Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health

[kevroc]

Hello all. Have had the car a month now (M3LR). Was curious about actual range given I typical drive under 50 miles per day. So this morning I checked. I started at 82%, then drove 20 miles. No crazy acceleration. Half highway at 70mph and half rural at 45mph. Took 7% battery. So that's 285. Obviously I was never expecting to get 358 but this seems significantly lower. Questions:.

1. Is this a fair way to calculate or will battery drainage slow at say under 10% for awareness purposes so you have to drain fully to get actual range?

2. If the answer to the above is yes then disregard. If not, does this sound low to you? Worth investigating further?

So, to answer the "Worth Investigating further?" question.

It is emphatically YES.

Here's the thing. The stated range by Tesla is based on a set of not necessarily real world driving conditions. Anything you do outside of that very narrow criteria they used it determining that stated range will affect YOUR actual usable range.

For instance, drive faster than their test speed (don't recall offhand what that is, 48mph maybe??) and you take a range hit. Drive like 80mph and take a significant hit. Drive in the wind, take a hit. Drive in the rain, take a hit. Drive on a dirt road (probably take a hit, haven't read that one but could assume). Drive when it's cold, take a hit.

So it is important to understand how YOUR driving habits affect the range and estimate your charging needs / charging stops appropriately. Just walking out the door thinking you're going to get 350 miles every time isn't a good idea.

Basically, actual achievable range changes based on environmental factors and driving habits.

It's a lot like how my laptop said it could get 9 hours of use on a charge. Well, I've never seen anything over 4 hours based on how I use it.

 

[jjrandorin]

So, to answer the "Worth Investigating further?" question.

It is emphatically YES.

Only if someone is interested in the "why is it like that" question.

My experience here tells me (over a very long period of time) that when people ask that question here, along with the other information that user posted (which is a variation of the same question that is in like 80% of the 4000+ posts in this thread), the "investigate further" statement means " Should I put in a service ticket to Tesla?"

And the answer to that, is emphatically NO.

Just from your short time here, it seems apparent to me that you like a bunch of data, which is fine. Thats not what the vast majority of the people who start off posting "So I drove X distance, and X+2 range came off my battery, do I have an issue with my car?" are getting at, though.

 

[kevroc]

Only if someone is interested in the "why is it like that" question.

My experience here tells me (over a very long period of time) that when people ask that question here, along with the other information that user posted (which is a variation of the same question that is in like 80% of the 4000+ posts in this thread), the "investigate further" statement means " Should I put in a service ticket to Tesla?"

And the answer to that, is emphatically NO.

Just from your short time here, it seems apparent to me that you like a bunch of data, which is fine. Thats not what the vast majority of the people who start off posting "So I drove X distance, and X+2 range came off my battery, do I have an issue with my car?" are getting at, though.

That's why I wanted to comment on that. Yes you should investigate, but not for the reason you may initially have thought.

As people transition from ICE to EV there's going to be a learning curve because not all of the relevant information is published. I know I average 22mpg when on the road, so if my next gas station is 100 miles I need 5 gallons or whatever. I've been doing it so long I don't think about it too much. I can add a buffer but I don't worry about stuff like wind or rain or whatever. It doesn't matter too much that the Manufacturer said it would get 28, I know what I get and that's enough for me. Whether my range is 300 or 400 miles won't make too much of a difference in my ICE life.

With EV's though it's different; 1) the range is shorter so your calcs need to be more precise. 2) the range changes due to battery degradation 3) environmental factors play a bigger role in how the affect range and 4) driving habits possibly play a bigger role.

So from an ICE where I may be in a range of 300 versus an EV where my range can be 150-300, I'm going to start to notice that more and potentially be a bit pre-occupied with it until I get the hang of it.

I still have a few months for delivery so I haven't read the manual yet, I don't know if all of that information is in there how not, but if it's not I certainly understand why that makes up for a lot of the posts. I will say that if Tesla isn't doing enough to educate their customers about that stuff then people should be contacting them. How else would Tesla know otherwise that they need to do a better job?

Yes, I do love my data , and these real world comments from owners on here is really priceless. It really is a great forum with a ton of useful information.

 

[jjrandorin]

That's why I wanted to comment on that. Yes you should investigate, but not for the reason you may initially have thought.

As people transition from ICE to EV there's going to be a learning curve because not all of the relevant information is published. I know I average 22mpg when on the road, so if my next gas station is 100 miles I need 5 gallons or whatever. I've been doing it so long I don't think about it too much. I can add a buffer but I don't worry about stuff like wind or rain or whatever. It doesn't matter too much that the Manufacturer said it would get 28, I know what I get and that's enough for me. Whether my range is 300 or 400 miles won't make too much of a difference in my ICE life.

With EV's though it's different; 1) the range is shorter so your calcs need to be more precise. 2) the range changes due to battery degradation 3) environmental factors play a bigger role in how the affect range and 4) driving habits possibly play a bigger role.

So from an ICE where I may be in a range of 300 versus an EV where my range can be 150-300, I'm going to start to notice that more and potentially be a bit pre-occupied with it until I get the hang of it.

I still have a few months for delivery so I haven't read the manual yet, I don't know if all of that information is in there how not, but if it's not I certainly understand why that makes up for a lot of the posts. I will say that if Tesla isn't doing enough to educate their customers about that stuff then people should be contacting them. How else would Tesla know otherwise that they need to do a better job?

Yes, I do love my data , and these real world comments from owners on here is really priceless. It really is a great forum with a ton of useful information.

Sure, all true, and no, tesla doesnt provide a lot of data. At a macro level, most people just have to adjust to not needing to know "22 MPG till" etc, because, most people should be charging at home so unless they are running their entire range out on a trip, all that is completely a moot point unless someone just is into the data.

Doesnt matter if I can go 150 miles on a charge or 300 miles on a charge if my commute is 50 miles per day and I charge at home every day (as an example). In a gas car, you drive it down till you have to go to the gas station and go fill back up, so you need to know that stuff because everyone is usually "pushing it" in some manner. In an EV, for the VAST majority of the time, unless you are going farther than your cars range that day, it doesnt really matter except for an academic exercise.

So, people have to get used to the fact that it kind of doesnt matter, for daily use, unless they want it to matter. For most people thats fine, for data hounds it isnt, but like I said, thats totally fine, and there is a "LOT" of data you can get from the car should you be inclined to do so.

For the vast majority, though, they just are in this "I bought a car with 300 mile range, how come I drove 20 miles and 30 miles rolled off the mileage?!!? I need to call tesla right??? I called tesla and they told me its normal, they SUCKKKKKK!!!1111!!!11!!1!!" Place.

 

[Steve446]

Sure, all true, and no, tesla doesnt provide a lot of data. At a macro level, most people just have to adjust to not needing to know "22 MPG till" etc, because, most people should be charging at home so unless they are running their entire range out on a trip, all that is completely a moot point unless someone just is into the data.

Doesnt matter if I can go 150 miles on a charge or 300 miles on a charge if my commute is 50 miles per day and I charge at home every day (as an example). In a gas car, you drive it down till you have to go to the gas station and go fill back up, so you need to know that stuff because everyone is usually "pushing it" in some manner. In an EV, for the VAST majority of the time, unless you are going farther than your cars range that day, it doesnt really matter except for an academic exercise.

So, people have to get used to the fact that it kind of doesnt matter, for daily use, unless they want it to matter. For most people thats fine, for data hounds it isnt, but like I said, thats totally fine, and there is a "LOT" of data you can get from the car should you be inclined to do so.

For the vast majority, though, they just are in this "I bought a car with 300 mile range, how come I drove 20 miles and 30 miles rolled off the mileage?!!? I need to call tesla right??? I called tesla and they told me its normal, they SUCKKKKKK!!!1111!!!11!!1!!" Place.

There's something about Tesla drivers that really brings this battery and range thing to the foreground over many other topics (I'm one too so equally guilty). As mentioned, there are >4000 posts here on the subject. As you say, for most people it really doesn't matter they just want to point and go there. I guess though that there's an argument for a broader, straight forward information source for BEV batteries, free of press bias that people can go to, that provides a more level playing field on the issue - one that most non-detail orientated folks can align with. Maybe many of the questions would then go away.

 

[jjrandorin]

There's something about Tesla drivers that really brings this battery and range thing to the foreground over many other topics (I'm one too so equally guilty). As mentioned, there are >4000 posts here on the subject. As you say, for most people it really doesn't matter they just want to point and go there. I guess though that there's an argument for a broader, straight forward information source for BEV batteries, free of press bias that people can go to, that provides a more level playing field on the issue - one that most non-detail orientated folks can align with. Maybe many of the questions would then go away.

My personal feeling is, simply, "because its new" and also because there is a lot of mis information out there from parties that do not want EVs to succeed, for various reasons.

Couple that with the "EPA test" (WLTP also) thing (which is very similar to petrol / gas cars, but no one cares), and we end up where in that place above, I mentioned.

 

[krisroxx]

I snuck over and gave you some charge during the night.

 

[kevroc]

Sure, all true, and no, tesla doesnt provide a lot of data. At a macro level, most people just have to adjust to not needing to know "22 MPG till" etc, because, most people should be charging at home so unless they are running their entire range out on a trip, all that is completely a moot point unless someone just is into the data.

Doesnt matter if I can go 150 miles on a charge or 300 miles on a charge if my commute is 50 miles per day and I charge at home every day (as an example). In a gas car, you drive it down till you have to go to the gas station and go fill back up, so you need to know that stuff because everyone is usually "pushing it" in some manner. In an EV, for the VAST majority of the time, unless you are going farther than your cars range that day, it doesnt really matter except for an academic exercise.

So, people have to get used to the fact that it kind of doesnt matter, for daily use, unless they want it to matter. For most people thats fine, for data hounds it isnt, but like I said, thats totally fine, and there is a "LOT" of data you can get from the car should you be inclined to do so.

For the vast majority, though, they just are in this "I bought a car with 300 mile range, how come I drove 20 miles and 30 miles rolled off the mileage?!!? I need to call tesla right??? I called tesla and they told me its normal, they SUCKKKKKK!!!1111!!!11!!1!!" Place.

So I get that, and I don't disagree...to a point. But most peoples cars serve as their daily commute cars and also their cars for everything else. Get a call about you sick mom in the middle of the night and have to road trip the next morning? Jump in the car, get gas on the way out no big deal. . Wanna do a trip up to Yosemite or Joshua Tree or out to Disneyland this weekend? No problem. Your current commute is San Diego to Poway but then find out you are moving to Murrieta? ICE no problem. Tesla?? Well, start doing the math... My point it, while for daily commute I agree, plug and play (I guess that would be plug and drive) it's as painless as could be. But peoples cars serve many purposes and if you don't learn the math and battery impacts it's going to be a rude awakening. Personally I would prefer to learn that upfront in a pro-active manner rather then at 3 in the morning when I'm supposed to leave in a few hours...

With ICE, it's nice how they do advertise City vs HWY MPG. So you start right off the bat with the understand that "oh, so the efficiency of the car differs based on how I am driving it, okay...good to know"

With Tesla, it's "353 Miles". Period. Okay, so that's my expectation, anything different from that and I think there's a problem with the car.

 

[jjrandorin]

So I get that, and I don't disagree...to a point. But most peoples cars serve as their daily commute cars and also their cars for everything else. Get a call about you sick mom in the middle of the night and have to road trip the next morning? Jump in the car, get gas on the way out no big deal. . Wanna do a trip up to Yosemite or Joshua Tree or out to Disneyland this weekend? No problem. Your current commute is San Diego to Poway but then find out you are moving to Murrieta? ICE no problem. Tesla?? Well, start doing the math.

You dont have one yet so sure, you think this. the only one of your scenarios that even requires thought is that yosemite trip (if you have decent home charging) The rest is a non issue (said as someone who has had one for 3.5 years). My car charges at 42 miles of range an hour, because I was worried about all that stuff you laid out when I bought it and setup home charging.

I live in temecula (northern edge actually) and "to poway" or "to san diego" or "to chula vista" is the same non issue from my house. No calculation needed.

Havent needed that charge speed once, but I have it. That means I can get 120 miles range in 3 hours. The "sick mom in middle of night but road trip in the morning would be "return home, plug in, get up and leave at same time and hit a supercharger when needed".

It seriously isnt an issue, if you have 240v home charging (I would not own one of these without it, personally).

 

[Zoomit]

and miles will never roll off at 1:1 unless you drive like the EPA test which is done at no elevation changes and a max speed of 48 MPH.

For instance, drive faster than their test speed (don't recall offhand what that is, 48mph maybe??) and you take a range hit. Drive like 80mph and take a significant hit. Drive in the wind, take a hit. Drive in the rain, take a hit. Drive on a dirt road (probably take a hit, haven't read that one but could assume). Drive when it's cold, take a hit.

You might be surprised to learn that the 5-cycle EPA testing goes up to 80 mph, albeit only briefly. The average on the highway and high speed tests is 48 mph and the average speed on the other three is 21 mph.

Detailed Test Information

EPA tests vehicles by running them through a series of driving routines, or schedules, that specify vehicle speed for each point in time during the laboratory tests.

www.fueleconomy.gov

The crossover point for steady-state highway cruising is typically between 60-65 mph. So if you're cruising on the highway at about 60 mph or so you'll go the EPA range. All these caveats apply:

No drafting
No accelerations due to traffic
No elevation change
No wind
Mild temperatures
No HVAC use
No rain or snow
Smooth road surface
Cold tire pressure set to door jam spec
OEM wheels and tires
Suspension alignment to spec
Battery aged by 4000 mi
Driver weight + cargo: 300 lbs
Probably more I'm not remembering right now

 

[Siciliano]

So I just took my first semi-long trip, which is about 3.5 hours away and 222 total miles. I have a bit of range loss - which is expected because it's a 2018 - so fully charged it shows 290 miles. On the way there I had to stop to charge but didn't really pay attention to miles charged /driven etc...

So after my stay and a full charge at my destination, I had to stop at a supercharger on the way home that's only 163 miles away, and I have only about 32 miles of range left. That puts the *actual* range at about 195 miles, which is crazy. It's 50 degrees out (not cold), I was going about 75mph on smooth highways the entire time, and it's not hilly or windy. How can you advertise 300 miles range when it's really 35% less?!

I LOVE everything else about the car, but this is unacceptable and really disappointing...if I knew this before I bought the car, I'm not sure that I would have bought it (especially if my wife knew about it! lol)

 

[jjrandorin]

I was going about 75mph

 

[KenC]

So I just took my first semi-long trip, which is about 3.5 hours away and 222 total miles. I have a bit of range loss - which is expected because it's a 2018 - so fully charged it shows 290 miles. On the way there I had to stop to charge but didn't really pay attention to miles charged /driven etc...

So after my stay and a full charge at my destination, I had to stop at a supercharger on the way home that's only 163 miles away, and I have only about 32 miles of range left. That puts the *actual* range at about 195 miles, which is crazy. It's 50 degrees out (not cold), I was going about 75mph on smooth highways the entire time, and it's not hilly or windy. How can you advertise 300 miles range when it's really 35% less?!

I LOVE everything else about the car, but this is unacceptable and really disappointing...if I knew this before I bought the car, I'm not sure that I would have bought it (especially if my wife knew about it! lol)

My car still shows 310miles of range, same as original. My efficiency measures at 235Wh/mile @ 65mph, according to ABRP, which means I could go 310 miles if I drove 65mph. I don't. At 80mph, I use about 275Wh/mile, so I'm not going to get 310 miles of range when I'm going way above the speed limit.

However, on my 4400 mile trip I took this late Summer, the longest leg between charges was 141 miles. That's not because my battery range was no good, but because the fastest way to road trip is to drive FAST, and charge at low SOC, and then only up to about 65%, since charging speeds slow down at higher SOCs. Charging from 10% to 65% or so, means I've got between 120 to 140 miles before my next fast stop of about 15mins of charging. That's the fastest way to road trip, so having 300 miles of range never comes into question.

In your case, you've fallen into the trap where you could conceivably do a trip without charging, but why? To do the trip, you'd have to do it at a speed, that you'll find unacceptably slow. Drive fast, stop and charge for a few minutes, and don't worry about it.

 

[Jejunjm]

Good introductory physics here

Car Physics: From Physclips

Car physics. Acceleration, force, power, distance, drag coefficient, air resistance. Wheel stands, wheelies. This gives some car-related problems from kinematics and mechanics. Solar car examples. Animations and video film clips. Physclips provides multimedia education in introductory physics...

www.animations.physics.unsw.edu.au

 

[Siciliano]

I think you guys are missing the point. I'm well aware of the physics... my gripe is with the false advertisement. If I went to pick up the car and the sales rep told me, "Oh, by the way, that 300 miles of range you see there...that only applies if you drive 65 mph or less in a total vacuum. If you go even 75mph your range will be more like 190ish." I honestly might have walked away.

This should be told to the buyer up front. It's a misrepresentation at best, and a flat out lie at worst. In no universe its 75mph "fast", and the customer shouldn't have to do physics calculations. Obviously I know battery life depends on the driver's behavior... if you floor it at every stoplight, then I'd completely understand the decreased range, but we're talking about a very steady speed, all highway driving.

 

[Apprunner]

I think you guys are missing the point. I'm well aware of the physics... my gripe is with the false advertisement. If I went to pick up the car and the sales rep told me, "Oh, by the way, that 300 miles of range you see there...that only applies if you drive 65 mph or less in a total vacuum. If you go even 75mph your range will be more like 190ish." I honestly might have walked away.

This should be told to the buyer up front. It's a misrepresentation at best, and a flat out lie at worst. In no universe its 75mph "fast", and the customer shouldn't have to do physics calculations. Obviously I know battery life depends on the driver's behavior... if you floor it at every stoplight, then I'd completely understand the decreased range, but we're talking about a very steady speed, all highway driving.

The EPA of 300 miles isn't all highway. Its a mix of highway and city. Case in point, I drove mostly city today to get to work and my wh/mi was 150. That implies a range of nearly 500 miles. The EPA methodology is the culprit. They should state 2 numbers...highway and city. I bet Highway is no more than 250 miles at 60mph.

 

[beenmb]

There is absolutely zero reason (for the car) to change the amps from 12a to 10a or 8a (none). ALL home charging (including 240v 48amp) is "slow" to the car. All you are doing on the car side is keeping the car awake longer because it doesnt sleep when its charging. Keeping the car awake longer = more power used in general, because there is overhead for energy use for the car being awake.

TL ; DR -- It wont matter to the car at all, but there isnt any reason on the CAR side to do this at all, because you are just keeping the car awake longer and wasting energy. If you have a reason to do this because its not a dedicated circuit or something thats one thing. For the CAR? no reason at all to turn it down.

Good to know. Thanks.

 

[beenmb]

There is absolutely zero reason (for the car) to change the amps from 12a to 10a or 8a (none). ALL home charging (including 240v 48amp) is "slow" to the car. All you are doing on the car side is keeping the car awake longer because it doesnt sleep when its charging. Keeping the car awake longer = more power used in general, because there is overhead for energy use for the car being awake.

TL ; DR -- It wont matter to the car at all, but there isnt any reason on the CAR side to do this at all, because you are just keeping the car awake longer and wasting energy. If you have a reason to do this because its not a dedicated circuit or something thats one thing. For the CAR? no reason at all to turn it down.

Ok thanks good to know the car doesn't care. The outlet can get very warm to the touch when the car is pulling 12A. Not hot at 10A or 8A. Maybe cheap builder grade wiring and outlets causes that?

 

[jjrandorin]

Ok thanks good to know the car doesn't care. The outlet can get very warm to the touch when the car is pulling 12A. Not hot at 10A or 8A. Maybe cheap builder grade wiring and outlets causes that?

Could be. Note that I said it didnt matter to the car, but I didnt say "it doesnt matter to the outlet". Most outlets are shared amongst other things. That outdoor outlet is likely shared among other devices at your home.

Outlets for car charging are supposed to be dedicated ones, but its very common for a home not to have dedicated outlets anywhere that you could normally plug in, or for those outlets to be dedicated for something else (like a dryer).

I think I would start with replacing the outlet, and making sure everything is torqued down properly on the outlet. "very warm" with electricity is a bad sign, and I would not want to trust a potential fire to "but I turned down the amps in the car to 8amps".

 

[philly4]

my gripe is with the false advertisement

In the nicest way possible...your gripe should be to yourself for not becoming educated on what the EPA range means before making a buying decision. Tesla (nor any other car maker) doesn't advertise anything besides what the EPA dictates...it's regulated.

Perhaps as secondary, your gripe should be to the EPA for making thier EV range test not very "real world" and allowing manufacturers to advertise a combined range without clearly breaking out highway and city like they do for ICE cars. I'm sure there's politics involved to get the numbers high to promote adoption...so they are more near best case scenario.

That being said, the more efficient a car gets, (EVs) the more variation there will be in range in the real world. There's no way around that so it's not really possible to distil real world range down to a single number for the public without being quite optimistic or pessimistic. Maybe a range range?