuits that results in data corruption. But with an EV I'm not sure that they can't deal with that without requiring a total shutdown. I thought that the electronics are powered of a 12V system anyways.

Even if a battery still has 60% of its original rated capacity, that might be enough for some who just don't want to get a new battery. As for replacing, it remains to be seen how good the performance is of the vehicle as a whole after the battery is "depleted". It may be worth it if the electric motor is still solid and the vehicle is in good shape.

At the very least there are aftermarket reconditioned battery packs for the Model S. They may not necessarily be that great for someone who wants like new performance, but it might work for someone who doesn't want to spend too much after a catastrophic failure of the original battery pack. And you never know. Some batteries degrade linearly after reaching the typical 80% of original, but sometimes they can start losing a lot of capacity quickly at that point.

 

[ABN_CBT_ENGR]

Originally Posted by y_p_w


Regardless, $5000-7000 is about on par with an engine replacement. But the difference is that the battery WILL need to be replaced due to calendar life degradation, which is a fact of life. An engine doesnt have a guarantee that this needs to be done. A battery effectively does - the outcome if risks are not fully mitigated in batteries is a significant release and fire. The worst-case outcomes are pretty different...

I don't know exactly what Tesla or another EV maker's battery system does to mitigate fire risk, but obviously they work on that. However, the industry standard is that the nominal cycle rating is targeted towards 80% of the original rated capacity. Even with simple aging, that doesn't necessarily kill the battery. Even when it's under the standard capacity loss, it may still work, albeit with lower capacity and possibly lower performance. We saw that with the Apple battery throttling system. That was a matter of a risk of not supplying enough power to the point where the voltage to the circuit drops and in digital circuits that results in data corruption. But with an EV I'm not sure that they can't deal with that without requiring a total shutdown. I thought that the electronics are powered of a 12V system anyways.

Even if a battery still has 60% of its original rated capacity, that might be enough for some who just don't want to get a new battery. As for replacing, it remains to be seen how good the performance is of the vehicle as a whole after the battery is "depleted". It may be worth it if e electric motor is still solid and the vehicle is in good shape.th

At the very least there are aftermarket reconditioned battery packs for the Model S. They may not necessarily be that great for someone who wants like new performance, but it might work for someone who doesn't want to spend too much after a catastrophic failure of the original battery pack. And you never know. Some batteries degrade linearly after reaching the typical 80% of original, but sometimes they can start losing a lot of capacity quickly at that point.[/quote]

Question for you since you seem to have a great deal of depth of knowledge on this. If you know or can inquire.

I do industrial motors but never had the thought to investigate one of these so I'm asking.

What is the "locked rotor" max BHP draw for an EV motor? ( I mean the design max at SF of 1.0 or higher)

If that's known then that would have to identify whatever the low end power the battery must be able to deliver over time for the vehicle to function without degraded performance.

Thank you in advance

 

[y_p_w]

Originally Posted by ABN_CBT_ENGR
Question for you since you seem to have a great deal of depth of knowledge on this. If you know or can inquire.

I do industrial motors but never had the thought to investigate one of these so I'm asking.

What is the "locked rotor" max BHP draw for an EV motor? ( I mean the design max at SF of 1.0 or higher)

If that's known then that would have to identify whatever the low end power the battery must be able to deliver over time for the vehicle to function without degraded performance.

Thank you in advance

I don't know much about motors. I do digital electronics. I know just enough about batteries as a user of consumer electronics to be dangerous. I understand what happens to a complex digital circuit if the power rail sags too much. It's not recoverable due to soft errors. That's what Apple was trying to avoid with their throttling of their iPhone CPUs. They tried to keep it from ever getting to that point.

But absolutely batteries can be used after they reach the standard for being "depleted". Apple did it by deliberately backing off on maximum performance. What EV makers to do mitigate the effects of reduced battery performance is something they've researched. The easiest thing for me to understand was this article. It seems to be talking about "grace capacity", which is building in spare capacity (i.e. oversizing) into a battery that may eventually have to be tapped into as the battery loses capacity.

Quote
https://batteryuniversity.com/learn/article/bu_1003a_battery_aging_in_an_electric_vehicle_ev
The secret of longevity in the EV battery is oversizing and only operating in mid-range with plenty of "grace capacity" as spare in the upper and lower bands. Partial use reduces battery stress, but leaves valuable energy storage under-utilized. Oversizing also adds cost and weight, but this spare capacity will eventually get used when the capacity fades.

Charging the battery to only 80% and discharging to 20%, as is typically done on a new EV battery, only utilizes 60% of the capacity. As charge acceptance fades with use and time, the onboard BMS demands a higher charge and a lower discharge to meet the driving range. This adjustment remains unnoticed by the driver until a reduction in driving range is noticed. This occurs when the "grace capacity" is consumed.

Theoretically, depletion requires a full charge and full discharge to meet the energy requirements. At this point, battery stress increases and capacity fade accelerates, resulting in reduced driving range. This change is predictable and evolves over a few years of driving. Once the battery capacity has dropped to 70%, the EV can still be used for short commuting and errands. In most cases, capacity fade only reduces the driving range while power remains strong.

The mobile phone does not apply grace capacity to prolong battery life. In the interest of small size and long runtime, the battery is fully utilized from the beginning. From the user standpoint, it best not to discharge the mobile phone too deeply but charge it more often. Battery life can also be prolonged by a partial charge, but most chargers do not have a provision to set the charge limit. End-of-charge will need to be controlled manually. Phone manufacturers build in obsolesces that often correspond with a broken touchscreen or the desire for new features.

It seems pretty simple that oversizing a battery is how one can maintain performance even after the battery is depleted.

 

[ABN_CBT_ENGR]

Originally Posted by y_p_w

It seems pretty simple that oversizing a battery is how one can maintain performance even after the battery is depleted.


Doesn't work that way on an electric motor.

The motor (working device) has a minimum load ( volt and amp) to turn itself and work/cool- that load is relative to the HP rating and requirement of said motor. ( which is why motors pull more amps generally under various loads)

Unlike lights and other electronics- motors have a minimum operating requirement that's go or no-go and its not debatable.

So, theres a low-low threshold (LL being defined as minimal requirement to turn just to function) and if battery cannot meet this then motor just sits, hums and heats until bad things happen I any one of various low voltage burn out scenario's.

Then theres the low threshold where said battery can provide the minimum amount of power to perform "work" but its at the lowest end of the scale ( this would be relative to the driven device requirement)- you "may" have touched on this in your comments above about 'short trips".

So if you will, any idea where or how those 2 things can be found?

In all honesty, those 2 things will determine whether a battery can meet the demand or not. ( demand defined as the full payload utilization of the vehicle in question regardless or make, model or manufacturer)

Thank you

 

[y_p_w]

Originally Posted by ABN_CBT_ENGR
Originally Posted by y_p_w

It seems pretty simple that oversizing a battery is how one can maintain performance even after the battery is depleted.


Doesn't work that way on an electric motor.

The motor (working device) has a minimum load ( volt and amp) to turn itself and work/cool- that load is relative to the HP rating and requirement of said motor. ( which is why motors pull more amps generally under various loads)

Unlike lights and other electronics- motors have a minimum operating requirement that's go or no-go and its not debatable.

So, theres a low-low threshold (LL being defined as minimal requirement to turn just to function) and if battery cannot meet this then motor just sits, hums and heats until bad things happen I any one of various low voltage burn out scenario's.

Then theres the low threshold where said battery can provide the minimum amount of power to perform "work" but its at the lowest end of the scale ( this would be relative to the driven device requirement)- you "may" have touched on this in your comments above about 'short trips".

So if you will, any idea where or how those 2 things can be found?

In all honesty, those 2 things will determine whether a battery can meet the demand or not. ( demand defined as the full payload utilization of the vehicle in question regardless or make, model or manufacturer)

Thank you

The digital electronics will fail in spectacular fashion if the voltage drops. However, those are going to be powered off of a separate 12V system, which is going to have to stay operating or else all the controls are gone. And the actual electronics operate off of an even lower voltage.

But reading as to how the system works - yeah they do all sorts of things when the battery weakens. This states that some who take a Tesla to a track usually make sure it's fully charged for the highest performance. Make sense. It doesn't sound like a bad thing. It's just dealing with the reality.

https://forums.tesla.com/forum/forums/model-s-acceleration-slower-battery-depletes