Distraught by rapid loss of maximum battery storage

[ajdelange]

I see absolutely horrible numbers often. Trouble is the car doesn't really report numbers you can rely on.

You certainly can rely on them but you have to know how to interpret them.

Let the car sit for two days and how many kWh is acceptable for it to drain away? I've never seen anything from Tesla.

Tesla doesn't know what's acceptable to you. The median rate for the X seems to be about 0.3 mi/hr equivalent to a bit under 100 W or about 2.4 kWh/da. If you want the information collected by third party apps that poll the vehicle you will have to expect to pay that (I think most owners use at least one of these apps). 2.4 kWh costs me about $0.13/da. That's worth it to me.

I had trips where the average Wh/mi was good, like 333 or less (better than the EPA numbers)

That's not particularly good. The median for the X seems to be about 359 (the EPA rating is 316).

and yet I couldn't go further than 200 miles without nearly running out of juice.

At 333 you should be able to go 200 miles on 68% of your battery. If you can't go that far with a 68% charge then you aren't getting 333 Wh/mi. The various odometers and energy displays are in your vehicle to tell you what is going on. Learn to interpret them and you will have few surprises. Of course they cannot predict an un forecast thunderstorm (takes my X's consumption from right around 300 to over 400) or headwind but will tell you what your charge status is going to be at destination shortly after you encounter them.

In my ICE truck I know how far I can go and there just aren't many variables that impact mileage significantly.

No, you don't. Rain and headwinds effect ICE vehicles in exactly the same way they effect electric vehicles. The difference is that you can pull into a gas station anywhere when petrol gets low and you cannot (as yet anyway) do that in a BEV.

In my X it seems like I have no way to know what to expect other than purely highway trips on a single day.

Looking at the date you joined the forum it looks as if you have only had the car a month or so. When you learn how to read the displays, if you do, then I would expect your feelings in this regard to change. I put the conditional in there because interpreting them is much easier for some (and you can guess who they are - people with technical backgrounds) than others (poets, historians, social workers...)

Just today I was thinking about what it would be like to have an electric truck. lol! it would be terrible unless they start building chargers at boat ramps and in the mountains along trout streams.

Abetterrouteplanner will now let you enter the Rivian trucks as a vehicle type. I've done that and found a couple of things. First is that the CHAdeMO/CCS network is growing pretty fast and seems to be more reliable than it was even a year ago so that driving into the reasonably far boonies without access to the Tesla network shouldn't be that problematic. Second is that the RIvians can be charged from Tesla Destination chargers. They are found fairly frequently in fairly remote areas (hotels, motels, tourist attractions). Third Rivians (and Teslas) can be charged at campgrounds or marinas or at any garage that has an electric welder.

 

[T3slaOwner]

You certainly can rely on them but you have to know how to interpret them.

And that is the problem. Being able to analyze the state of the car and know what to expect from it requires a PhD. It used to be about "rocket science", now it will be about "electric vehicle science".

Tesla doesn't know what's acceptable to you. The median rate for the X seems to be about 0.3 mi/hr equivalent to a bit under 100 W or about 2.4 kWh/da. If you want the information collected by third party apps that poll the vehicle you will have to expect to pay that (I think most owners use at least one of these apps). 2.4 kWh costs me about $0.13/da. That's worth it to me.

You seem to be running down the same path as everyone else thinking the issue is about Wh or Wh/mi. The point is the car doesn't care what you think it's power usage should be under any given circumstance. As a recent Tesla owner said, "The car does what it wants". Bottom line is you can't know what to expect. Hence the rule, "always be charging, ABC".

That's not particularly good. The median for the X seems to be about 359 (the EPA rating is 316).

At 333 you should be able to go 200 miles on 68% of your battery. If you can't go that far with a 68% charge then you aren't getting 333 Wh/mi. The various odometers and energy displays are in your vehicle to tell you what is going on. Learn to interpret them and you will have few surprises. Of course they cannot predict an un forecast thunderstorm (takes my X's consumption from right around 300 to over 400) or headwind but will tell you what your charge status is going to be at destination shortly after you encounter them.

I can only work with the numbers the car reports to me. You seem to be focused on the Wh/mi consumption here. I'm not talking about the energy used going from point A to point B. I'm talking about using the car the way we are accustomed to using cars. I know my truck has 3/4 tank and I can drive a minimum of 300 miles without knowing if it will be raining or how long the truck sits parked or any of the other crap you need to factor into the spread sheet. "Learn to interpret them" is exactly the issue. People don't want to analyze spreadsheets to drive a car. Maybe Geeks do, but not the rest of us.

No, you don't. Rain and headwinds effect ICE vehicles in exactly the same way they effect electric vehicles. The difference is that you can pull into a gas station anywhere when petrol gets low and you cannot (as yet anyway) do that in a BEV.

It make be true that rain and headwinds affect all vehicles the same (or similar) but I've never needed to account for any of this when driving an ICE.

These factors you list aren't the real issue. The problem is there are far too many factors to ever get a handle on. You can't design a spreadsheet to tell me if I will need to charge on my next trip or how much I can drive locally without needing to charge to reach the Supercharger. It's all a nightmare with a Tesla. With an ICE it's easy to see just by looking at my fuel gauge... once... when I park the car.

Looking at the date you joined the forum it looks as if you have only had the car a month or so. When you learn how to read the displays, if you do, then I would expect your feelings in this regard to change. I put the conditional in there because interpreting them is much easier for some (and you can guess who they are - people with technical backgrounds) than others (poets, historians, social workers...)

See, more inaccurate assumptions. You really need to learn not to make assumptions based on far too little info. I've had my car over a year now.

Abetterrouteplanner will now let you enter the Rivian trucks as a vehicle type. I've done that and found a couple of things. First is that the CHAdeMO/CCS network is growing pretty fast and seems to be more reliable than it was even a year ago so that driving into the reasonably far boonies without access to the Tesla network shouldn't be that problematic. Second is that the RIvians can be charged from Tesla Destination chargers. They are found fairly frequently in fairly remote areas (hotels, motels, tourist attractions). Third Rivians (and Teslas) can be charged at campgrounds or marinas or at any garage that has an electric welder.

LOL! Yeah, in theory you can charge at electric welder facilities. But it's humorous to even be saying that.
I ran some numbers on the Rivian and took a look at the charging network for it. Yes, there are lots of chargers out there... well, lots of locations anyway. The vast majority of them are only 50 kW. That means for every three hours you drive your Rivian, you charge for two! Not much of a trip vehicle. With the max battery you can go perhaps 320 miles without pushing the boundaries too much. Then charge overnight... but not at a level 2 charger. 30 amps at 208 volts will take around 24 hours! No, not a trip vehicle at all.

 

[ajdelange]

And that is the problem. Being able to analyze the state of the car and know what to expect from it requires a PhD.

No, it does not. It requires some effort on the part of the user though.

You seem to be running down the same path as everyone else thinking the issue is about Wh or Wh/mi.

Of course I am because Wh/mi is the basis for the whole performance story. It is really the same as with ICE. A gallon of gas contains a certain amount of energy 50% of which will be lost as heat and the rest of which will be converted to traction. A Watt hour IS energy. Ten percent will be lost as heat and the rest will be converted to traction.
ICE: mpg; gas tank capacity
BEV:Wh/mi; battery capacity

The point is the car doesn't care what you think it's power usage should be under any given circumstance.

Of course it doesn't. It draws the Watt hours from the battery just as an ICE vehicle draws petrol from the gas tank according to its needs as determined by the conditions in which it is operated and the demands the driver makes of it.

Bottom line is you can't know what to expect. Hence the rule, "always be charging, ABC".

Bottom line is that unless you are mentally lazy it is very easy to know what to expect. Now there are some who have a mental block about anything involving a number or anything technical. In 50 years of marriage I have not been able to explain to my wife what a thermostat does nor, therefore, how to use it. I call these people "innumerate". If you are innumerate it would probably be best if you stuck to old tech, i.e. ICE vehicles until such time as you don't have to worry about what's in the battery any more than you have to worry about what's in the gas tank. For now, here's the rule: know your car; charge when convenient.

I know my truck has 3/4 tank and I can drive a minimum of 300 miles without knowing if it will be raining or how long the truck sits parked or any of the other crap you need to factor into the spread sheet.

Well you can't know that because rain increases your fuel consumption dramatically and so does a headwind and so does pulling a trailer. Thing is that when the low fuel warning comes on in an ICE vehicle you just pull into the nearest gas station and fuel up and so you never bothered to pay any attention to the way in which these factors effect your mpg.

"Learn to interpret them" is exactly the issue. People don't want to analyze spreadsheets to drive a car.

I know that if my battery is 3/4 full I can drive 225 miles. I know that if it rains heavily I'll get more like 175. I didn't use any spreadsheets to come up with those numbers. And I'm not hinting for nominations for the Fields Medal.

It make be true that rain and headwinds affect all vehicles the same (or similar) but I've never needed to account for any of this when driving an ICE.

You have had to account for them. You just didn't pay attention. When the fuel light came on at Exit 25 instead of Exit 30 you may have said "Hmm usually fill up at 30. Must not have left with a tank as full as I thought" if you paid any attention at all and pulled off at 25 to get gas.

These factors you list aren't the real issue.

There is no issue except in the minds of the few who basically shouldn't be driving EV's as the only joy they seem to derive from them is coming on fora like this one and whinging.

The problem is there are far too many factors to ever get a handle on. You can't design a spreadsheet to tell me if I will need to charge on my next trip or how much I can drive locally without needing to charge to reach the Supercharger.

The factors are all well understood by many and it is not necessary to design any spreadsheets as the Tesla's real time displays factor them all in and tell you, with astonishing accuracy, what you can expect at your next charging stop or destination.

It's all a nightmare with a Tesla.

Only to a minority. They should sell their cars.

With an ICE it's easy to see just by looking at my fuel gauge... once... when I park the car.

You delude yourself into thinking that you can do that but you can't for reasons I have given above. ICE vehicles are subject to the same physics as BEVs.

See, more inaccurate assumptions. You really need to learn not to make assumptions based on far too little info.

Clearly you are not familiar with Baysian inference.

LOL! Yeah, in theory you can charge at electric welder facilities. But it's humorous to even be saying that.

From a PlugShare description for Havre-Saint-Pierre, QC
"Un bon samaritain a laissé son adapteur 6-50 (première génération) pour Tesla au garage pour branchements futurs. Le branchement se fait sur la prise de la soudeuse. Merci! Malheureusement seulement branchement possible avec votre câble Tesla."

I ran some numbers on the Rivian and took a look at the charging network for it. Yes, there are lots of chargers out there... well, lots of locations anyway. The vast majority of them are only 50 kW. That means for every three hours you drive your Rivian, you charge for two! Not much of a trip vehicle. With the max battery you can go perhaps 320 miles without pushing the boundaries too much. Then charge overnight... but not at a level 2 charger. 30 amps at 208 volts will take around 24 hours! No, not a trip vehicle at all.

I come to the opposite conclusion but that's because I am looking for ways to make it work whereas you are looking for ways to make it NOT work. Sell your BEV(s). End your misery!

 

[jboy210]

Yeah but how much did plaintiffs' attorneys get?

1/3 of the total settlement pool plus expenses. Heck of a way to make money!

 

[T3slaOwner]

No, it does not. It requires some effort on the part of the user though.

Of course I am because Wh/mi is the basis for the whole performance story. It is really the same as with ICE. A gallon of gas contains a certain amount of energy 50% of which will be lost as heat and the rest of which will be converted to traction. A Watt hour IS energy. Ten percent will be lost as heat and the rest will be converted to traction.
ICE: mpg; gas tank capacity
BEV:Wh/mi; battery capacity


Of course it doesn't. It draws the Watt hours from the battery just as an ICE vehicle draws petrol from the gas tank according to its needs as determined by the conditions in which it is operated and the demands the driver makes of it.

Bottom line is that unless you are mentally lazy it is very easy to know what to expect. Now there are some who have a mental block about anything involving a number or anything technical. In 50 years of marriage I have not been able to explain to my wife what a thermostat does nor, therefore, how to use it. I call these people "innumerate". If you are innumerate it would probably be best if you stuck to old tech, i.e. ICE vehicles until such time as you don't have to worry about what's in the battery any more than you have to worry about what's in the gas tank. For now, here's the rule: know your car; charge when convenient.


Well you can't know that because rain increases your fuel consumption dramatically and so does a headwind and so does pulling a trailer. Thing is that when the low fuel warning comes on in an ICE vehicle you just pull into the nearest gas station and fuel up and so you never bothered to pay any attention to the way in which these factors effect your mpg.

I know that if my battery is 3/4 full I can drive 225 miles. I know that if it rains heavily I'll get more like 175. I didn't use any spreadsheets to come up with those numbers. And I'm not hinting for nominations for the Fields Medal.


You have had to account for them. You just didn't pay attention. When the fuel light came on at Exit 25 instead of Exit 30 you may have said "Hmm usually fill up at 30. Must not have left with a tank as full as I thought" if you paid any attention at all and pulled off at 25 to get gas.


There is no issue except in the minds of the few who basically shouldn't be driving EV's as the only joy they seem to derive from them is coming on fora like this one and whinging.


The factors are all well understood by many and it is not necessary to design any spreadsheets as the Tesla's real time displays factor them all in and tell you, with astonishing accuracy, what you can expect at your next charging stop or destination.




Only to a minority. They should sell their cars.


You delude yourself into thinking that you can do that but you can't for reasons I have given above. ICE vehicles are subject to the same physics as BEVs.





Clearly you are not familiar with Baysian inference.




From a PlugShare description for Havre-Saint-Pierre, QC
"Un bon samaritain a laissé son adapteur 6-50 (première génération) pour Tesla au garage pour branchements futurs. Le branchement se fait sur la prise de la soudeuse. Merci! Malheureusement seulement branchement possible avec votre câble Tesla."




I come to the opposite conclusion but that's because I am looking for ways to make it work whereas you are looking for ways to make it NOT work. Sell your BEV(s). End your misery!

LOL I'm tried of trying to reason with you. My experience is that I can know at any time that my truck will give me between 400 and 450 miles to a tank. So I never have to focus on when and where I will fuel. I just look at the gauge and know how far I can go, even if I've looked at it last a week ago. The Tesla does not get nearly as consistent mileage even though my trips are very consistent. Talking about rain impacting my truck mileage is pure BS. I drove the same pickup for 20 years and never got more than 10% variation in range. NEVER. There are times when I find I need to refuel the Tesla before I've gone 200 miles.

Facts are facts. Trying to talk about Wh/mi is pointless when there are OTHER drains on the battery which do not show up in those numbers reported by the car. Then there is the aberrant Wh/mi seen at various times like the initial portion of any trip which YOU yourself have talked about and tried to understand.

Teslas are erratic in their energy use if you don't fit the standard norm of driving every day in the same way. They are simply affected much more and by a larger number of variables.

 

[ajdelange]

Probably best.

LOL I'm tried of trying to reason with you. .... Talking about rain impacting my truck mileage is pure BS.

Probably best. The juxtaposition of phrases like this suggest that perhaps reasoning through the laws of the physics as applied to automobiles may not be where your strengths lie. But ask yourself: If rain reduces the range of a Tesla which runs on four wheels on the ground why would it NOT so effect a truck which runs on four wheels in contact with the ground?

Facts are facts. Trying to talk about Wh/mi is pointless when there are OTHER drains on the battery which do not show up in those numbers reported by the car.

Yes facts are facts. The fact is that there are no drains on the battery that are not reported by the car. Can you suggest which loads are NOT reported by the car?

OTE="T3slaOwner, post: 3985853, member: 111104"]Then there is the aberrant Wh/mi seen at various times like the initial portion of any trip which YOU yourself have talked about and tried to understand. [/QUOTE] Yes, I have struggled to understand that. I still don't know the answer but after observing it for months have concluded that it must be caused by sampling as was suggested by someone back when you were posting using the other name and location.

They are simply affected much more and by a larger number of variables.

Do you have any idea how ridiculous that sounds to an engineer?

 

[T3slaOwner]

Probably best.

Probably best. The juxtaposition of phrases like this suggest that perhaps reasoning through the laws of the physics as applied to automobiles may not be where your strengths lie. But ask yourself: If rain reduces the range of a Tesla which runs on four wheels on the ground why would it NOT so effect a truck which runs on four wheels in contact with the ground?

Measurements. I don't sit in an armchair and try to figure things out without verifying they are valid. I've already given you the data, you choose to ignore it.

Yes facts are facts. The fact is that there are no drains on the battery that are not reported by the car. Can you suggest which loads are NOT reported by the car?

When you say "reported" that is vague. The vampire drain is not actually reported. You simply see the charge disappear from your battery. The rate is not documented. You just have to wait and see how much it is when it happens.

OTE="T3slaOwner, post: 3985853, member: 111104"]Then there is the aberrant Wh/mi seen at various times like the initial portion of any trip which YOU yourself have talked about and tried to understand.

Yes, I have struggled to understand that. I still don't know the answer but after observing it for months have concluded that it must be caused by sampling as was suggested by someone back when you were posting using the other name and location.

Do you have any idea how ridiculous that sounds to an engineer?

There is the problem. You think like an engineer while the rest of us are car owners. It is exactly when engineers make decisions affecting users that we end up with hard to use products and unhappy customers. And yes, I do know how ridiculous it sounds for an engineer to talk about knowing everything about the power use of a car and then acknowledge they don't know what is happening with a power drain.

 

[ajdelange]

The vampire drain is not actually reported.

9/4 - 10:36, 8.5700, 11.8491, 0.7233, 5319.1
9/2 - 14:39, 4.7900, 50.3984, 0.0950, 5248.4
8/31 - 10:45, 9.1500, 18.1887, 0.5031, 5238.0
8/30 - 14:38, 1.2800, 22.7585, 0.0562, 5220.5
8/29 - 11:37, 0.6300, 0.9106, 0.6919, 5207.8
8/29 - 09:15, 1.5800, 13.5807, 0.1163, 5193.9
8/28 - 09:08, 3.7700, 18.3884, 0.2050, 5136.9
8/27 - 10:07, 11.1300, 64.0098, 0.1739, 5118.5
8/23 - 11:15, 7.6200, 19.6272, 0.3882, 4988.0
8/20 - 23:35, 0.3200, 1.2490, 0.2562, 4936.8
8/20 - 09:15, 1.6100, 18.4495, 0.0873, 4713.8
8/19 - 09:13, 6.9800, 43.4572, 0.1606, 4690.0
8/16 - 23:43, 0.6400, 1.5503, 0.4128, 4662.6
8/16 - 19:55, 0.9600, 1.1661, 0.8232, 4649.8
8/16 - 16:55, 1.2600, 1.7924, 0.7030, 4638.5[/hr]

Dates, Phantom Drain [mi], Drain Duration

---

 

[T3slaOwner]

9/4 - 10:36, 8.5700, 11.8491, 0.7233, 5319.1
9/2 - 14:39, 4.7900, 50.3984, 0.0950, 5248.4
8/31 - 10:45, 9.1500, 18.1887, 0.5031, 5238.0
8/30 - 14:38, 1.2800, 22.7585, 0.0562, 5220.5
8/29 - 11:37, 0.6300, 0.9106, 0.6919, 5207.8
8/29 - 09:15, 1.5800, 13.5807, 0.1163, 5193.9
8/28 - 09:08, 3.7700, 18.3884, 0.2050, 5136.9
8/27 - 10:07, 11.1300, 64.0098, 0.1739, 5118.5
8/23 - 11:15, 7.6200, 19.6272, 0.3882, 4988.0
8/20 - 23:35, 0.3200, 1.2490, 0.2562, 4936.8
8/20 - 09:15, 1.6100, 18.4495, 0.0873, 4713.8
8/19 - 09:13, 6.9800, 43.4572, 0.1606, 4690.0
8/16 - 23:43, 0.6400, 1.5503, 0.4128, 4662.6
8/16 - 19:55, 0.9600, 1.1661, 0.8232, 4649.8
8/16 - 16:55, 1.2600, 1.7924, 0.7030, 4638.5[/hr]

Dates, Phantom Drain [mi], Drain Duration

---

I've never seen this data from my car. Where does it come from? Which display and how do you get it into your computer?

 

[ajdelange]

The API. You get it through a third party app. I used Stats. It can forward the data in several ways for example e-mali.

 

[T3slaOwner]

The API. You get it through a third party app. I used Stats. It can forward the data in several ways for example e-mali.

Do the columns have labels? I meant to take a photo today, but forgot. I don't think i even got 160 miles out of a 90% charge run down to 18%. The only screen that shows the important data is the charging display along with the trip as backdrop, but only if you get it before you disconnect the charging session or something like that. I had to hurry a bit to avoid idle fees and by the time I remembered to take a photo the info was gone.

That's why I say it is such a PITA to try to keep track of this car. My truck is so easy. The only thing I need to worry about is resetting the trip odometer and saving the gas receipt with the miles written down. The mileage is not great, but driving in the rain doesn't make it drop or pretty much anything else other than stop and go traffic or driving fast which I usually don't do.

But it is very clear there is a large energy loss that is not reported in any of the car displays. I thought it might be explained by the battery capacity dropping, but that is easy to check when charging. Increase in reported charge state vs. kWh reported going into the battery. That only shows about a 4% loss of capacity - normal for the first 25,000 miles. So there is energy lost somewhere. The irony is that the reported mileage is improving. Today on a 65 mph highway I was seeing 285 Wh/mi over the last 30 miles. I think it was even down to 280 at times. Terrain was relatively level, Rt 95 south of Washington DC. And that was with range mode OFF.

 

[Rocky_H]

That's why I say it is such a PITA to try to keep track of this car. My truck is so easy. The only thing I need to worry about is resetting the trip odometer and saving the gas receipt with the miles written down. The mileage is not great, but driving in the rain doesn't make it drop or pretty much anything else other than stop and go traffic or driving fast which I usually don't do.

I see why this is confusing you. You think the Tesla is doing something wrong without understanding what the fundamental difference is.

With a gasoline engine, your truck is literally wasting about two thirds of the energy of the gasoline. It is constantly dumping huge amounts of energy out the tailpipe and radiator in a desperate attempt to keep the engine from melting itself down with ungodly amounts of excess waste heat because gasoline combustion engines are so horribly inefficient.

So would you notice a bit extra wind resistance or rain resistance? No--probably not. An extra loss of some kind is going to be a very small % change compared to the huge losses the vehicle is already constantly having, so you won't notice that extra half a mpg difference in your efficiency.

Electric motors, however, are about 90% efficient in their energy use. Any system that is very highly efficient is going to show noticeable movement with any extra fixed losses. So sure, some of these extra factors do show up a little bit with an electric vehicle, where they aren't very obvious blended in with the large losses of gas vehicles. There are some people (like yourself) who get upset about this, but it's the nature of a drive train that innately has very low losses. That's the pro/con of comparing these. EV you get the benefits of great efficiency but see the conditions changing it. With gas cars, you always get terrible efficiency, but get to be blissfully unaware of conditions having any effect.

 

[T3slaOwner]

I see why this is confusing you. You think the Tesla is doing something wrong without understanding what the fundamental difference is.

With a gasoline engine, your truck is literally wasting about two thirds of the energy of the gasoline. It is constantly dumping huge amounts of energy out the tailpipe and radiator in a desperate attempt to keep the engine from melting itself down with ungodly amounts of excess waste heat because gasoline combustion engines are so horribly inefficient.

How is that in any way relevant???

So would you notice a bit extra wind resistance or rain resistance? No--probably not. An extra loss of some kind is going to be a very small % change compared to the huge losses the vehicle is already constantly having, so you won't notice that extra half a mpg difference in your efficiency.

Again, not at all relevant. If you think this somehow explains the lack of consistency in an EV you need to go back to fundamentals and learn about efficiency and how it is calculated. Try running some numbers that result in mpg or Wh/mi and you will see what I mean.

Electric motors, however, are about 90% efficient in their energy use. Any system that is very highly efficient is going to show noticeable movement with any extra fixed losses. So sure, some of these extra factors do show up a little bit with an electric vehicle, where they aren't very obvious blended in with the large losses of gas vehicles. There are some people (like yourself) who get upset about this, but it's the nature of a drive train that innately has very low losses. That's the pro/con of comparing these. EV you get the benefits of great efficiency but see the conditions changing it. With gas cars, you always get terrible efficiency, but get to be blissfully unaware of conditions having any effect.

The issue is not in any way, shape or form about the efficiency of an electric motor. It is the fact that the Teslas don't keep tabs on where all the "money" goes. In theory the Wh/mi rating tracks all usage of electricity while you are driving, but my personal experience is that the numbers don't add up when you check to see how many miles you can travel between charges in routine use. They also don't give you any access to the *many* numbers other than the brief moment when they appear on the screen. I guess I need to look into an app to see what the deal is with my car.

I wish I had taken the picture of the last charge. As I've already posted, my Wh/mi have been very good lately, the same with or without range mode enabled. Yet I only got around 160 miles on 72% of a 100 kWh battery. Actually, the photo from when the charging started shows this well enough.

X_trip_190911_sm

• T3slaOwner
• Sep 12, 2019

Started at 90% charge

Started at 90% on Monday late PM, run down to 18% by Tuesday early PM, so 72%. I did use Sentry mode overnight with a drop of 6% so now 66%. With 4% loss of range that's 96 kWh * 66% = 63 kWh. So 7 kWh unaccounted for.

None of this has anything to do with the efficiency of the electric motor vs. an ICE. The weather is warm so the battery should be at peak efficiency. Where do the kWh go?

There are many, many other inconsistencies in the behavior of the car. The navigator is another one. Sometimes it will route me to my destination, which is at least 10% away from any Superchargers, without suggesting a charging stop with a projected range of 7% at destination. This time it recommended I stop with 18% on the battery which would have left me with 9%. Why one and not the other?

I guess I get frustrated because I can't recommend this car to many people. Most want a car that is easy to drive. Combine all the quirks of the car with all the issues trying to get service and this is a car that no one should buy.

 

[Rocky_H]

How is that in any way relevant???

Because of this:

I know my truck has 3/4 tank and I can drive a minimum of 300 miles without knowing if it will be raining or how long the truck sits parked or any of the other crap you need to factor into the spread sheet.

And this:

It make be true that rain and headwinds affect all vehicles the same (or similar) but I've never needed to account for any of this when driving an ICE.

And this:

With an ICE it's easy to see just by looking at my fuel gauge... once... when I park the car.

And this:

Talking about rain impacting my truck mileage is pure BS. I drove the same pickup for 20 years and never got more than 10% variation in range. NEVER. There are times when I find I need to refuel the Tesla before I've gone 200 miles.

And this:

My truck is so easy. The only thing I need to worry about is resetting the trip odometer and saving the gas receipt with the miles written down. The mileage is not great, but driving in the rain doesn't make it drop or pretty much anything else

You were still going on and on about how your truck was not affected by any of these things. It most certainly was, but the truck did not display this to let you see it.

The issue is not in any way, shape or form about the efficiency of an electric motor. It is the fact that the Teslas don't keep tabs on where all the "money" goes.

It IS in any way shape or form about the efficiency of an electric motor, or more specifically, contrasted with how terrible the efficiency of gas engines are. This is what I have been trying to explain to you. These impacts like rain and headwinds absolutely do impact your gas truck, but you have never been able to see that before, because it gets completely lost in the constant large inefficiencies, and now they are shocking to you when you get to see that effect in a different kind of vehicle. But you are also a little correct that there is a second part to it. There is some idle drain that draws energy away that isn't used for driving, and there is some extra energy use from battery heating that happens at the very start when it's cold that is sometimes captured in the displayed efficiency numbers, but sometimes isn't that easy to see.

Again, your truck hides these things. The idle draw from computers and such is fairly low, but is drawing down the 12V battery in your truck. And then when you start and run your truck, the engine has some extra load on it, sucking efficiency by driving the alternator to refill the electrical energy losses from the idle drain of running those computers. Again, you had never seen that before, because running the alternator is just yet another drag on the engine that is not noticeable with the massive inefficiencies the engine already has.

That is the other aspect that catches people off guard, who are new to electric vehicles. You are used to thinking how the gasoline translates only and directly to the driving distance, which isn't exactly true, but it appeared that way. Electrical use becomes kind of transparent in that, because it draws from your 12V battery overnight, and you never really get to "see" the gasoline that is depleted to refill that back up. In an electric vehicle, it's the main battery that is your one pool for moving the car and supplying the electrical load, so it's the heat + idle drain + miles + etc. and the extra finely detailed information lets you see that, which is a little surprise at first.

 

[T3slaOwner]

Because of this:

And this:

And this:

And this:

And this:


You were still going on and on about how your truck was not affected by any of these things. It most certainly was, but the truck did not display this to let you see it.

Which says nothing of why the inefficiencies of an ICE are relevant. Efficiencies are multiplicative, not additive. Does that mean anything to you?

It IS in any way shape or form about the efficiency of an electric motor, or more specifically, contrasted with how terrible the efficiency of gas engines are. This is what I have been trying to explain to you. These impacts like rain and headwinds absolutely do impact your gas truck, but you have never been able to see that before, because it gets completely lost in the constant large inefficiencies, and now they are shocking to you when you get to see that effect in a different kind of vehicle. But you are also a little correct that there is a second part to it. There is some idle drain that draws energy away that isn't used for driving, and there is some extra energy use from battery heating that happens at the very start when it's cold that is sometimes captured in the displayed efficiency numbers, but sometimes isn't that easy to see.

I can't explain this to you further without using math. Math is an essential feature in understanding many things in physics and mechanics. Did you understand what I wrote above? If not, we need to teach you some math.

Again, your truck hides these things. The idle draw from computers and such is fairly low, but is drawing down the 12V battery in your truck. And then when you start and run your truck, the engine has some extra load on it, sucking efficiency by driving the alternator to refill the electrical energy losses from the idle drain of running those computers. Again, you had never seen that before, because running the alternator is just yet another drag on the engine that is not noticeable with the massive inefficiencies the engine already has.

Which is all factored into the mileage calculation in my truck. You keep talking about mixing inefficiencies but that is irrelevant. In the Tesla vampire drain is not factored in and is virtually unknown and unpredictable. Or maybe it's not vampire drain. Maybe some other aspect of the car's accounting is off. I don't know. I just know the kWh don't add up.

That is the other aspect that catches people off guard, who are new to electric vehicles. You are used to thinking how the gasoline translates only and directly to the driving distance, which isn't exactly true, but it appeared that way. Electrical use becomes kind of transparent in that, because it draws from your 12V battery overnight, and you never really get to "see" the gasoline that is depleted to refill that back up. In an electric vehicle, it's the main battery that is your one pool for moving the car and supplying the electrical load, so it's the heat + idle drain + miles + etc. and the extra finely detailed information lets you see that, which is a little surprise at first.

Which is essentially arm waving. The bottom line is knowing what to expect from the car. I don't have the luxury of plugging my Tesla in to charge every night so I can ignore the energy usage. That is what most people do with their ICE. They just fill the tank when it's low. That paradigm doesn't work so well when you aren't at home every night since filling stations are much, MUCH, MUCH fewer and further between. We celebrate the opening of a new filling station for Teslas. So it is very, VERY, VERY important to be able to plan usage when not able to charge every night.

 

[ajdelange]

The following simple example should clarify the efficiency masking question. In it I've used a traction load of 30 kW. This would include drag, rolling resistance, bearing resistance etc. Assume the vehicle is at cruise speed on a level surface i.e. make the problem as simple as possible. I've also assumed that rain increases the traction load by 1/3 (which is what I seem to observe most of the time). To makes things a little more interesting I have assumed that cabin heat is on at 3 kW. This costs nothing in terms of "fuel" in the ICE but does, of course, in the BEV.

The numbers make it clear that where the traction load is the major load "fuel" flow scales pretty closely with the traction load. This is because the heat losses (2nd law or inverter/motor) increase in the same proportion as the traction load.

No Rain
ICE Power Required for Traction: 30 kW
ICE Power Lost to Heat: 45 kW
ICE Additional Power for 3 kW Cabin A/C: 0 kW
ICE Total Power Required: 75 kW

Rain
ICE Power Required for Traction: 40 kW
ICE Power Lost to Heat: 60 kW
ICE Additional Power for 3 kW Cabin A/C: 0 kW
ICE Total Power: 100 kW
ICE Fuel40/Fuel30 = 133%

No Rain
BEV Power required for Traction: 30 kW
BEV Power Lost to Heat: 3.3 kW
BEV Additional Power for 3 kW Cabin A/C: 3 kW
BEV Total Power Required: 36.3 kW

Rain
BEV Power required for Traction: 40 kW
BEV Power Lost to Heat: 4.4 kW
BEV Additional Power for 3 kW Cabin A/C: 3 kW
BEV Total Power Required: 47.4 kW
BEV Fuel40/Fuel30 = 131%

Thus it appears that the less efficient ICE vehicle does not mask additional traction loading (the wind and the rain). Loads that demand extra fuel suppress the relative effect of increased traction load. In a BEV this is any load (A/C, heat, sound system, headlights....). In an ICE vehicle cabin heat is excepted (but the fan power is not).

 

[alphainfinity]

This whole thread comes down to basically one basic thing.....we need more superchargers and charging an EV needs to take less time.

Tesla is improvements but there is still quite anxiety.

 

[ajdelange]

This whole thread comes down to basically one basic thing.....we need more superchargers and charging an EV needs to take less time.

This reminds me of the sign over the counter in Bessler's photo shop in Hermosa Beach many years back (when they had photo shops). It said "Es is besser reich und gesund zu sein als arrme und krank." which translates to "It is better to be rich and healthy than poor and sick". And the say the British are the masters of understatement.

In any case the OP was concerned about apparent precipitous loss in battery capacity in a new car. More and faster super chargers would be little comfort to someone with a potential defective battery problem in a new, very expensive car. The thrust of the thread is that battery state is inherently difficult to measure accurately and that, therefore, one should not panic over a couple of startling battery readings but should, rather, look at battery history over some period of time before drawing the conclusions that the battery pack is defective. Knowledgeable posters indicated that some decline is to be expected early on the rate of which should decrease after 10,000 miles or so.

OP's observed spread of 4.7% is eye catching for sure and I would certainly have taken note of it. In my case the spread over 9 months has been less than half that. If that scatter turns into a trend over a few thousand miles then there is a problem.

 

[alphainfinity]

Once again, if we had more superchargers and a faster charging rate, I don’t think people would be upset over a 4% drop in capacity.

My iPhone battery doesn’t have as much capacity as the day I purchased it. Do you know why I don’t care? My phone still lasts all day and fast charging opportunities are frequent and plentiful.

 

[ElectricOrgan]

Once again, if we had more superchargers and a faster charging rate, I don’t think people would be upset over a 4% drop in capacity.

My iPhone battery doesn’t have as much capacity as the day I purchased it. Do you know why I don’t care? My phone still lasts all day and fast charging opportunities are frequent and plentiful.

I'm not sure I understand. What 4% are you talking about? Is it the 4% many Tesla owners experience in the first year or two of ownership? There have been a lot of numbers tossed around in this thread.