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First World Problems: Display Range or Battery % but not both....?
- Thread starter Benjanos
- Start date
Hugh Mannity
Mediocre Member
so for you percentage guys how do you determine how much you have left ? For my family if we are around town only we tend to charge the car once every 3 to 4 days - If it's Day 3 I have no idea what it means to have 30% left if I need to run some errands, visit my sister and dick around with some other stuff. However if my display shows me 100 km left I know I have lots left to do those errands and end up with 20 km+ ish left when I get home. I'm curious how you know you are good ?? It sounds like you don't do the percentage to mileage conversion in your head - that would after all defeat the purpose of using the % setting at all.
bishoppeak
Member
I just charge every night and mostly use the percentage on longer trips where I'm stopping at superchargers. Set the nav for the next supercharger, charge until it's 10-15% on arrival and be on my way.
Ruffles
Member
Brass Guy
Active Member
This seems to me the only logical argument for %.
A question about nav since I don't have it: if you're set to miles instead, does nav still report remaining range in %? I would expect the answer to be "no, in miles" but this is Tesla interface so I will not assume.
bishoppeak
Member
Excellent Question! Got me to go down to the garage and check, it stays in %
Brass Guy
Active Member
Thanks for that...
So if instead it showed miles, it'd be just as easy for anyone to use distance; but Tesla's nav kinda forces you to use % setting if you want to keep an eye on remaining range, which you should during a trip. Another easy software fix.
I'd like the IC to show both % and miles, but currently showing % makes the most sense to me. The actual distance traveled is absolute and would never change, but the amount of energy required to travel that distance is variable. I don't always have an idea how many miles it is to a certain location, but using nav, it shows me exactly how much percentage it'll take to get somewhere and even the return.
My rationale is this: say I'm going somewhere that's exactly 100 miles. Round trip it's 200 miles and with my 250 miles of range, I should be good right? However, that doesn't take into consideration elevation, weather, etc. With % I'll know it's say 45% to go there (uphill), and 35% return (downhill). Then if it's super cold or strong headwind or I'm towing something, I'll know to add a factor so then it may be 65% to go there, and 50% return. This tells me I have to charge halfway. This is much easier than thinking about how it'll take 147 miles of range to drive 100 miles.
Every once in a while when I do need to charge to nearly 100%, I'll switch the units to miles just to see how my estimated range is degrading (I'm only seeing a loss of ~4% over 12K miles).
My rationale is this: say I'm going somewhere that's exactly 100 miles. Round trip it's 200 miles and with my 250 miles of range, I should be good right? However, that doesn't take into consideration elevation, weather, etc. With % I'll know it's say 45% to go there (uphill), and 35% return (downhill). Then if it's super cold or strong headwind or I'm towing something, I'll know to add a factor so then it may be 65% to go there, and 50% return. This tells me I have to charge halfway. This is much easier than thinking about how it'll take 147 miles of range to drive 100 miles.
Every once in a while when I do need to charge to nearly 100%, I'll switch the units to miles just to see how my estimated range is degrading (I'm only seeing a loss of ~4% over 12K miles).
I'm a range guy but for different reasons. I acknowledge that the range number displayed will jump around a lot and 1 mile of range display does NOT equal 1 mile driven. I know that the number of miles I can actually drive is generally something LESS than the range number displayed UNLESS I am doing extended highway driving (where the car ends up being quite efficient and my Watt Hours/Mile runs better than the rated number. The reason I use range is because I charge my car every night to 60%. If the range number displayed in the morning is different, I have information that something changed and or some indication of battery degradation (same reason I charge to 100% every once in a while to see how much my battery has degraded. I believe that, even with a degraded battery that has lost range, if you charge to a given percentage (say 100%), the display will still indicate 100% and you don't know you have degradation...but that if you display range, you will actually see a lower number of miles. Can any longtime owners confirm my theory is correct?
I charge the car every time I drive it, so it ends every day at 90%. On the road would be a bit different depending on whether charging is available overnight, but that's rare.
I also display the trip odometer stuff in the instrument display so I monitor how efficient I'm being by mentally adding the miles driven to the miles remaining.
The battery icon display gives you an approximate percentage along with the range remaining if you set it to display range. The colored bar shrinks as the battery runs down. It's not perfect, but it's as close to both as you can get now.
I also wish there was an option to display all distances and ranges with the first digit after the decimal. In the trip odometer you get 1/10th miles (of Kms I assume) and you also get it in navigation, but all the other range and distance displays round off to whole numbers. I know most people would prefer whole numbers, but I would prefer all displays to have the extra digit. The car knows it, it just isn't displayed.
mspohr
Well-Known Member
Old gas cars had a (very inaccurate) needle gauge so mostly just bought gas when it got low.
New gas cars give a range in miles/km but not %.
One of the benefits of charging every night is not needing to worry about range. I plug in every night, but could go a few days without charging. If I missed a night, then it's no big deal. It came with experience that I can make a round trip in the region without needing to know how many miles I would need. I don't even keep track of miles to places so seeing the miles range wouldn't help me. It would be like X miles range minus unknown miles to destination = who cares? I don't. When I go somewhere out of my region, I would use A Better Routeplanner to plan the trip and charge to full, and let the Tesla Nav let me know if I have enough. It even calculates the percent battery remaining after doing a round trip before I even start the trip. I tend to get a higher percent remaining than the Nav predicted if the trip is a long one. Also, being in the Bay Area, I have lots of Supercharger options, which I haven't had to use while traveling within it.
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I believe you mean imprecise, not inaccurate. The concepts of precision and accuracy are often colloquially mixed, but are distinct...and the distinction is important. Precision is the specificity of a measurement; accuracy is how close a measurement is to the expected/actual value.
Why is this distinction important? Because the fuel gauge in pretty much every gasoline powered vehicle ever made has been a percentage display, just not a particularly precise one. The concept of reading a percentage display is decades old. Mind you, that's not an argument for (or against) percentage display - it is a rebuke of the contention that percentage display is new/unfamiliar.
Which gasoline vehicles exclusively display current fuel level in terms of distance?
They pretty much all do the same as Tesla (when selected to show miles), a pictorial graph showing how full and a number showing miles left. I’ve never seen an ICE display a %.
Tesla would be pretty much identical to ICE if it just tweaked the software to display range left in miles based on recent consumption.
This is a common misconception/misunderstanding of what a fuel gauge displays, which is why I described the difference between precision and accuracy.
The ubiquitous "[E----F]" sort of gauge is a percentage display. Perhaps it makes more sense to think of them both as a fractional display. People have been reading such displays for decades in quarters, eighths, or even sixteenths. Tesla provides a fractional display in hundredths. The difference is only a matter of precision.
Brass Guy
Active Member
I see what you're getting at, @Mediocrates - but "percent" literally indicates describing 100ths; while someone may say "I gotta get gas, I'm down to a quarter tank," it's not likely they'd say "... I'm down to 25%." I've only seen (edit) larger fractions on fuel gauges as you pointed out.
This introduces another point though; does the gauge need that much precision? With an ICE not really since the infrastructure is so fleshed out. With EVs it's not quite so convenient so more accuracy is warranted.
However with current battery tech, we've seen some drive past 0% (or 0 miles) and some shut down before 0; so our gauges are not really accurate down to the 100th either.
This introduces another point though; does the gauge need that much precision? With an ICE not really since the infrastructure is so fleshed out. With EVs it's not quite so convenient so more accuracy is warranted.
However with current battery tech, we've seen some drive past 0% (or 0 miles) and some shut down before 0; so our gauges are not really accurate down to the 100th either.
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I was thinking about why miles information is not useful to me. I realized it was because with crazy Bay Area traffic and road design, the fastest and/or most pleasant route isn't the shortest one. This makes it not worth it to me to remember how far away places are but figure roughly, like a gas gauge, how long it would take to get there, and the optimal route could vary based on traffic conditions, time of day and/or day of the week.
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mspohr
Well-Known Member
No, I did mean inaccurate. Every gas gauge I have owned has had significant nonlinearity. Inaccurate.
Every new car i have seen shows miles. None show percent.
