First time user of ABRP - trip planning question

[Phlier]

Right, it's a measure of the amount of ENERGY in your battery. It's not a unit of distance.

I think that's the point that guys need to get absorbed into their brain in order to understand the rest of the discussion. The entire explanation is based on guys getting that point straight.

You got me convinced, btw. I switched over to miles the other day after reading this thread. And as you stated, you can always see percentage on the energy graph trip page.

The problem is, this thread has gotten me so interested in the whole battery thing that now I'm thinking of springing for the subscription fee to TeslaFi. Thanks... just what I need.. yet *another* monthly subscription fee. The whole software and internet services industry has switched over to this "pay us our monthly dues" subscription crap, and I'm really getting tired of it. But I digress...

 

[M3BlueGeorgia]

I think that's the point that guys need to get absorbed into their brain in order to understand the rest of the discussion. The entire explanation is based on guys getting that point straight.

You got me convinced, btw. I switched over to miles the other day after reading this thread. And as you stated, you can always see percentage on the energy graph trip page.

The problem is, this thread has gotten me so interested in the whole battery thing that now I'm thinking of springing for the subscription fee to TeslaFi. Thanks... just what I need.. yet *another* monthly subscription fee. The whole software and internet services industry has switched over to this "pay us our monthly dues" subscription crap, and I'm really getting tired of it. But I digress...

See how you feel about showing EPA miles in Utah in the middle of winter.
For example if you are 60 miles from home, its 15F outside and the car tells you you have 90 miles of EPA range left, you are probably not going to make it home without stopping to charge.

I get that people like to look at miles of range. The problem is the miles being provided are only really useful if your driving habits roughly approximate to the EPA test suite, as mine do most of the time in Georgia and Florida in warm and hot weather, so people can be tricked by it.

Regardless, Tesla allow you to configure which you want to display. And if you have several drivers each can make a different choice.

So by all means show EPA miles (or km). All I ask is you understand that it isn't the car giving you a forecast of how long you can travel, just a way of measuring level of charge.
It'd be nice if Tesla offered a 3rd option, to show the kWhs of charge left in the battery. I'd rather have that than percent or EPA range.

 

[acarney]

See how you feel about showing EPA miles in Utah in the middle of winter.
For example if you are 60 miles from home, its 15F outside and the car tells you you have 90 miles of EPA range left, you are probably not going to make it home without stopping to charge.

I get that people like to look at miles of range. The problem is the miles being provided are only really useful if your driving habits roughly approximate to the EPA test suite, as mine do most of the time in Georgia and Florida in warm and hot weather, so people can be tricked by it.

Regardless, Tesla allow you to configure which you want to display. And if you have several drivers each can make a different choice.

So by all means show EPA miles (or km). All I ask is you understand that it isn't the car giving you a forecast of how long you can travel, just a way of measuring level of charge.
It'd be nice if Tesla offered a 3rd option, to show the kWhs of charge left in the battery. I'd rather have that than percent or EPA range.

The kWh would be HUGELY useful. Then a “real time” (maybe averaged over 30 seconds) kW usage and watt/mile like it already displays. Then I could see that when I’m driving 30mph I use x amount and when I turn the heater on I use y amount. Can I afford to run the heater for awhile or not. Would really help for me to predict what I’m getting myself into compared to right now “well I know it uses a lot more... like 20-50% more...”

 

[Rocky_H]

See how you feel about showing EPA miles in Utah in the middle of winter.
For example if you are 60 miles from home, its 15F outside and the car tells you you have 90 miles of EPA range left, you are probably not going to make it home without stopping to charge.

You are doing this projecting thing again, where you think people are treating that 90 rated miles on the display as if it is engraved by God's own hand on a stone tablet coming down from the mountain, and that will mean 90 real distance miles regardless of any conditions or speed or anything. Hopefully most people aren't that clueless. And you're also doing this thing that I see people do, where the sentence starts off, "What if you find yourself..." No. Teleporting doesn't exist. People don't just appear out of thin air sitting in a car on the highway, moving at speed. They came from somewhere, and they have been driving for a while to get there. So during that time, when they suddenly "find themselves" at 60 miles left to go, they have been keeping an eye on the remaining margin in the Navigation or Energy app. And if the 90 over 60 was going to be a problem, they should have been slowing a bit before this point so they aren't showing like a 2% remaining estimate.

 

[eustachio]

Haven't read all the posts, but:
I like percent better, I obsess less about range than when I display miles, it's probably irrational, but there you go.

And you can see projected miles in the energy graph if desired.

 

[darth_vad3r]

See how you feel about showing EPA miles in Utah in the middle of winter.
For example if you are 60 miles from home, its 15F outside and the car tells you you have 90 miles of EPA range left, you are probably not going to make it home without stopping to charge.

I get that people like to look at miles of range. The problem is the miles being provided are only really useful if your driving habits roughly approximate to the EPA test suite, as mine do most of the time in Georgia and Florida in warm and hot weather, so people can be tricked by it.

Regardless, Tesla allow you to configure which you want to display. And if you have several drivers each can make a different choice.

So by all means show EPA miles (or km). All I ask is you understand that it isn't the car giving you a forecast of how long you can travel, just a way of measuring level of charge.
It'd be nice if Tesla offered a 3rd option, to show the kWhs of charge left in the battery. I'd rather have that than percent or EPA range.

I totally do not think of the number next to the battery as a distance. I think of it as a number that tells me what level my battery is at. That's how you think of %, right. Your units go from 0 to 100. Mine go from 0 to 386. They are both just scales from 0 to 'max'.

I like my scale because "270" one day means the same thing as "270" the next day. Meanwhile "70" on the other scale can be different every day.

Nobody should use the numbers next to the battery gauge to decide if they're actually going to arrive somewhere without the battery dying or getting "too low". We have the trip nav estimator for that, and that does show % ... so it's actually a bit redundant to see the current percent next to the battery icon and on the trip nav at the same time.

If you ever got the impression that I thought the "miles" will guide you into have far you can drive, I misspoke, miswrote, or wasn't clear enough. I mean, it's a ROUGH estimator. If it's summer and I need to drive "100" and the battery says "150" I can probably make it. But I'm actually going to punch it into the nav anyways to really find out what it thinks. I wish the nav would estimate my km remaining as well as just %.

 

[darth_vad3r]

Haven't read all the posts, but:
I like percent better, I obsess less about range than when I display miles, it's probably irrational, but there you go.

And you can see projected miles in the energy graph if desired.

That's a great reason to recognize your own behaviour and prevent yourself some obsession.

Just check up on the battery health like @M3BlueGeorgia mentioned above once in a while by switching to distance for a charge to your favourite X% charge limit target.

For people who prefer % but do want to obsess, I would suggest doing this as frequently as every time your charge hits the X% target you've set it to, then you can see if your battery's doing something funky at least once in a while.

You can actually set your Easy Entry profile to show distance, then when you charge, you'll be in distance, and the notification that says you are done charging will tell you what distance it stopped at, instead of %.

When you get in you'll briefly see distance before your seat adjusts to your profile.

 

[darth_vad3r]

The kWh would be HUGELY useful. Then a “real time” (maybe averaged over 30 seconds) kW usage and watt/mile like it already displays. Then I could see that when I’m driving 30mph I use x amount and when I turn the heater on I use y amount. Can I afford to run the heater for awhile or not. Would really help for me to predict what I’m getting myself into compared to right now “well I know it uses a lot more... like 20-50% more...”

I think it would be VERY interesting, but I actually don't think it's as useful as rated miles. 25 kWh in my car might get me farther than 25 kWh in your car, but 100 rated miles in my car should get me about the same distance as it would get you in your car, even if we have different trims (and no I don't think it would get us 100 miles!).

I would also find VERY interesting a chart averaging our kW in 'real time' averaged over 30 seconds. Or maybe that's what you meant.

In any case, both kW and kWh would be interesting to see.

 

[darth_vad3r]

I get your point.

My solution is to occasionally briefly flip the display to distance when the car has just charged to 90% to see how things are going with the battery (and extrapolate to 100%). Currently after 27K miles (43km) I'm at about 304 instead of 310, so that's pretty good.
Then flip back to percent before driving. I probably do that every month or so.

I also flip to % once in a while, but usually I just bring up the energy trip chart and can see the current % on the little indicator that traces along the prediction line. I use nav even when I'm going to work or somewhere I know, just in case it reroutes me for traffic, and so I can see what it predicts I will arrive and roundtrip at.

As I also mentioned above, for people who are interested in flipping often, you can set your Easy Entry profile to the opposite distance/percent. At least I know this works for different named profiles ... I haven't actually tested it with Easy Entry. Maybe that one is treated "special"?

 

[Phlier]

See how you feel about showing EPA miles in Utah in the middle of winter.
For example if you are 60 miles from home, its 15F outside and the car tells you you have 90 miles of EPA range left, you are probably not going to make it home without stopping to charge.

I get that people like to look at miles of range. The problem is the miles being provided are only really useful if your driving habits roughly approximate to the EPA test suite, as mine do most of the time in Georgia and Florida in warm and hot weather, so people can be tricked by it.

Regardless, Tesla allow you to configure which you want to display. And if you have several drivers each can make a different choice.

So by all means show EPA miles (or km). All I ask is you understand that it isn't the car giving you a forecast of how long you can travel, just a way of measuring level of charge.
It'd be nice if Tesla offered a 3rd option, to show the kWhs of charge left in the battery. I'd rather have that than percent or EPA range.

Your point is well taken, but I think since I now have a better education about the battery than I thought I ever would have after reading this thread, I'll be keeping a very close eye on how both values correlate to each other over time. And I'll be keeping a close eye out for any pixies and their horrible, battery depleting blue bricks! LoL, for ever more, I will think of our evil Sith friend @darth_vad3r every time I see any battery degradation on my chart, and think that more blue bricks just got glued to the sides of my battery's swimming pool. Damn those pixies!

I may be in Utah, but luckily I don't have to go through typical Utah winters in our town; we're in St. George, which stays within 5F of Las Vegas year 'round. So hot, horrible summers, followed by eight months of bliss. The fall, winter, and spring seasons here are so amazing that it makes living in a furnace for four months worth it.

We are a very popular "snow bird" destination city for those seeking out warmer climes during the winter. St. George is beautiful red rock desert.

 

[edigest]

Hate to resurrect this since someone is so obsessed (and kindof nasty if others have a different opinion).

LOL. Everything in the car is an estimate in one way or another. Estimates fluctuate based on inputs, including temperature.

Gee, miles is an estimate, too?!?

Here's where you lose me:

Percentage is a representation of that estimate (kWh), divided by a SECOND estimate (kWh) of the total current maximum capacity of the battery (which may be less than day 1 because of degradation or other factors).

Feel free to school me if you wrote the code, but ...

I don't think you have any insight into what values actually go into percentage. It is just as likely that percentage is calculated from the actual energy contained in the battery at any given moment (vice a "representation of [an] estimate [of] (kWh)").

Your supposition of how percentage is calculated is interesting. I can just as easily say miles is a representation of an estimate of the range of a unit of energy applied to a percentage [that] is a representation of that estimate (kWh), divided by a SECOND estimate (kWh) of the total current maximum capacity of the battery (which may be less than day 1 because of degradation or other factors).

In other words, miles is calculated based on the current percent of charge.

That would make miles only as accurate as the estimate of range per unit of energy combined with the percentage it is based on. Again, if you actually wrote the code and know that isn't how miles is calculated, do tell.

 

[darth_vad3r]

Hate to resurrect this since someone is so obsessed (and kindof nasty if others have a different opinion).



Gee, miles is an estimate, too?!?

Here's where you lose me:



Feel free to school me if you wrote the code, but ...

I don't think you have any insight into what values actually go into percentage. It is just as likely that percentage is calculated from the actual energy contained in the battery at any given moment (vice a "representation of [an] estimate [of] (kWh)").

Your supposition of how percentage is calculated is interesting. I can just as easily say miles is a representation of an estimate of the range of a unit of energy applied to a percentage [that] is a representation of that estimate (kWh), divided by a SECOND estimate (kWh) of the total current maximum capacity of the battery (which may be less than day 1 because of degradation or other factors).

In other words, miles is calculated based on the current percent of charge.

That would make miles only as accurate as the estimate of range per unit of energy combined with the percentage it is based on. Again, if you actually wrote the code and know that isn't how miles is calculated, do tell.

I didn't write the code, no, but I have read code that retrieves voltage values from the CAN bus, so I'll feel free to school you again anyways.

I'm not nasty, and this isn't an opinion. Preferring percent over miles is an opinion. You are entiteld to your opinion.

Believing that dashboard percent tells you more about the amount of energy in your battery than dashboard miles is just flat out wrong.

A degraded battery still charges to "100%".

The "current percentage of charge" is not what "dashboard percent" is telling you. There are many threads on this and other forums describing values available from CAN bus monitoring, including individual brick voltages, energy amounts, percentage amounts, etc.

Percent is a measure of "fullness" based on voltage. It is like the depth of your cup. Your cup is half full. My cup is half full. They are both at 50%. You can't fill any cup past the brim, that's 100%.

Which one has more water? You don't know. You need to know how tall the cup is, and how wide the cup is.

Degradation changes the dimensions of your cup ... % will tell you that you are "half way", but "miles" will tell you how much water is in the cup. % is lines on the side of the cup, miles is a measure of actual fluid ounces held in the cup. You can tell they are equivalent on a new measuring cup ... but once sludge starts to build up on the sides of the measuring cup, they aren't equivalent any more.

I don't know how many more ways I can say the same thing.

You are SUPPOSING that I am supposing, but I'm basing my explanation on the backs of many other people who have tinkered with the API and CAN bus, and unveiled much information "under the hood" not visible to us mere mortals simply looking at the dashboard.

 

[darth_vad3r]

I can do this all year. Bring on the disagrees.

Here, on the part where I apparently lost you:

"Percentage is a representation of that estimate (kWh), divided by a SECOND estimate (kWh) of the total current maximum capacity of the battery (which may be less than day 1 because of degradation or other factors)."

C = how much water your cup could hold theoretically new from the factory.
Estimate B = how much total water your cup can hold today (this can change based on sludge building up on the walls of your cup)
Estimate A = how much water is currently in your cup (say 4 ounces)

B = C on day one (in most cases). Say 16 gallons

Dashboard % = A/B (which on day one is the exact same as A/C). 4/16 = 25%

On day 2000, when the B estimate has gone down due to calibration, degradation, etc. A/B no longer equals A/C. Your old sludgy cup only holds 12 ounces now. The same 4 ounces is now 33%. 100% is only 12, not 16.

e.g.
61 kWh / 76 kWh = 80% ... on day one this is your "80%" charge

After 5 kWh is lost to degradation the battery can no longer hold 76 kWh, it can only hold 71 kWh.

So if you charge to 61 kWh, you get: 61 kWh / 71 kWh = 86%

Your new "80%" charge is actually only 57 kWh.

Now if you flip to miles, on a LR AWD which uses 245 Wh/km as its internal constant ... 61 kWh is always 61 kWh is always 249 "dashboard miles".

That's your day 1 "80%" ... 249/310 = 80%
Your day 2000 "80%" is however, 57 kWh, which is only 233 miles.

"80%" on day 1 does not equal "80%" on day 2000.

If there's something here you don't understand, I would be happy to explain it further. If you just say "disagree" that doesn't mean much to me. Nothing above is an opinion. This is an explanation.

 

[darth_vad3r]

Quotes from a source you may enjoy, Tesla:
A Bit About Batteries

"Voltages over 4.15V/cell (about 95 percent state of charge [SOC]) and voltages below 3.00V/cell (about 2 percent SOC)"
"There is a huge difference in cycle life between a 4.2V/cell charge (defined by the manufacturers as “fully charged”) and a 4.15V/cell charge. 4.15 volts represents a charge of about 95 percent"
"charging to only 3.8V/cell (~50 percent) or 4.10V/cell (~90 percent) "

Tesla is saying here (that when they wrote this):
4.20 V = 100%
4.15 V = 95%
4.10 V = 90%
3.8 V = 50%
3.0 V = 2%

Percent is a measure of voltage. It doesn't tell you anything directly about your energy capacity. Energy is measured in kWh. This is based on voltage and the amp-hour capacity of the battery.

4.20 V can be measured across 1 single battery cell, or 31 batteries in parallel, or 46 batteries in parallel, or 46 degraded batteries in parallel. The % to voltage mapping doesn't change. The capacity increases with each cell you add in parallel though. The capacity also decreases with age, degradation, miscalibration, etc. You can also have different sized batteries like the 18650's in the S, X and the 2170's in the 3. The voltages have the same ranges because of the same basic chemistry type (Li-ion), but they have different capacities.

If elves snuck into your battery pack at night and disconnected one cell out of every brick, your car wouldn't notice right away. The voltage wouldn't change. Your percentage would not drop overnight. After a while of measuring usage and calibrating, it would realize your pack had degraded though. This would lower the car's estimate of your pack's total maximum capacity. It wouldn't change how it reported 0%, 50% 100% based on voltage.

 

[dmurphy]

I mean, it's a ROUGH estimator. If it's summer and I need to drive "100" and the battery says "150" I can probably make it.

Bravo. Well said. It’s EXACTLY the same thing that my last dozen ICE cars have done. A “xxx miles to empty” gauge on the dash. Rough estimate of remaining fuel, and for good measure, I tried to never get below 50 miles on that gauge, because it’s an estimate.

Exactly, exactly, exactly the same I do on my Model 3. Treat it as an estimate, and try to not get below about 50 miles to go.

Ain’t that hard to understand ....