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Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health
- Thread starter KK_RedM3
- Start date
It's not so much that the batteries don't like it. It's just that the car has a lot higher energy use for various things when it's cold. People get a little fooled looking at the display and thinking that always = miles. But that's all of the energy the car has, so that has to = heat + miles.
There have been several threads with this discussion. If you are a person who always expects that number to equal your real distance miles traveled under all conditions, then sure, it will just be useless and frustrating and infuriating to you. So plenty of people don't want that annoyed feeling and switch to % to just not think about it. But driving distances don't relate to me in %, so that's kind of useless, so I prefer the rated miles. I just don't mind seeing that the number is always going to be higher than my real miles by some noticeable fudge factor. That doesn't bother me, so it's still useful.
AlanSubie4Life
Efficiency Obsessed Member
Awesome, that works great for many people.
Just keep in mind that with rated miles, they always represent a fixed amount of energy per rated mile displayed, so you can do things like the above. However, over the life of the vehicle, each % does NOT represent a fixed amount of energy per % displayed.
So over time, you will get a little less distance per % than you expect (reasonable to expect about 10% less (YMMV) after 3 years, so 2.25 miles, or 225 miles, rather than 250 miles, for 100%).
Whereas if you use rated miles, you will always have that same energy per rated mile, so assuming identical conditions to your baseline case, and no efficiency updates in software or hardware (like tires), you'll always get that same distance per rated mile of energy.
JCtx
Member
Oh yeah; I'm fully aware of that... but it's the same thing in energy or miles (range depends on a lot of variables). But thank you for mentioning it 
. It's an EV car, so we already got used to deal with energy %, rather than miles. The 2.5 miles per 1 percent is the worst case scenario, so I shouldn't have to adjust that in a while . Plus remember I shoot for 30% range, so no need to be precise at all. Ha ha.
. It's an EV car, so we already got used to deal with energy %, rather than miles. The 2.5 miles per 1 percent is the worst case scenario, so I shouldn't have to adjust that in a while . Plus remember I shoot for 30% range, so no need to be precise at all. Ha ha.I’ve had my model 3 since august 2020, I also have solar panels so with that I just thought I would be able to charge without much of an increase in my electric bill. My true up bill here in California has raised up triple than it was last year. I have now recently started charging only after 1am and when my battery has dropped closed to 20% left after about 5 days of use. My question is, will charging every night be a lot cheaper if I only use about 12-15% daily and charge it back to 80% and will it also harm the battery long term down the road? Thanks for your advice in advance.
Since you have solar there are some complicating factors so I can't tell you which way is cheaper, but as far as damage to the battery, absolutely not. If you are charging from 65% to 80% daily that would be about the most ideal cycle for long battery life that I can think of. Much better to do that than to let it get down to 20% before recharging.
My 2018 LR says 100% is ~280 miles, usually less. It was 270 or so, but after some deep cycles and time at 100% with no drain to cell balance, I got to high 270s, 280 on some lucky days.
Tesla says this is acceptable and in fact, I was charging too much. I need to let it drain lower before charging, only cycling 90 to 80 to 90% a day was throwing things off. My multiple cycles seems to say this is BS.
Worst of all, it suddenly happened in early 2020, just suddenly lost 30+ miles after an update. Losing over 10% in just over a year was a bit extreme, but at least it's stopped. Seems like it's just software based, but still frustrating. I know, turn it to % and don't look back...but when I travel, the car's GPS is calculating 280 miles max range on a good day, losing 30-60 minutes of extra driving between charge stops. That part bugs me.
Tesla says this is acceptable and in fact, I was charging too much. I need to let it drain lower before charging, only cycling 90 to 80 to 90% a day was throwing things off. My multiple cycles seems to say this is BS.
Worst of all, it suddenly happened in early 2020, just suddenly lost 30+ miles after an update. Losing over 10% in just over a year was a bit extreme, but at least it's stopped. Seems like it's just software based, but still frustrating. I know, turn it to % and don't look back...but when I travel, the car's GPS is calculating 280 miles max range on a good day, losing 30-60 minutes of extra driving between charge stops. That part bugs me.
Not buying Tesla’s answer.
Attachments
OK. Here's the range update I promised. Planned a drive from Austin to Columbus (end of Hwy 71 where it meets IH10) and back without stopping except to take photos of display. Vehicle was never in "park", only "hold" and only for a few seconds.. Had to wait until weather improved in Texas. Charged vehicle to 100%, awakened vehicle while still plugged in, range displayed 352 miles. T
Austin-Columbus: 95 miles, 28 kWh, 295 Wh/mile, 62% of power remaining, range showed 216 miles.. Drive is relatively flat. First 30 miles traveled 60-75 mph. Set cruise control to 80 mph for about 15 miles, then lowered to 75 mph for final 50 miles. Temperature outside was 55-65 degrees; internal temp in cabin was set to 69 degrees.
Columbus-Austin: 94.4 miles, 28 kWh, 292 Wh/mile, 24% power remaining, range showed 83 miles. Drove at speed limit (no cruise control) of 75 mph for 60 miles. Drove remaining 34.4 miles at posted speed limits of 60-75 mph. Temperature outside was 65-71 degrees; internal temp in cabin was set to 69 degrees.
Total trip was 189.4 miles, 56 kWh, 294 Wh/mile. Range decreased from 352 miles to 82 miles (270 miles), battery percent 100% - 24%. No Sentry Mode, no rapid acceleration at any time, vehicle never in Park. Total trip relatively flat.
Imputed total vehicle range is 249 miles (189.4 divided by 76% usage). Total battery charge displayable is 73.7 kWh (56 kWh divided by 76%).
This is for a 2021 Tesla Model 3 Long Range (refreshed model) less than 2 months old, 18" wheels, with no Sentry Mode on and no rapid acceleration. This is 70% of advertised EPA range.
I've asked Tesla to investigate what could have been done to increase range closer to EPA advertised range. I've done this twice before based on stop and start driving, and each time Tesla said nothing can be done the car is operating properly.
Range was a major factor in my purchase decision. At every step, Tesla reps told me range was achievable. Even websites like Teslike.com show older versions of the M3 LR getting 277 miles of range at 75 mph. This was for the 2019 M3 that had either 310 or 322 EPA range. I assumed my worst case scenario at 75 mph would be north of 300 miles, and likely closer to 320 miles of range. Not even close.
I frankly would not have purchased the vehicle had I any inkling real world range for a vehicle advertised to at 353 miles of range would be less than 250 miles of range when brand new. Let's see what Tesla says. I can post photos of the LCD screen at departure, at the end of the first 95 miles, and upon return to Austin. Total trip time was 2 hours 49 minutes.
If you want to achieve a range closer to the EPA advertised range you have to drive more like the EPA test. i.e. drive slower.
JCtx
Member
I was also disappointed at the huge difference between EPA rating, and real world highway driving, but I already knew that after my research. When we did our first (and only, so far) long trip, the car behaved just like I expected. At 80/85, in 35/60F ambient temps, and HVAC at 69/70, I averaged 2.5 miles per 1% charge, which equates to a theoretical range of 250 miles indeed. I settled stopping at each supercharger from El Paso to Austin, which are separated between 98 and 165 miles, to be able to arrive with 30% projected charge (for safety). The only leg I had to charge above 90% (to 95%) was between Junction and Austin (Domain area). The others required from 78 to 90% charge, and we didn't have to wait for the car except twice, and only for a few minutes. We were used to hardly stopping while traveling, but to be honest, I was happy to stop more on this car. I was more alert, and much less fatigued, so I really liked the 'forced' way to travel now. Ha ha. But I wouldn't do any more than 600 miles a day (it was 602 from door to door) on this car, due to the longer time to charge, and not liking to travel at night (for obvious reasons). All in all, happy with the car, but no way I'd have bought a car with any less range than this 2021 LR, since it's significantly less than advertised, especially on the highway.
Drive slower than the posted speed limit? Not a reasonable request of a normal consumer. If Tesla vehicles only achieve 70% of EPA range, this should be knowledge easily available to potential consumers. I spent 2 months researching Tesla M3, and range was a top issue for me just as it is for a significant segment of the market. That's why Tesla markets its range so heavily. Nowhere did I find that 70% of EPA range when new is acceptable performance for a brand new vehicle in almost perfect conditions. This is info that should be front and foremost in the public domain so potential consumers can make an informed decision. It is not currently, and needs to be better advertised. Not many companies will retain public trust by delivering 70% of what they advertise. Unless Tesla comes back and offers solutions, I will consider buying a Tesla a very large financial mistake.
JCtx
Member
I absolutely agree realistic highway range on EV cars should be required, rather than the misleading way EPA does on EV window stickers. Tesla only includes their fantasy 353 range on the window sticker, but no highway one. Misleading too. Anyway, if it wasn't for this forum, I'd have been sorely disappointed too, but I knew what I was getting into, so no regrets here.
I think overall vehicle performance is fine. But had I known range was so much lower than EPA, I would have waited until the technology improved. The Teslike.com shows a 2019 M3 LR with 310 EPA range achieving 277 miles of range at 75 mph, or 89%. With our 2021 M3 LR, that would be 315 miles of range at 75 mph. That's what I would have been fine with, not south of 250 miles of range or significantly poorer range performance from a vehicle marketed as having superior range.
But they deliver 100% of what they advertised; which is the EPA test suite range. You can't expect to get the EPA rated range when you aren't driving the same way as the EPA test suite. You can even get almost 200% of the advertised range if you try.
It sounds like you are more upset at the EPA. They make the test suite and the rules that that is the range car makers have to advertise. Tesla didn't make up those rules.
JCtx
Member
I think 55% to 70% would be even better . I read here that the ideal battery charge is 60%, but some say as low as 50%. Based on all the related threads I read, I decided to charge to 70%, and let it drop to around 50, before recharging again. Sometimes it's done in one day, sometimes in 5. With the possible crazy electric rates here in TX, I supercharged yesterday, from 45 to 85 (it's free all 2021). And might keep doing that until I receive this month's bill. Those 34kW (less than half capacity) could cost upwards of $300 in some parts of TX. Ouch!
. I read here that the ideal battery charge is 60%, but some say as low as 50%. Based on all the related threads I read, I decided to charge to 70%, and let it drop to around 50, before recharging again. Sometimes it's done in one day, sometimes in 5. With the possible crazy electric rates here in TX, I supercharged yesterday, from 45 to 85 (it's free all 2021). And might keep doing that until I receive this month's bill. Those 34kW (less than half capacity) could cost upwards of $300 in some parts of TX. Ouch!Here's a link to the LCD photos showing departure range, %, and at the end of each leg: 2021 M3 LR Austin-Columbus TX - Austin 2-21-21
I'm upset at Tesla. They put 353 miles of range at the forefront of their advertising, and in online chats with Tesla employees pre-sale they wrote 353 miles were achievable in normal driving. I could live with 89% of EPA (315 miles of range). 70% of advertised range, or not even 250 miles of range when new and in almost perfect conditions is not reasonable IMO.
Understand many here are happy with their Tesla vehicles and not concerned with my range issue. For most, buying a car is second only to a house purchase in importance and size. Many potential Tesla buyers rank range as a major pre-purchase issue. Range anxiety is an issue. Learning real world range of a vehicle advertised at 353 miles of range is only 250 miles when new and in almost perfect conditions may give many buyers pause.
AlanSubie4Life
Efficiency Obsessed Member
Yes, this all checks out and is normal. Note it is a different complaint from your first complaint:
Anyway, the math it looks like you have basically done already, but for full disclosure:
77.8kWh/353rmi = 220.4Wh/rmiEPA
95.5% is available from 353 to 0 mi (displayed) => 0.955rmiEPA/1rmi(displayed) * 220.4Wh/rmiEPA = 210.5Wh/rmi(displayed)
There's about 1% uncounted loss on the trip meter, so: 0.99Wh(trip)/1Wh(batt) = 210.5Wh(batt)/rmi * 0.99Wh(trip)/Wh(batt) = 208.5Wh(trip)/rmi
So plug into all above data:
95mi*295Wh/mi / 208.5Wh/rmi = 134.4 rated miles expected to be used (You used ~136).
Can't know for sure on Columbus-Austin, because we don't know what you started at, but it does look like it was close to 216 (and you said you didn't stop) EDIT: saw your pictures...close enough, though I don't see the ending miles (24% of 352 is 84.5 FWIW but it's coarse):
94.4mi*292Wh/mi/208.5Wh/rmi = 132 rated miles expected to be used (So you started at 83+132 = 215 rated miles - close to the 216 rated miles)
Obviously, since you seem to grasp the math here - you need to see 208.5Wh/mi on the trip meter if you want to get 353 miles of range (to 0%). (Note you have about 4.5% of your energy left when you get to 0%, but it's not advisable to use it!)
And as you say: these numbers imply you have ~73.6kWh (per the trip) available from 353 rated miles to 0 rated miles. That's correct, since that's 95.5% of your battery, so your battery has a capacity of ~77kWh. Remember that 1% loss on the trip meter - that'll take you to an actual battery capacity of 77.8kWh or so. Which is what a new car has.
So your car is GOLDEN. Again, key summary is 208.5Wh/mi for "parity." Everything else is direct 100% straightforward, trivial, ratio calculations from there.
A lot of people are surprised by the range, but it's really not something that should be that surprising, as long as research is done in advance (especially on this site). It's well known that you get ~200-250 miles for the first leg of a road trip, max, followed by ~150-200 miles for each subsequent leg, on an optimized trip.
I'm sorry that you were not aware of this before your purchase. The reality, I think you'll find, is that you spend very little time waiting on the car. I've done 1075 miles in a day, and spent less than about an hour actually waiting for the car to charge (my time at stops was spent eating, bathroom, etc. - each stop was usually just ~20 minutes, so that goes really fast!). Average speed including all stops was about 56mph. I kept the AC on. Much more of a problem than the range, honestly, is the availability of Superchargers that are open. (250kW Superchargers are also a key improvement which help a LOT - just be sure to arrive at 5-10% if you can do so safely.)
I think that trip was probably a maximum of about 1 to 1.5 hours slower than it would have been in a regular car (out of a total of a little under 19 hours).
I do NOT recommend you drive more slowly. I drove 70-85mph on my trip up I-5, and it was perfectly acceptable. You get to your destination fastest when you drive faster. If you drive more slowly you will end up traveling a slower average speed, including stops. I basically expect about 300Wh/mi at 80mph in ideal conditions, which on my car these days (my max range is now 285 miles, down by 8%) means a range of 233 miles to 0% (on my vehicle, 2018 3P+, 230Wh/mi gives me parity). Exactly what I expected when I purchased the vehicle.
The range expectation is more of a problem for people who do not have ready access to Superchargers on their chosen routes. Then it's an issue if you aren't anticipating it and you can't make the distance you need to make.
For stretching it, it's the obvious stuff:
1) Turn off climate control (or at least both AC & Heat)
2) Draft a solid vehicle traveling the speed you want, with mudflaps, at a following distance of 6 or 7 per AP, if you need to stretch to the next Supercharger. (Especially if there is a headwind!)
3) Inflate your tires to 43-45PSI cold
4) Drive in hot weather when the atmosphere is thin.
5) Keep your aero covers on.
6) No attachments to the vehicle allowed.
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