[UK] 2022.12.x

[spdpsba]

You might be onto something with your first point @Durzal

Your final point I'd disagree with however - the 'inaccurate measure' is more meaningful than % in terms of the distance the car is capable of driving. (Yes, I know 'other factors etc, etc') Knowing the car quotes say 140 miles means I'm very unlikely to drive 180 miles, but likely good for 100 in most circumstances. What does 42% tell me, other than that's the current level of the battery. Using a % still means you need to make your own assumption about what distance is possible. We are simply debating the starting point to use.

As I said earlier, horses for courses - without the need to patronise.

Agree and Tesla itself settled this debate by giving us the option to check both when the %supporters were all up in arms regarding why everyone should use % with all their analogies. In the middle of no where 42% may roughly tell me I can do around 120 miles after doing a calculation based on whatever I ve done in the past - But again all the other factors like how you drive, inclination, head wind and temperature all will play a role - so 42% is 42%. The only thing I know is I have to charge when it touches 10% so that I am not going to get stuck. And so I can reasonably use another 30% - if that is of any help.

 

[Adopado]

As above but the SR+ on road without LFP batteries aren’t in huge numbers. But the point I was making is responding to @Durzel of why Tesla removed that feature.

We know what you meant in response to Durzel ... we were just correcting your comment specifically about the SR+ model. It's not the biggest issue in the world but you still seem to be defending your inaccurate statement ... as in: "As above but the SR+ on road without LFP batteries aren’t in huge numbers." ... why are you continuing with this?

 

[Durzel]

You might be onto something with your first point @Durzal

Your final point I'd disagree with however - the 'inaccurate measure' is more meaningful than % in terms of the distance the car is capable of driving. (Yes, I know 'other factors etc, etc') Knowing the car quotes say 140 miles means I'm very unlikely to drive 180 miles, but likely good for 100 in most circumstances. What does 42% tell me, other than that's the current level of the battery. Using a % still means you need to make your own assumption about what distance is possible. We are simply debating the starting point to use.

As I said earlier, horses for courses - without the need to patronise.

It's a fair point to say that if your car has 42% charge then you don't really know when you're using the app without calculating it in your head how far that actually would be in miles. That said, you can find out when you're in the car by tapping the battery icon so if you're actually about to drive anywhere you can find out.

I would say when it comes to charging you presumably aren't going to charge up to an odd percentage, you're either going to do it to 100% (in the case of LFP batteries) or a fraction that you can easily work out (e.g. 50%, 75%, etc). So, in those situations how do you benefit from knowing the miles estimated when its a simple mental calculation?

I've got a M3P which had a reported 310 (I think) miles from new. If I charged it to 100% I know it would claim to be able to do around 300 miles, so I know if its on 50% I can apparently do about 150 in idealised conditions, and either side of 50% would be more or less than that. I would know that I should aim to be charging anywhere around the 20% mark (less than 25% I think you lose Sentry, etc).

I happen to think people should drive to the percentage rather than "remaining miles" in an EV, and plan to charge at a reasonable - but not too low - percentage remaining. Since the scale is 0-100 it will go down more linearly (but still not linear) than 0-300 would, for example, so you're less likely to be caught out when driving. Plus, it's good practice in my opinion to aim to charge well before you are desperate to charge. I keep seeing posts on Tesla FB groups of people running out of charge to the point their car shuts down and am lost for words about it really. The whole point of EVs is that, like a phone, you charge as often as you have the opportunity to, not run it down to the fuel light like you would in an ICE. In that context using miles rather than percent just lulls people into a false sense of security for no good reason.

 

[HenryT]

It's a fair point to say that if your car has 42% charge then you don't really know when you're using the app without calculating it in your head how far that actually would be in miles. That said, you can find out when you're in the car by tapping the battery icon so if you're actually about to drive anywhere you can find out.

I would say when it comes to charging you presumably aren't going to charge up to an odd percentage, you're either going to do it to 100% (in the case of LFP batteries) or a fraction that you can easily work out (e.g. 50%, 75%, etc). So, in those situations how do you benefit from knowing the miles estimated when its a simple mental calculation?

I've got a M3P which had a reported 310 (I think) miles from new. If I charged it to 100% I know it would claim to be able to do around 300 miles, so I know if its on 50% I can apparently do about 150 in idealised conditions, and either side of 50% would be more or less than that. I would know that I should aim to be charging anywhere around the 20% mark (less than 25% I think you lose Sentry, etc).

I happen to think people should drive to the percentage rather than "remaining miles" in an EV, and plan to charge at a reasonable - but not too low - percentage remaining. Since the scale is 0-100 it will go down more linearly (but still not linear) than 0-300 would, for example, so you're less likely to be caught out when driving. Plus, it's good practice in my opinion to aim to charge well before you are desperate to charge. I keep seeing posts on Tesla FB groups of people running out of charge to the point their car shuts down and am lost for words about it really. The whole point of EVs is that, like a phone, you charge as often as you have the opportunity to, not run it down to the fuel light like you would in an ICE. In that context using miles rather than percent just lulls people into a false sense of security for no good reason.

In terms of mileage expectation I think we all do exactly the same thing, the only difference being where we prefer to start the calculation from.

Other than that, agree entirely with your observations.

 

[spdpsba]

We know what you meant in response to Durzel ... we were just correcting your comment specifically about the SR+ model. It's not the biggest issue in the world but you still seem to be defending your inaccurate statement ... as in: "As above but the SR+ on road without LFP batteries aren’t in huge numbers." ... why are you continuing with this?

Are they in huge numbers? - sorry don’t understand what you are getting at?

 

[spdpsba]

The whole point of EVs is that, like a phone, you charge as often as you have the opportunity to, not run it down to the fuel light like you would in an ICE. In that context using miles rather than percent just lulls people into a false sense of security for no good reason.

Is there an assumption that people who use percentage has the ability to covert that to miles, also they can sensibly make a charging decision but people who use miles are bit ignorant of these nuances and then run it down to the fuel light like would in an ICE?

Btw, the phone analogy is not the right one and not everyone with a phone charge as often as they get the opportunity to charge. In fact most people try their best to charge at the end of their day unless you have an old phone with the measure of battery capacity below 80% relative to when it was new.

 

[Adopado]

Are they in huge numbers? - sorry don’t understand what you are getting at?

You said "Most of SR+ owners charge to 100% most of the time" I was simply pointing out the inaccuracy of that statement. It's no huge deal except for the fact that you have decided to pursue it further by challenging the idea that there are lots of SR+ Teslas that don't have LFP batteries and therefore don't frequently charge to 100% ... when evidently there are!

Yes there are huge numbers of SR+ Model 3s that don't have the LFP battery pack! Not surprising since they have been selling the SR+ since 2018 in the States and since 2019 in the UK yet the SR+ with LFP battery only started being sold later last year.

 

[browellm]

It's a bit like arguing for Fahrenheit vs Celsius. Yes Fahrenheit works, but why make things difficult for yourself

 

[spdpsba]

Most of SR+ owners charge to 100% most of the time, so we do not have to slide it at the point of charging to check the BMS and that is one of the reasons I wasn’t sure why would someone even need that feature.

From existing data other than Europe in most other regions it is SR that is the high volume seller.

Whether people are contacting Tesla or not if this is to reassure the customers then the SR customers still will contact Tesla and that is a huge number. I have seen my BMS total miles drop from 262 to 256 in a year and every time I charge to 100% (3 times a week) I see the BMS calculated miles and I don’t have to move the slider.

This should read, most of LFP owners and SR should read RWD as @Adopado corrected. That was what I implied and knowing Tesla had different combinations of this I should have been more specific.

 

[Adopado]

We routinely measure a petrol/diesel car by it's estimated mileage. Even though modern cars can show a range figure we say we've got a quarter of a tank left, or a nearly full tank ... you might occasionaly say "I'm running on fumes but the car says I've got 20 miles left" but that's about the only time the mileage is helpful (if you believe it). Same on an EV ... as the battery gets worryingly low you are likely to start counting down the miles but it is less useful at higher percentages. It's handy to have access to the miles readout as an option but I'll stick to the equivalent of "half a tank" i.e. 50% battery.

 

[spdpsba]

We routinely measure a petrol/diesel car by it's estimated mileage. Even though modern cars can show a range figure we say we've got a quarter of a tank left, or a nearly full tank ... you might occasionaly say "I'm running on fumes but the car says I've got 20 miles left" but that's about the only time the mileage is helpful (if you believe it).

I am being pedantic here, the ‘We’ here means? Everyone?

Same on an EV ... as the battery gets worryingly low you are likely to start counting down the miles but it is less useful at higher percentages. It's handy to have access to the miles readout as an option but I'll stick to the equivalent of "half a tank" i.e. 50% battery.

I got my licence only in late 90s and I hardly heard my generation saying ‘half a tank’ and we were all spoilt by range figures from the beginning. I hope the % believers get the drift. It is just a generation thing in terms of the terminology we are used to.

 

[spdpsba]

Not surprising since they have been selling the SR+ since 2018 in the States and since 2019 in the UK yet the SR+ with LFP battery only started being sold later last year.

I have a 2021 Q1 SR+ with LFP batteries - so it started selling from Q1 last year. We all inadvertently make mistakes with some of these things.

 

[HenryT]

We routinely measure a petrol/diesel car by it's estimated mileage. Even though modern cars can show a range figure we say we've got a quarter of a tank left, or a nearly full tank ... you might occasionaly say "I'm running on fumes but the car says I've got 20 miles left" but that's about the only time the mileage is helpful (if you believe it). Same on an EV ... as the battery gets worryingly low you are likely to start counting down the miles but it is less useful at higher percentages. It's handy to have access to the miles readout as an option but I'll stick to the equivalent of "half a tank" i.e. 50% battery.

I had a BMW motorbike which had a bizarre way of quoting fuel level. It would show range until you got down to about 35 miles then just a warning to get fuel - no range quoted, but from that point it would begin to show the miles you have done since the warning, increasing as you went on. The fuel level was represented by 5 bars so when you were on the last one you really had no idea how far you had left if you hadn't been keeping count.

(And yes, it did catch me out more than once.)

 

[qwickshot]

I’m fairly sure the answer is a simple one, to declutter the app of ‘unnecessary information’.

It’s the exact same principle they have been applying to the cars internal UI.

It’s very much the modern approach to UI design and generally speaking ‘normal’ users find having less information and less buttons to press easier to use (or how a UI designer may describe it has having a lower cognitive load).

However, that approach has drawbacks in that it infuriates ‘power users’ but in reality, those people make up a fraction of the actual user base.

If you pay any attention to the software space you’ll see the trend of less options/buttons/information with things organised into simple (but sometimes very long) menu trees all over. For example back in the day, windows mobile was far more functional than iOS but iOS killed it off because it’s so simple a 3 year old can operate it meanwhile fully grown adults are scratching their head looking at windows mobile (and still do with the modern desktop versions).

 

[WannabeOwner]

What does 42% tell me, other than that's the current level of the battery

As you rightly point out there are two choices, Happens that I prefer percent, and here's my illustration of why:

My approach is "Multiple percent by miles-per-percent". I find this easier than "Deduct a proportion from miles range given".

You do need a value for "Miles-per-percent" for your car. I reckon that a whole number will do for that, except in some marginal cases.

Miles-per-percent [for cars with a real-world range between 200 and 300 miles] is a number between 2 and 4. Using a whole number approximation may be plenty good enough (and the maths therefore easy). Using a 0.5 number is more accurate, but unless the car has a range of less than 200 miles I don't think it is necessary

If the actual real-world range is 300 miles then using a 0.5 multiplier (instead of using the nearest whole number) is going to make a maximum difference of 16 miles ... 5% error. And that requires that the actual [accurate multiple] is at a maximum difference of either +/- 0.5. If the actual difference is less than +/- 0.4 the error will be less than 5%

If the actual real-world range is only 200 miles then using a whole-number multiplier has a maximum error of 12.5%, so for a car with absolute max range 200 miles then using a 0.5% multiple would be better (6% error at worst) - but that is only necessary if you are unfortunate enough that a) the car is down around 200 miles range AND b) the accurate multiplier-number is closer to a 0.5 value than a whole number.

I am assuming that most people can do 2x, or 3x or 4x any 0-100 number relatively easily in their head.

Personally (and I'm good at maths, generally, but dyslexic so probably some lack of ability because of that) I think that is easier than deducting X% from the range miles (i.e. a number between 0 and 300)

If the car has 248 mile range shown which is actually 207 real-world miles then have to deduct 20% - how do you do that? Multiple by 0.8 - I definitely can't do that in my head. Take 20% off? I can do that - I would take 10% (drop the last digit - round if you like), double it, then subtract it from the original ... if I'm doing that whilst I'm driving along I'll probably lose my place marker between those steps!

What if it was 15% ... so that's the 10% drop-last-digit-thing, then halve it, then add the two together, then deduct that from the range-miles.

Maybe other folk have much better ways of doing the mental-maths for deduct 15%, 20%, 25%, 30% (i'm guessing that is about the range of percent that needs deducting, if it is actually in the 30 - 40% range I think the mental maths is much harder)

Just curious whether anyone has a smart way of doing that particular sum.

My view of the percent route is that I need to multiple my current percent - let's say that is 43% - by 3. Or if I drive very economically then x 4, or if I have a smaller battery then maybe x 2. All you need is to have "discovered" what that multiplier is. If weather is terrible - wet / cold - then knock 0.5 off the multiplier (for a very pessimistic value).

That was just to articulate how, in practice, I use the percentage number.

But all that apart: I would use SatNav and Consumption : {TRIP] display. Put the destination into SatNav. If I can't get there SatNav will show me a suitable Supercharger to charge at. Either way, I can then look at Consumption : {TRIP] display and see what percentage it predicts for arrival. If that is close to 10% I am going to drive carefully (or choose a nearer charging location ...), if it is more than 20% I can press on ... as I drive I can review how prediction-vs-actual looks, and the closer I get the more confident I am that anything 20% and up means I can press on ... if the numbers have dropped towards 10% (e.g. wet roads from an unexpected thunderstorm in summer) I can slow up, or look for somewhere to charge.

Personally I'm only using the mental-maths to decide if it is "likely doable", and I'm then going to use SatNav and Consumption to double check my maths.

When I'm sat Supercharging I press "Continue trip", then the Consumption : [TRIP] graph changes to be from "here" to the next destination. If I haven't charged enough it will show "negative arrival percentage", that will keep nudging up as the battery fills up, and I can just wait until predicted-arrival has moved up to 10% ... or maybe nearer to 20% to be sure ... and then I can set off.

We routinely measure a petrol/diesel car by it's estimated mileage.

Now that you remind me of that ... that was always rubbish. I don't know why, but my recollection of the ICE cars (not since 2015 Hooray!) the last 50 miles or so went down much more quickly than the first 550 miles. I assume the shape of the tank meant that the bottom was "conical" in some manner, and the measuring-device was linear. I always thought that was pants - how hard would it have been for the computer that provided the digital readout of miles-to-empty to adjust / compensate for the actual shape of the tank. So when I most needed accurate range, because I was below 50 miles and the next filling station was 40 miles away, the car actually used up those 50 miles, driving at 50 MPH behind a truck!, in 25 miles

I had a BMW motorbike which had a bizarre way of quoting fuel level. It would show range until you got down to about 35 miles then just a warning to get fuel - no range quoted

Yeah, I had a VW Golf Blue Motion (or maybe the RS4 several cars before that) which did that. "We'd hate for you to think you have enough, so now that we have clicked over from 10 miles to 9 we are going to show "- - -" instead ...).

 

[GRiLLA]

As you rightly point out there are two choices, Happens that I prefer percent, and here's my illustration of why:

My approach is "Multiple percent by miles-per-percent". I find this easier than "Deduct a proportion from miles range given".

You do need a value for "Miles-per-percent" for your car. I reckon that a whole number will do for that, except in some marginal cases.

Miles-per-percent [for cars with a real-world range between 200 and 300 miles] is a number between 2 and 4. Using a whole number approximation may be plenty good enough (and the maths therefore easy). Using a 0.5 number is more accurate, but unless the car has a range of less than 200 miles I don't think it is necessary

If the actual real-world range is 300 miles then using a 0.5 multiplier (instead of using the nearest whole number) is going to make a maximum difference of 16 miles ... 5% error. And that requires that the actual [accurate multiple] is at a maximum difference of either +/- 0.5. If the actual difference is less than +/- 0.4 the error will be less than 5%

If the actual real-world range is only 200 miles then using a whole-number multiplier has a maximum error of 12.5%, so for a car with absolute max range 200 miles then using a 0.5% multiple would be better (6% error at worst) - but that is only necessary if you are unfortunate enough that a) the car is down around 200 miles range AND b) the accurate multiplier-number is closer to a 0.5 value than a whole number.

I am assuming that most people can do 2x, or 3x or 4x any 0-100 number relatively easily in their head.

Personally (and I'm good at maths, generally, but dyslexic so probably some lack of ability because of that) I think that is easier than deducting X% from the range miles (i.e. a number between 0 and 300)

If the car has 248 mile range shown which is actually 207 real-world miles then have to deduct 20% - how do you do that? Multiple by 0.8 - I definitely can't do that in my head. Take 20% off? I can do that - I would take 10% (drop the last digit - round if you like), double it, then subtract it from the original ... if I'm doing that whilst I'm driving along I'll probably lose my place marker between those steps!

What if it was 15% ... so that's the 10% drop-last-digit-thing, then halve it, then add the two together, then deduct that from the range-miles.

Maybe other folk have much better ways of doing the mental-maths for deduct 15%, 20%, 25%, 30% (i'm guessing that is about the range of percent that needs deducting, if it is actually in the 30 - 40% range I think the mental maths is much harder)

Just curious whether anyone has a smart way of doing that particular sum.

My view of the percent route is that I need to multiple my current percent - let's say that is 43% - by 3. Or if I drive very economically then x 4, or if I have a smaller battery then maybe x 2. All you need is to have "discovered" what that multiplier is. If weather is terrible - wet / cold - then knock 0.5 off the multiplier (for a very pessimistic value).

That was just to articulate how, in practice, I use the percentage number.

But all that apart: I would use SatNav and Consumption : {TRIP] display. Put the destination into SatNav. If I can't get there SatNav will show me a suitable Supercharger to charge at. Either way, I can then look at Consumption : {TRIP] display and see what percentage it predicts for arrival. If that is close to 10% I am going to drive carefully (or choose a nearer charging location ...), if it is more than 20% I can press on ... as I drive I can review how prediction-vs-actual looks, and the closer I get the more confident I am that anything 20% and up means I can press on ... if the numbers have dropped towards 10% (e.g. wet roads from an unexpected thunderstorm in summer) I can slow up, or look for somewhere to charge.

Personally I'm only using the mental-maths to decide if it is "likely doable", and I'm then going to use SatNav and Consumption to double check my maths.

When I'm sat Supercharging I press "Continue trip", then the Consumption : [TRIP] graph changes to be from "here" to the next destination. If I haven't charged enough it will show "negative arrival percentage", that will keep nudging up as the battery fills up, and I can just wait until predicted-arrival has moved up to 10% ... or maybe nearer to 20% to be sure ... and then I can set off.



Now that you remind me of that ... that was always rubbish. I don't know why, but my recollection of the ICE cars (not since 2015 Hooray!) the last 50 miles or so went down much more quickly than the first 550 miles. I assume the shape of the tank meant that the bottom was "conical" in some manner, and the measuring-device was linear. I always thought that was pants - how hard would it have been for the computer that provided the digital readout of miles-to-empty to adjust / compensate for the actual shape of the tank. So when I most needed accurate range, because I was below 50 miles and the next filling station was 40 miles away, the car actually used up those 50 miles, driving at 50 MPH behind a truck!, in 25 miles



Yeah, I had a VW Golf Blue Motion (or maybe the RS4 several cars before that) which did that. "We'd hate for you to think you have enough, so now that we have clicked over from 10 miles to 9 we are going to show "- - -" instead ...).

I agree with some of what you are saying, but I would suggest you are making it sounds far more complex than necessary.

I have two modes of driving, short journeys and then occasionally long journeys.

If it's a long journey I will have planned the route using the car sat nav (sometimes with ABRP before I go). Only this gives sufficient accuracy to be realistic. I would never just 'hope' based on some mileage figure.

If it's a short journey, I know I don't need to think about the available battery, as long as it was charged as usual to 80% the night before, it's never going to come anywhere close to using the battery. Generally I won't even use the navigation. If the car is above 20% as a leave it will be fine, guaranteed.

So, what's the need for the range at all, well it's really for validate that my charge overnight completed as expected. Sometimes the 4 hours of Go isn't sufficient to get me back to 80% etc. This is far more sensible to look at in terms of percentage, rather than a changing figure for a number of miles. Even folks who set the view to miles use the indents in the charging figure to set it to 70, 80, 90% etc. LFP Battery people charge to 100%, you would be weird to say you charge to some number of miles.

So, what's the value of having it set to miles rather than percent, sounds to me that people are just confusing themselves. To be honest I also don't really know how far away anything it in miles, just doesn't seem to be anything that's worth retaining.

 

[WannabeOwner]

I have two modes of driving

yes, that's a good point. I have those two modes too.

I also have a third mode - The car is only part charged and I'm going somewhere a fair distance, or wifee says "I'm off to Y have I got enough juice". That's when I use the mental-maths approximation for "roughly how far can current SOC get me". If that number is "tight" (e.g. when the car is only part charged) then I'll use ABRP or car's SatNav to check more accurately.

I would suggest you are making it sounds far more complex than necessary.

Definitely! That was only intended to "show my working" (and in particular in case someone checking it points out that I've got it wrong ...)

To summarise I think:

1. To get from Percent to Reasonably-accurate-Range can be done using multiple by (most likely) a whole number which will be 2, 3, or 4

In some cases (particularly cars with max range closer to 200 miles) that might need multiple by X-and-a-half (where X is 2, 3 or 4)

2. To get from Rated Miles to Reasonably-accurate-Range needs deduct-a-percentage, which is likely to be somewhere between 20% and 40%

I think the first is easier to do, in my head, than the second.

 

[WannabeOwner]

To be honest I also don't really know how far away anything it in miles, just doesn't seem to be anything that's worth retaining.

Seems similar to the Kindle issue:

"What page are you on?"

"26%"



I think of how far (known places) are in terms of driving time. I can approximate that reasonably accurately ... I'll stop short of proposing a Travel-Time to SOC-Percent calculation

 

[GRiLLA]

Seems similar to the Kindle issue:

"What page are you on?"

"26%"



I think of how far (known places) are in terms of driving time. I can approximate that reasonably accurately ... I'll stop short of proposing a Travel-Time to SOC-Percent calculation

I'm not sure I've ever understood distance units, I measure in terms of time to get there as that's the only thing that would seem to matter to me. Who compares flights or train journeys in terms of miles rather than time.

 

[Adopado]

I had a BMW motorbike which had a bizarre way of quoting fuel level. It would show range until you got down to about 35 miles then just a warning to get fuel - no range quoted, but from that point it would begin to show the miles you have done since the warning, increasing as you went on. The fuel level was represented by 5 bars so when you were on the last one you really had no idea how far you had left if you hadn't been keeping count.

(And yes, it did catch me out more than once.)

Luxury ... a motorbike with a fuel gauge! Mine only pops a warning light on when low ... no other indications until it stops! I was caught out once but never since. There's no excuse really when you can take the cap off the tank and have a look ... coincidentally it has about the same "range" as an SR+. (Original Suzuki SV650S)