Tesla Range Question

[ajdelange]

When I screwed up and put in 600 rather than 500 which is, of course correct. And then repeated the error in the second paragraph but got it right in the third. Thanks for catching that. I'll fix it. Sorry about that folks! I know it's confusing enough with out me leading you astray.

Advertisement

 

[TerryMack]

Here's a table that shows range vs speed for various trims and wheels https://teslike.com/

Dude, Nice informative Link!!!

 

[israndy]

I am curious what the original poster was asking. If you are trying to get 300 miles of range on a car with an EPA estimate it is definitely possible. My 70 MPG Honda Insight has given me 93.5 MPG on long trips of about 900 miles on a single 10-gallon tank.

BUT, can I MAKE the car get 70 MPG by doing ONE thing? No.

Same with the Tesla, I use AutoPilot and I have the car set to go 8 MPH over the speed limit if possible and EVERYWHERE I drive I get less than the EPA rating for range on the car. Yet those guys in Colorado did a giant loop for a day with people tossing food in their window as they passed and no AC running and they got over 600 miles of range. So perhaps somewhere in there, one could get 310 miles out of a Model 3, but

1) your battery is dead so how are you going to get to the Supercharger and
2) if a gust of wind came up it would screw your calculation

So really just pull off when you are told to by your nav system. Keeping up with traffic and having a comfortable interior is much more important.

 

[ajdelange]

I am curious what the original poster was asking.

He asks some pretty specific question. I don't automatically see all the posts so I didn't address them but here goes:

I see many companies using different speeds for range estimates. Those of you who own Teslas, what is the speed that gives you the advertised range?

Without going into a lot of statistical gobbldygook I will just say that based on my driving history the averagae speed that gives me closest to the advertised range is 38 mph but that the probability that I actually acheive the advertised range is a fraction of a percent. But I have logged 13 drives with average speeds up to 55 mph which gave me better than the advertised range.

Does the vehicle change the expected distance remaining based on your speed? For example, if you are doing 70MPH, and you slow to 55MPH, does the vehicle instantly tell you what your remaining distance will be at the lower speed?

Only if you have the energy display set for "Instantaneous". Other wise it will use average consumption in whichever window you have chosen (the past 5, 15 or 30 miles).

If you have a destination set in the navigation system, will it also figure out expected usage based on climbs and descents?

Yes if you are on the right page. It uses the past 5, 15 or 30 miles driving history and what it knows about the terrain ahead to predict destination SoC.

So really just pull off when you are told to by your nav system. Keeping up with traffic and having a comfortable interior is much more important.

I tried to explain under "Major Point" in No. 4 that the driver's most valuable display IMO is the one that shows the original estimated battery use over the trip distance, the actual use up to the present position and prediction of use from the present position to the destination and the estimated SoC at destination. I monitor this graph while driving. As long as I am comfortable with that destination SoC number I keep going. If it gets too low I stop and charge.

 

[Newton]

I know lithium batteries like to sit between about 20-85% charge. (to prevent degradation)

Is the range estimations 100-0%?

 

[ajdelange]

Yes but the tricky bit is that the location of the 0 and 100% marks are rather arbitrary and set by the manufacturer and do not reflect the true capacity of the battery. If you take two new batteries and charge them at the same rate but start one a little earlier than the other and stop charging the second when the first is ruined you and then discharge the second until it is ruined then you have a pretty good idea of what the absolute capacity of the battery is. In any practical application you might put the full and empty marks say 10% above the low end destruction level and 10% below the upper destruction limit. Now the manufacturer can move those marks a percent closer to the damage limits and pick up 2% range (with perhaps, the caveat that one should never charge above 99% or discharge below 1% etc. But the range of the vehicle is based on the empty and full marks - not the absolute capacity.

It get's more complicated than this since capacity is the number of lithium ions that can move between anode and cathode but it takes or evolves different amounts of energy to do that depending on things like charge/discharge rate and temperature and clearly we deal with Wh/mi and kWh charge rather than amperehours per mile or ampere hour charges. Thus we never have a terribly precise picture of our batteries' SoC. It is never, for example, shown to us with more than 2 significant figures precision.

 

[Newton]

ok, I assumed tesla made the 0 and 100 percent marks somewhere at like 5% and 95%.
but like you said, it could be at 1% and 99%. Its kind of anoying they dont just tell us.
I always hear "you should avoid charging past 80%". I guess the vehicles manual is best to default to.

 

[ajdelange]

Its kind of anoying they dont just tell us.

They are quite careful to insure that we don't have the complete picture. The API used to report battery current but mysteriously stopped doing that.

I always hear "you should avoid charging past 80%". I guess the vehicles manual is best to default to.

Yes, by all means!

 

[ricinro]

Keep in mind that the 500 miles range for the TriMotor was calculated with the new battery technology "priced in" by which I mean the engineers worked from a set of battery numbers projected from the lab studies of the new tech.

Much more important is to understand that the 500 mile number is, in the case of the CT, that of the vehicle by itself - the way in which it will be operated the majority of the time. While it is no more possible to predict loaded range accuracy than unloaded there will certainly be a dramatic drop in range when a trailer is connected. With an unloaded "working range" of a TriMotor with no trailer attached being around 375 miles the working range of one pulling the maximum load is going to something like half of that. (187 miles).

With the Semi, conversely, the range is specified for maximum load. Thus the 300 or 500 mile numbers imply working ranges of 225 or 375 miles loaded. These are not adequate for long range trucking thus the Semi will serve the partial load shorter range market (e.g. a outlet chain moving product from one warehouse to another or a warehouse to a store). The long haul jobs will require something like what Nikola is promising.

"Keep in mind that the 500 miles range for the TriMotor was calculated with the new battery technology "priced in"

This is something I also believe. If Tesla contacts reservation holders next year or so and tell them the CT is actually 20-40% more expensive than originally advertised or range is half of what was advertised this would make sense considering this is a truck and not a sleek small sedan. The only variables to achieve to CT range/pricing was better battery tech and advanced manufacturing tech that can shave 20% off the cost of producing a truck. So, to me, the secret is in better battery tech.

 

[Aces-Truck]

I *think* the OP was trying to understand if a dual motor version (300 mile range) would have enough range for some driving scenarios he's likely to see. A relative bought an early Leaf, which claimed 85 mile range. He wanted to be able to drive to his sisters house, which was right about that distance. He could never do it. He recently bought a Bolt EV, which solved it. But the real question is if you had a 300 mile range CT, could you reasonably be able to drive 250 miles in the Winter? in hilly country? Knowing an answer like this might be the difference between opting for a Tri Motor; or even abandoning the idea of a CT.

 

[Jhodgesatmb]

I believe that the range Tesla offered when they announce fed the CT had to be based on the battery technology they had at the time, not the battery technology they ‘might’ have when the truck is manufactured. The latter would be a huge risk. So. Janowicz do. You guys know that Tesla meant the upcoming batteries and their specs? Because they couldn’t get 500 miles on the current technology? Even with the 200 KWH batteries you were all talking about a couple months ago? So much for the guessing game, we’ll find out in a few weeks, maybe.

 

[Crissa]

But the real question is if you had a 300 mile range CT, could you reasonably be able to drive 250 miles in the Winter? in hilly country? Knowing an answer like this might be the difference between opting for a Tri Motor; or even abandoning the idea of a CT.

A Tesla has the least winter penalty of any EV, since it actively heats and cools the battery pack. However, cold air, wet roads, cabin heating, headlights - this all is a drain on your battery power. So you can consume 50% to 100% more power than in more moderate weather. It will vary by driving style and environment.

-Crissa

PS, ICE cars also suffer these reductions, but you rarely notice it since you can utilize the waste heat from the engine. In truth, ICE vehicles have a 'summer penalty' that no one thinks about, since they have to keep themselves cool.

 

[ajdelange]

They will advertise prices and performance using the materials and assembly techniques they expect to have available at the time of manufacture. That's only prudent. "Expect" means just that. There is always risk and thus "expect" means that the risks are low and that they have a backup plan. The batteries they will specify are those that they have been working on in the laboratory for years and that they have tested thoroughly in the lab and run around extensively in test vehicles. The improvements we are going to hear about on the 22nd will not be excluded from the CT. The batteries we are going to hear about on battery day will be the batteries that will go into it. Probably. We know nothing for certain so we can only guess at what a prudent businessman would do.

Now Mr. Musk is definitely a showman. I wouldn't faint if he announced that the battery program has gone better than expected and the TriMotor will indeed have 600 mi range but I think he'd be more likely to keep any dramatic improvement in energy density under his hat and convert it to extra profit.

 

[ajdelange]

Interesting that just today and yesterday there is talk of the nanowire anode (and there has been previous chatter about the anode-less) battery. Must is stating publicly that 400 wH/kg may be possible on the factory floor in as little as 3 or 4 years. Note that if such a battery were available today it would boost the MX range from 351 to 540 miles. We probably won't find that battery in the CT, at least not the earliest ones but note that Musk saw fit to mention this tech a month ahead of battery day. Would this have anything to do with the press reporting that Lucid claims 400 miles? Note: Lucid doesn't claim 500 miles - they claim 400.