Electric Car Prediction - Whatdayathing???

[BeauV]

I’ll need to research this more, but I just found this: “A mature tree absorbs carbon dioxide at a rate of 48 pounds per year. In one year, an acre of forest can absorb twice the CO2 produced by the average car's annual mileage.”

Source: http://www.tenmilliontrees.org/trees/

Fun to think about.

[BeauV]

Interesting survey article on ways that folks are trying to lower the carbon footprint of boat building HERE

I especially enjoyed the melted basalt rock fiber and learning that 250,000 tons of fiberglass (that can't be recycled) is put into landfill each year in the EU.

[SemiSalt]

I’ll need to research this more, but I just found this: “A mature tree absorbs carbon dioxide at a rate of 48 pounds per year. In one year, an acre of forest can absorb twice the CO2 produced by the average car's annual mileage.”

Source: http://www.tenmilliontrees.org/trees/

Fun to think about.

I've gotten the impression that some climate change thinkers are dubious about how much planting trees can help in the very long run. Forests can store a lot of carbon, but is a limited depository. Wood goes back to carbon dioxide in, I guess, less than two centuries.

OTOH, our current predicament is all the worse for deforestation, especially the Amazon jungle.

[avramd]

In case anyone is interested, I have an update on my Model Y's apparent significant range loss situation. The situation has turned around in a surprisingly unexpected way.

Background: When the car was new about a year ago, it rated itself at 313 miles of range. This is just a way of expressing battery capacity that is relatable, it's based on a fixed estimated kWh/mi for a given model. By Aug I was down to 295, and Nov, 282. That's a 10% range loss. I had about 16k mi on the car at that point. Much of that loss was rather sudden like 5 or 10 miles between one day and the next.

In conversations with Tesla service, somebody said to me: "Do you normally plug your car in to charge when the charge level is above 40%?" I said yes, I pretty much alway plug it in when I'm below 80%. He said "Try letting your charge run down to 40% or below on a regular basis before plugging it in. This does not affect your true range, but it gives the car a wider range of battery data, and that enables it to better estimate charge capacity. If you do that regularly, you should start to see your estimated range creep back up."

Well sonovagun, he was right. That was mid December, and my battery capacity has been "creeping" back up at a surprising rate. Check out the graph below, particularly the latest trajectory. The low point there is the end of Nov. Since then, I'm back up to 295 rated miles, and with luck it's not done recovering.

[BeauV]

Avramd, that's great news and it makes sense. Lithium batteries are extremely hard to predict from just the battery voltage plus voltage-under-load. There is a cliff in voltage when a lithium battery is about to go to nothing, entirely different from the relative slow voltage decline of Lead-Acid either wet or AGM. This gives the 'puter more data and it can avoid mistakenly predicting the edge of the cliff.

I will say your post is a bit "creepy". LOL

[BeauV]

I’ll need to research this more, but I just found this: “A mature tree absorbs carbon dioxide at a rate of 48 pounds per year. In one year, an acre of forest can absorb twice the CO2 produced by the average car's annual mileage.”

Source: http://www.tenmilliontrees.org/trees/

Fun to think about.

I've gotten the impression that some climate change thinkers are dubious about how much planting trees can help in the very long run. Forests can store a lot of carbon, but is a limited depository. Wood goes back to carbon dioxide in, I guess, less than two centuries.

OTOH, our current predicament is all the worse for deforestation, especially the Amazon jungle.

Semi - I agree that if one builds something in wood, or grows trees and lets them die of old age, or heaven forbid grows them for firewood, then there isn't much of a gain only deferral.

Key to a boat is that with the right "disposal", the wood could remain at the bottom of the ocean or in the mud of a river or slough for centuries. I'm obviously not thinking "Viking Funeral" here with the boat burning away. I'm thinking filling it with scrap metal or concrete and pulling the plug in 1,500 deep water. (Currently illegal, BTW)

[BeauV]

Well, whatdoyaknow! I finally got past the article on Edward Burgess in the Nov/Dec Wooden Boat magazine and there is an article called "Life-Cycle Analysis" by Richard Jagels. In it he reviews the various methods of building a boat for their life time environmental footprint. He Compares Aluminum (the worst), Fiber Glass with a core (second worst), Imported Wood (second best), and Local Wood (the best). While I'd thought there was an advantage to local wood, as I mentioned above, I never believed it would be about 5x better than Aluminum and 4.9x better than Fiberglass with core.

I can't figure out how to get you all access to the issue (paywall in the way), So I just took a picture of the radar chart measuring the various factors. The author lifted it from someplace called the "International Journal of Life Cycle Assessment" whoever that is.

[avramd]

Beau,

What is the distinction between Figure 3 and Figure 4?

Regardless, it is melting my brain that the one axis that aluminum boats are not worse than the alternatives is metal depletion !

[BeauV]

Beau,

What is the distinction between Figure 3 and Figure 4?

Regardless, it is melting my brain that the one axis that aluminum boats are not worse than the alternatives is metal depletion !

If memory serves, it's the impact of building the boat in Figure 3 and the total lifetime impact in Figure 4. Although I'm not certain and can't seem to find the source document. The reason Alloy boats win on total lifetime is that aluminum is easily worth the cost of recycling, while fiberglass has no recycle value. Iron or steel boats aren't worth recycling because the metal is plentiful and there's a lot of cost to recover the raw material.

[avramd]

Well, I jinxed myself. My battery range recovery did in fact hit the ceiling right after I posted my progress. I've had 4-5 charges in a row where my battery capacity estimate didn't increase. So I think that's it, ~295-297 miles of range, down from 313 when the car was new; about 5% range loss in 13 months and 17k miles.

I'm comfortable with that degree of degradation, especially considering I did have 2-3 100% charges and a couple of super-low discharges in there, and now I have a better idea how important it is not to do that.

hit-a-wall.jpg

[BeauV]

Avramd -- I'm pretty sure that the battery capacity is set for a benign weather place like California and perhaps is even more optimistic than that. The degradation indicated after the recovery may be climate-related. As you know, all batteries hate cold weather, and Tesla uses battery power to warm up the batteries to get more range. While that's not a dumb idea, it does reduce the expected range. You might watch the range during macro changes in weather, like waiting to measure again next spring before you're running the AC hard all the time and after the outside air temp has warmed up substantially.

[avramd]

Hey Beau,

Actually, the bigger drops in range here were in October, precisely the season around here when you don't need to pre-warm or pre-cool the car. However, as you presumably extracted from the above, most of that loss was false, and was in fact an estimation flaw, not actual range loss. The estimation recovery has remained tapped out, and now in mid winter I may well be experiencing real climate-related loss. However the idea is to be pre-warming the car while it is plugged in... but my experience so far is that the car is still short a few miles after pre-warming, even when plugged in. It seems extreme to me that the car would use >48 amps for pre-warming.

Avramd -- I'm pretty sure that the battery capacity is set for a benign weather place like California and perhaps is even more optimistic than that. The degradation indicated after the recovery may be climate-related. As you know, all batteries hate cold weather, and Tesla uses battery power to warm up the batteries to get more range. While that's not a dumb idea, it does reduce the expected range. You might watch the range during macro changes in weather, like waiting to measure again next spring before you're running the AC hard all the time and after the outside air temp has warmed up substantially.

[BeauV]

The thermal management on Tesla cars is extreme and complex. I don't pretend to really understand it, but I'm glad it works as well as it does. I get that when charging, the batteries get hot. But, it appears the charge acceptance is better when they are hot. After 65,000 miles and lots of hard use, our Model S appears to have nearly the same range it had when we bought it. Looking back, if memory serves we've lost about 10 miles of estimated range. We're very careful not to run the batteries all the way down.

BTW - we sold the Model X when I got my new "toy car". So, we're down to one Tesla now. No waiting at the charging cord. This was just in time to see gasoline prices spike, but whatever.

[avramd]

One thing that really surprises me is that the Model Y has a heat-pump, supposed to be much more efficient than resistive heat - especially when it's not too cold, and it still takes a few miles of range to pre-warm the car when it's 40º out. You'd think a resistive-heat car would have an even bigger deficit, but I've never heard any other Tesla owners saying they lose range when pre-warming plugged in.

The thermal management on Tesla cars is extreme and complex.

BTW - we sold the Model X when I got my new "toy car". So, we're down to one Tesla now. No waiting at the charging cord. This was just in time to see gasoline prices spike, but whatever.

Wait, what's the new "toy car?" I must have missed it!

[Steele]

I do not own a EV, but it appears a lot the battery capacity data is based on algorithms, not real time measurements. This reminds me of my Balmar "smart" battery monitor that tells me my 10 year old AGM house bank has a 100% capacity (what they call state of health) compared to new. In my case I have not had enough deep discharges for it to learn the characteristics of the battery.
Do Teslas display data such that you can monitor amp hours and battery capacity over a limited periord of time? That might allow you to compare data over similar trips like a work commute and figure out what is going on. With all the variables like traffic, temperature etc this would be something to average year to year rather than day by day.

[BeauV]

I do not own a EV, but it appears a lot the battery capacity data is based on algorithms, not real time measurements. This reminds me of my Balmar "smart" battery monitor that tells me my 10 year old AGM house bank has a 100% capacity (what they call state of health) compared to new. In my case I have not had enough deep discharges for it to learn the characteristics of the battery.
Do Teslas display data such that you can monitor amp hours and battery capacity over a limited periord of time? That might allow you to compare data over similar trips like a work commute and figure out what is going on. With all the variables like traffic, temperature etc this would be something to average year to year rather than day by day.

My "source" within Tesla quit and is now working on a battery-operated drone that will serve as an air taxi for four folks. Fully automated. It's busy flying around and avoiding trees and mountains all on its own. Amazing to watch. This leaves me without any "inside info", but all that was mostly just entertaining.

Back to your question. From what I've observed, there is some link between the routing software that comes with the Tesla and the forecast range. For example, it knows if I'm going over a big hill (1,800' pass) and reduces the "range" expectation as soon as I enter the destination. I also have noticed that when the outside air temp rises and the AC for the passengers (and the batteries) has to work harder, the software changes its forecast. As you point out, there are so many different variables that it's nearly impossible to "forecast" range.

BTW, in the Porsche, the "forecast" of the range uses the last 30-50 miles of driving as the "mileage" and the fuel gauge for the energy supply for the calculation. This gives some really weird results as the "around town" mileage is about 15 MPG, while the "fast highway" mileage is around 30 MPG. Hop off the freeway after a 100 to 150 mile run and fill up, it'll tell you the car has 460 miles of range. Fill up after driving around town and fill up, it'll tell you the car has about 380 miles of range.

All this "range forecasting" stuff is really inaccurate. It's a great example of people confusing precision for accuracy. The "forecast" looks highly precise and folks worry about single-digit alterations. But all you need to do for a 15-20 percent change is put a lead-foot driver like me in the car.

[avramd]

I actually laughed out loud when I read this:

Do Teslas display data such that you can monitor amp hours and battery capacity over a limited periord of time?

It is a great idea, and a perfectly valid question. The reason I laughed is that Elon barely trusts us to drive down the street without needing him to save us from ourselves. The lack of access to useful information and control in this car is hard to stomach. You can display your battery capacity in "range" or "energy." However both of them are euphemisms.

As Beau said, the car is surprisingly sophisticated at predicting actual range based on both observations and data such as temperature and elevation variation along your route, etc. However that has nothing to do with the units on the battery charge state gauge.

When the battery charge state gauge is in "range" mode, it is ironically showing you its estimate of the battery's stored energy, but in units that we call "rated miles." A "rated mile" is the number of Watt-hours that Tesla has chosen to represent the model's efficiency. For my car, I believe that is 287 Wh. I think this would come true at around 55mph with almost no acceleration, deceleration, or hills, on probably a 70º day. If I switch it to "energy" mode, it stops showing actual energy, and instead switches to units of %. This is the car's current estimate of its current charge state as a % of its current estimate of its maximum possible charge state. It is constantly adjusting both of these estimates.

I should have clarified in my previous post, when I said I find it frustrating to pre-heat my car while it is plugged in, and come out to find it a few miles short, what I mean is that its estimate of the battery's charge state should not change if it was truly preheating my car from shore power. I mean house power. Or, if it is going to change, it should get better, not worse, as the battery warms up.

[BeauV]

Avramd -- In a relatively recent release of the Tesla software on our Model S, there is a way to schedule the car to be "ready by __" where you set a time. I've found that the car has the battery charged up to the requested target and the battery stack seems to be warmed up. I don't know if the warming is an artifact of the charging or if it is pre-heating the battery stack. You might want to dig into this.

[Steele]

I think Tesla has written their code to accommodate the average car driver. This site is weighted towards engineers, scientists and tinkerers. Since we are boat owners this is not a surprise. Keep in mind a growing number of buyers no longer even test drive a car before purchasing it. As more of the population consider cars as appliances the manufactureres will accommodate them by making them as plug and play as possible.
I read recently that one of the reasons SUVs have risen in popularity is that younger people are not buying cars. They are no longer part of the car culture that dominated my teenage years. They therefore skip the small and inexpensive vehicles we started with and then purchase that 3 row trucklet when they move to the burps and have kids.
It is too bad companies like Tesla and Apple don't offer the option of digging into the details of how their products work for the benefit of knowledgeable owners like you and Beau. I think part of this is safety. I grew up changing my own oil, figuring out how a timing light worked and even trying to do my own brake work. The last was a bad idea, have you ever seen the wheels of a 74 Capri glow bright red after a 18 year old worked on his own master cylinder? I shudder to thnk about what would happen if my teenage self had access to the potential energy stored in a Telsa battery.

[TheOffice]

Steele,
In high school I had a choice between auto shop and physics. Took auto shop and never regretted it! I also changed oil, gapped plugs, timed engines, changed alternators and starters, did brakes and even rebuilt a master cylinder. I hated gapping points. When the boat mechanic was working on my dad's boats I hung around and asked questions. Some of those skills are transferrable to the boat, but I don't even think of working on my own car unless it is a flat tire.
Joel

[BeauV]

Steele -- you're exactly right. The _only_ one of my four kids who has ever lifted a wrench is the Marine, who replaced the shock towers, rebuilt the head, and a mess of other things on his Audi. He is the last of his generation, according to him. The Marine Corps allows the grunts to work on their own vehicles at the base. Complete lift, tools, old master sargents to answer questions, and even a tank or humvee to work on. The rest of my kids and my wife aren't qualified to check the oil, so I do it. My lovely Admiral was stunned that I pulled the starter motor off the Morgan in 4 minutes, she thought it would take hours. sigh...

[Olaf Hart]

To be fair, cars have become a lot harder to work on, I am just past my limit on the 07 VW Multivan, have given up on the AC, electric sliding door and entertainment system, its difficult enough just keeping up with the codes.

OTOH the old Volvo penta 2003 began flashing an overheat warning light on the weekend, was able to track that down to faulty wiring to the sender in two minutes, had it fixed in ten minutes.

[Steele]

To be clear I was never a good mechanic, it was mostly trial and error with a heavy emphasis on the latter. Like Joel I have not worked on my own car for years, partly because they have become so complex. Having said that something as simple as my replacing a car battery seems to surprise people. I do it myself since it is so much quicker than dealing with the repair shop.

A recent example of the over-complication of cars is the lack of dip sticks. Neither our Audi or a friend's Porsche has one. You have to rely on an idiot light and have no real idea how low the oil really is. We recently had our's in for routine service and the low oil level light came on a week later. I am pretty sure when changing the oil the shop adds oil until the light goes out, but with no way to know how much is really in there they filled it barely enough. The Porshce's light came on a few months ago so our friend added a quart but the light stayed on. With no way to know why he took it to the dealer who discovered the oil level sensor was bad and the actual oil level was now too high. Two weeks ago it came back on and again the light did not turn off after adding a quart. Back to the dealer they went, this time to discover the sensor was fine and it was 3 quarts low. They are still trying to sort out why it was so low, but the lack of a simple dipstick almost caused a catastrophic failure.

I guess a benefit of EVs is the lack of things like oil changes, coolent leaks, exaust systems rusting away, timing belts, transmission issues etc.

[BeauV]

Steele -- our new Porsche has no dipstick, but the gauge on the dashboard shows you how full or empty it is. That won't solve a "bad sensor" problem, but it let's you know how much to add. Also, our Porsche will let you know that you have 5 miles to drive and get oil before the engine will turn itself off. THAT bit in my manual got my attention. I often drive across Nevada to visit Jackson Hole. I guess I'll take a LOT of oil because it's about 150 miles between gas stations on Route 50.

[Steele]

That would be a great upgrade. The Audi’s is a low oil warning that pops up on the infotainment screen with no other data. The Porsche is a 997.2 and I don't think it has a gauge either.
I sometimes worry about absolute actions like shutting down the engine, or an EV shutting down to avoid damaging a very low battery. Although very unlikely you could be in a situation where you might be willing to risk sacrificing the motor, such as a railroad crossing, or over the crest of a hill on a 2 lane highway at night. At least you have a gauge so you can be proactive to avoid the risk of something like that ever happening.
A corollary of this are the people I sometimes see changing a tire at night on the side of the freeway. I was taught early on that in a bad stiuation it was best to keep driving until you were safe, even if that meant destroying a wheel and tire.

[BeauV]

That would be a great upgrade. The Audi’s is a low oil warning that pops up on the infotainment screen with no other data. The Porsche is a 997.2 and I don't think it has a gauge either.
I sometimes worry about absolute actions like shutting down the engine, or an EV shutting down to avoid damaging a very low battery. Although very unlikely you could be in a situation where you might be willing to risk sacrificing the motor, such as a railroad crossing, or over the crest of a hill on a 2 lane highway at night. At least you have a gauge so you can be proactive to avoid the risk of something like that ever happening.
A corollary of this are the people I sometimes see changing a tire at night on the side of the freeway. I was taught early on that in a bad stiuation it was best to keep driving until you were safe, even if that meant destroying a wheel and tire.

In my 996 Porsche, there was a dipstick. The dealers said that low oil level was the #1 cause of engine failure, as Porsche engines are basically oil cooled; despite their addition of a bit of water cooling in recent decades.

Some folks value their rims higher than their safety -- some folks are just too stupid to realize they shouldn't do auto repair on the freeway. I've basically given up on trying to help people learn the obvious. Having been told to go-to-hell too many times when I'm trying to be helpful. sigh....

[SemiSalt]

I watched a video of a UK car show where they had a fleet of about 10 EVs and drove them until the battery was empty and would go no further. They had a sequence of limitations as the end approached. First, can't go over 60, then not over 30, then not over 15, etc. Plenty of time and distance to find a safe place to stop.

[Steele]

That makes sense. I have no experience with EVs so I envisioned they were like my lithium battery flashlight. It works great until the instant it doesn’t.

[kdh]

Steele -- our new Porsche has no dipstick, but the gauge on the dashboard shows you how full or empty it is. That won't solve a "bad sensor" problem, but it let's you know how much to add. Also, our Porsche will let you know that you have 5 miles to drive and get oil before the engine will turn itself off. THAT bit in my manual got my attention. I often drive across Nevada to visit Jackson Hole. I guess I'll take a LOT of oil because it's about 150 miles between gas stations on Route 50.

We just got back from Jackson. Adele's school break.

Snow was not fantastic but conditions for an east coast skier were still great. Loved the Grand Targhee resort over the pass, mostly because it was so open with few people there. Even Snow King has been tamed a bit so the steeps at the top can be avoided on your first run. Splurged and stayed at Amangani. Loved it.

Highlight was N Maine last week though taking my cousin's dog sled team out.

IMG_0305.jpeg

[BeauV]

Keith,

Oddly, I've only ever done dog-sledding in Jackson, WY. we went way back into the park in mid-winter. It was beautiful! I'd forgotten how much I enjoyed that.