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

[JCtx]

If you can drive a steady 65 MPH, you should be able to do the 241 miles

I don't know if you'd do that yourself, but I'm using your example to say that I don't get that mentality. I get that some folks might want to minimize charging time, but the idea to drive 3-1/2 hours without even a bathroom stop, having to charge to 100%, and arriving with basically no range left (if nothing goes wrong, like a head wind, etc), is just utterly crazy to me. And it was proven above that you can drive as quick as you want, make 1 bathroom/break stop (let's say 15 min), and actually make less time, while driving more relaxed, alert, comfortable, and arriving with a decent safety margin.

I've never heard of people driving ICE cars gambling with the amount of fuel so they can get with as low reserve as possible; it makes no sense on an ICE or EV car. We knew right off the bat we'd have to spend more time charging than fueling when we bought the Tesla, but we'll never hyper-mile, or do crazy crap like that just to maximize the distance from supercharger to supercharger, when you don't even save time overall. But to each his own, I guess . We'll keep doing 150-mile legs when possible; it's nice to have a break by then, and the car is charged when done.

 

[MountainRatMat]

I don't know if you'd do that yourself, but I'm using your example to say that I don't get that mentality. I get that some folks might want to minimize charging time, but the idea to drive 3-1/2 hours without even a bathroom stop, having to charge to 100%, and arriving with basically no range left (if nothing goes wrong, like a head wind, etc), is just utterly crazy to me. And it was proven above that you can drive as quick as you want, make 1 bathroom/break stop (let's say 15 min), and actually make less time, while driving more relaxed, alert, comfortable, and arriving with a decent safety margin.

I've never heard of people driving ICE cars gambling with the amount of fuel so they can get with as low reserve as possible; it makes no sense on an ICE or EV car. We knew right off the bat we'd have to spend more time charging than fueling when we bought the Tesla, but we'll never hyper-mile, or do crazy crap like that just to maximize the distance from supercharger to supercharger, when you don't even save time overall. But to each his own, I guess . We'll keep doing 150-mile legs when possible; it's nice to have a break by then, and the car is charged when done.

I disagree with your 2nd paragraph. I try and keep my battery state as low as possible while still leaving a safety margin that I feel comfortable with. I usually aim for 15% SOC at a supercharger which always ends up lower and I don't feel comfortable going below 5%. Unlike an ICE car the "fuel" tank fills faster at lower SOC where as an ICE car doesn't fill gas any faster with an empty tank.

 

[KenC]

What terrible advice by ABRP on the route out to Vegas, you want to arrive at a Supercharger with a much lower state of charge to improve charge rate. Go to Baker, top up for 15 min then on to Vegas.

The route back home is much better, it is much faster to arrive at a Supercharger with a lower state of charge than high state of charge because the battery will charge faster that way.

Actually, that's exactly what ABRP recs for 80mph with 10% deg, starting at 100% SOC, a 12 to 15min stop in Baker.

 

[JCtx]

Unlike an ICE car the "fuel" tank fills faster at lower SOC where as an ICE car doesn't fill gas any faster with an empty tank.

It doesn't matter what the differences are; it's just unsafe and crazy to plan to arrive in reserve (either gas or electricity). And also to drive 3-1/2 hours without stopping. But to each his own. We just plan for whatever charging time is needed without slowing down, always having enough range in case of accidents, detours, delays, etc (and to keep HVAC on), and stopping/resting enough to drive safer. We're not going to get anywhere, so I'm out of here .

 

[Simavon]

“if the truck came to a sudden stop”

Curious minds inquire: Unless a loaded semi hits a wall, how does it come to a “sudden stop”?

Hits another stopped semi that was obscured from view because you were following too close to see. Or one that Tesla has failed in tests, vehicle in front swerves to reveal stationary vehicle it was about to hit.

Or maybe the semi drives over some debris, and then you have no time to react, and it destroys your battery tyres/wheels/bumper/battery.

 

[JCtx]

I'd never closely follow any kind of vehicle, let alone a semi, where you can't see crap ahead of it. Just the fact it'd pepper your car with road debris should be enough of a deterrent. But it'd be very dangerous too. Just schedule enough charging stops so you don't have to do any crap like that, and problem solved .

 

[Simavon]

Hits another stopped semi that was obscured from view because you were following too close to see. Or one that Tesla has failed in tests, vehicle in front swerves to reveal stationary vehicle it was about to hit.

Or maybe the semi drives over some debris, and then you have no time to react, and it destroys your battery tyres/wheels/bumper/battery.

i know I said battery twice. But it seems like an important point.

 

[MarcG]

I'd never closely follow any kind of vehicle, let alone a semi, where you can't see crap ahead of it. Just the fact it'd pepper your car with road debris should be enough of a deterrent. But it'd be very dangerous too. Just schedule enough charging stops so you don't have to do any crap like that, and problem solved .

I once drove on a long road trip heading west on I-80, and was in an area of Nevada with close to nothing between my last two supercharging stops (no towns, and certainly no EV chargers of any kind). At my second-to-last charging stop, I supercharged to the point where the Nav planner said I charged enough to reach the next and last SC, and the energy app showed I would arrive with 21% SoC remaining.

Unfortunately, that was way off due to decreasing temps (it was getting late at night) and quickly increasing winds. The estimator kept dropping down, down, down and ended up below 0%. I kept slowing down, down, down to about 50mph on a freeway where most other vehicles are going at least 70mph. Driving any slower would've been dangerous (in some states there's even a minimum freeway speed limit, not sure about NV).

The only choice I had was to draft a semi that was going ~60mph. After a few miles the energy app started readjusting and finally showed I would arrive at my next SC with over 0%. I arrived with 1 rated mile left on the dash.

I realize this is a unique situation, but it can happen and there may be no other choice than to draft. It's that, or get stranded in the middle of nowhere late at night. I still think I made the right choice.

 

[JCtx]

Oh man; talk about range anxiety. Ha ha. Glad you made it. And yes, there's another choice, and after reading your story, I'm glad we made it. And that is to charge enough to get with 30% range. On our first and only long trip so far, we arrived with about 20% once, due to a strong headwind, even though I had to slow down quite a bit from the 80 speed limit. And we were lucky we were going east, since there was an accident on the other side, which traffic backed miles and miles. And it was near freezing. I wouldn't want to be without HVAC in a case like that, so we'll continue to pursue that safety factor whenever possible in winter and summer (100F+ for months here). If no HVAC is needed, we could live with 25%.

 

[Rocky_H]

and the energy app showed I would arrive with 21% SoC remaining.
[...]
I arrived with 1 rated mile left on the dash.

Ah, yep, and this is why I get nervous with people saying they are going to leave with an estimate of 5 or 10% because "it's so accurate". I try to shoot for at least 20% or maybe 15% if it's like nice summer weather.
The other thing (and I'm not sure if you were doing this) is that I will usually start off staying noticeably within the speed limit or a little less for about the first 5-10 minutes to let it see and adjust to current outside conditions, like if there is a headwind and show the adjusted energy projection. It's a lot easier and less stressful to start off slowly and burn up extra range later if it's there, than to start off too fast for a while, find out you have a problem, and be trying to claw back extra range out of nothing later on.

 

[KenC]

I think of it this way. In all of my previous ICE vehicles, I would plan/budget so that I would refill with 2 gallons of gas left in the tank, but of course, sometimes, it could run lower to 1 gallon. My last ICE had a 16 gallon tank(BMW 330xi), so basically I planned to refuel at 12% SOT (state of tank), 2 gallons divided by 16, but ran as low as 1 gallon, so about 6% of my tank.

I don't see any reason to change the buffer for my Tesla, seeing as my last ICE was rated for 16/20mpg EPA, meaning that the 2 gallons gave me range of about 32 to 40 miles. In my Tesla, I plan for 15% SOC to refuel, and destination for 10%. That's approximately the same amount of miles available.

Yes, I know there are more gas stations than Superchargers. Yes, I know BEVs are more affected by temperature. Once, you get adapted, you make mental adjustments. It's no different than switching from a Prius to a Porsche, you have to adapt to the vehicle.

In my Tesla, if I'm going on a trip, I take a look at ABRP, and put in the best data possible, ie my speed, and coldest temps I expect. Then when I'm on the trip, I have ABRP open, and logging my car's real data, and updating whether the battery usage is going to plan. If not, I adjust. ABRP sees my real temp from the car's sensors, so it's updating the estimate all the time. The only significant variable impacting range that ABRP can't get from the car is windspeed and direction. I can look up windy.com to get a sense of the overall situation, but even if I don't, ABRP is constantly updating the live estimate. As far as I'm concerned, 15% SOC to get to a Supercharger is enough cushion, you just have to keep track of the dynamic situation and adapt accordingly. I don't want to run too low and cause any anxiety, but I also don't want to waste time charging when I don't have to. So far, in 2 years, I haven't ever had any anxious moments. YMMV.

Actually, I drive my BEV "3" exactly the same way I drove my ICE "3". I stop the same places for coffee, toilet and fuel. Trips take me the exact same amount of time. I've been going between Maine and Boston for 50 years, and believe me, it's the exact same time with the exact same stops, and I run the tank down to the same approximate levels, 12% to 15% SOC/SOT. It's the reason why I got the BEV "3" when I did, and not an "S", earlier.

 

[Grump99]

Just wanted to confirm what others here have been reporting.

We have a 2019 stealth performance with 21.5k miles on it. Our max stated range had been hanging around 288-291.

After the latest software update our range sudenly dropped to 277-280.

I wish that Tesla would be more transparent about whatever is going on with these updates. It's definitely frustrating.

 

[MarcG]

I’m starting to think the latest fw update changed the BMS to show less capacity when temps are colder to a greater extent.

Meaning, before 2021.48.35.5, the BMS would show a drop of a few miles of EPA-rated range when average temps dropped by a certain amount over a period of time, but with this update, the drop is larger (like 10-15 miles).

I noticed that my range dropped several miles after spending a couple of weeks in the mountains with near-freezing temps. But now I’m back in SF where temps have been unseasonably mild (thanks a lot, climate change..) and I’ve regained most of the lost range again.

This didn’t use to happen at nearly the same variance in prior updates. Thoughts from others who’ve experienced the range drop? Are you in regions with cold winters?

 

[Candleflame]

I wish that Tesla would be more transparent about whatever is going on with these updates. It's definitely frustrating.

yeah, thats sort of all we want....

 

[KenC]

I’m starting to think the latest fw update changed the BMS to show less capacity when temps are colder to a greater extent.

Meaning, before 2021.48.35.5, the BMS would show a drop of a few miles of EPA-rated range when average temps dropped by a certain amount over a period of time, but with this update, the drop is larger (like 10-15 miles).

I noticed that my range dropped several miles after spending a couple of weeks in the mountains with near-freezing temps. But now I’m back in SF where temps have been unseasonably mild (thanks a lot, climate change..) and I’ve regained most of the lost range again.

This didn’t use to happen at nearly the same variance in prior updates. Thoughts from others who’ve experienced the range drop? Are you in regions with cold winters?

Sounds like a reasonable possibility, but why wouldn't everyone's "3" do this after the 48.35.5 update? Mine doesn't, and I live in an area cold enough that I get a snowflake almost every day since my car lives outside. My estimated BMS has been the same as always.

 

[Candleflame]

It doesn't matter what the differences are; it's just unsafe and crazy to plan to arrive in reserve (either gas or electricity). A .

to you living in the USA with charging stations right left and center. This is not the case abroad where it can sometimes even get tight with petrol! I.e. at nighttime you sometimes have to cover 500-600km with petrol.

 

[JCtx]

I’m starting to think the latest fw update changed the BMS to show less capacity when temps are colder to a greater extent.

I wouldn't have a problem with that, as long as range is not actually decreased. But rather, just more realistic. Hope that's the case .

 

[MarcG]

I wouldn't have a problem with that, as long as range is not actually decreased. But rather, just more realistic. Hope that's the case .

Très à propos:

Tesla range estimates called into question in independent tests - Electrek

 

[Candleflame]

i find the rated range quite realistic. dont think about it as range, think about it as battery capacity.

 

[AlanSubie4Life]

I wouldn't have a problem with that, as long as range is not actually decreased. But rather, just more realistic. Hope that's the case .

It means that the BMS thinks that you actually have less energy available. The BMS is usually right, though obviously it can be right, and your energy can also come back later when it is warmer. Etc. Typically, it does not come back, though. Generally a downward trend as one would expect. Most people see 5-10% less energy after a couple years and 15-25k miles, but a few lucky ones see minimal change (@KenC is actually the only owner I know of who has not seen any significant range loss after a couple years).

There's not really any such thing as "more realistic," unless you mean it's better capturing the available energy when cold (which would be more realistic, and indicate you have less energy available for use on a full discharge when the battery is cold - which is largely supported by Tesla's cold weather EPA testing, FWIW - all these numbers are clearly published for all to see (search Charge Depleting 20F and compare to others): https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=51301&flag=1).