Hmm is possible the temp in your garage is warmer than the exterior temp when you were charging? I have woken up with a higher % than I went to sleep with but usually because I was out and about in very cold weather and my garage is relatively warmer. (Im actually thinking you may not have a garage since you are supercharging so close to your home. )
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Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health
- Thread starter KK_RedM3
- Start date
Like with any car the range constantly recalculates due to various conditions and available data.
Likewise cars never give you the exact published miles due ti the above.
Lastly Tesla is also doing updates to the range calculations as evidenced by recent firmware notes.
It’s always going to fluctuate.
Much like the stock market. You didn’t loose anything because the market went down one day. Well unless you sell while it’s down.
Likewise cars never give you the exact published miles due ti the above.
Lastly Tesla is also doing updates to the range calculations as evidenced by recent firmware notes.
It’s always going to fluctuate.
Much like the stock market. You didn’t loose anything because the market went down one day. Well unless you sell while it’s down.
I snuck over and gave you some charge during the night.
With people pulling up and steeling hundreds of gallons of gas while parked over the tanks using hidden hatches and pumps( I wonder at what point people are going to try and start steeling Tesla battery packs.
They’ve also been drilling peoples gas tanks and cutting out catalytic converters.
And, just to add to the fun:
The range numbers on the car are a complicated function of state of charge on individual battery cells, outside temperature, how long the car's been sitting still, not charging, since the last drive, and it goes on and on.
I'm driving a 2018 M3 LR RWD. Back when we got it, doing that (mileage at 90% charge/0.9) = max range was giving us around 320 miles. This dipped over the next year until it was showing around 290 miles. Then the spouse and I drove from NJ down to South Carolina and back, going down to 20 or 30 miles, charging it back up to 80% of full charge, and continuing on. After a day or so of this (range at %charge)/(%charge)=max range) number got up to - 340 miles!
Got back home, started driving normally, and, over the next month, it all drooped down to a max range of some 310 miles or so.
Was the battery really increasing/decreasing capacity? No way. There seems to be a number of reactions to this on the various forums:
Final point. If one has an ICE, the blame gas gauge might have that 1/4-1/2-3/4-full gauge, possibly with some extra markers. Nobody sane believes that that gas gauge, or the occasional ICE car computer that computes range based upon that gas gauge, is accurate. I've had many a car that, when it read "empty", had another gallon in the tank; and other cars that would read above full until the car had driven a hundred miles. Teslas, in general, are a lot more accurate than that, but you gotta figure it's not a-gonna be precise.
If you're really interested in how far you're going to get, use the Energy graph. It keeps better track.
The range numbers on the car are a complicated function of state of charge on individual battery cells, outside temperature, how long the car's been sitting still, not charging, since the last drive, and it goes on and on.
I'm driving a 2018 M3 LR RWD. Back when we got it, doing that (mileage at 90% charge/0.9) = max range was giving us around 320 miles. This dipped over the next year until it was showing around 290 miles. Then the spouse and I drove from NJ down to South Carolina and back, going down to 20 or 30 miles, charging it back up to 80% of full charge, and continuing on. After a day or so of this (range at %charge)/(%charge)=max range) number got up to - 340 miles!
Got back home, started driving normally, and, over the next month, it all drooped down to a max range of some 310 miles or so.
Was the battery really increasing/decreasing capacity? No way. There seems to be a number of reactions to this on the various forums:
- People do funky trips, sometimes several, running the car down to low State of Charge and back up again, with the occasional, non-guaranteed result that their mileage numbers will increase. Sometime it woiks, sometimes it doesn't woik.
- People stop looking at the mileage number and switch over to percentage. The percentage number doesn't vary as much, so it cuts down on ulcers a bit. But.. It still does vary at semi-random.
- Occasionally, people go ky-yoodleing off to Tesla to complain. One gets the distinct impression from reports that the Tesla people are so dead tired of this that they react to any range reduction complaint with the phrase, "The car is working normally." Unfortunately, as with any bit of hardware, now and then somebody has a car whose battery/mileage/what-have-you really is on the fritz, in which case they have to batter their way past the initial reactions over at the Service Center.
Final point. If one has an ICE, the blame gas gauge might have that 1/4-1/2-3/4-full gauge, possibly with some extra markers. Nobody sane believes that that gas gauge, or the occasional ICE car computer that computes range based upon that gas gauge, is accurate. I've had many a car that, when it read "empty", had another gallon in the tank; and other cars that would read above full until the car had driven a hundred miles. Teslas, in general, are a lot more accurate than that, but you gotta figure it's not a-gonna be precise.
If you're really interested in how far you're going to get, use the Energy graph. It keeps better track.
Candleflame
Active Member
there is some truth that that. Thats why i think Model 3 and Model 3 Touring is probably a better term rather than SR+ and LR.
With 15% degradation after 50k kms is probably gonna be similar but the Touring 3 would have awd and faster dc charging.
That is not correct. That is a very common forum truth but not correct. The research show us how things really work. Most research draw the correct conclusions, but there are some resesrch reports that show the correct values but they draw faulty conclusions(most often because the test setup was not very good).
If we start with LFP, modern LFP are not sensitive to the depth of discharge and will do very many full cycles(charge to 100% and discharge to 0%). For a car with shorter range that need to use a higher deopth of discharge(DoD), the LFP is a good choise. They use more space and is heavier so its not possible to use LFP in a long range car.
For NCA and NMC, they are affected by the depth of discharge. They also are affected by the SOC where the cycle is placed.
The lower the cycle is placed, the less wear.
This means using a 10% cycle causes least wear at 10% to 0%.
Also, the smaller the cycle(DoD), the less is the wear.
One research report used NCA and cycled the batteries 10% DoD around both 30% (35-25%) and 70%(75-65%). The number of cycles was 6000, which is 600 Equivalent Full Cycles).
The cells cycled around 70% lost 10% capacity.
The cells cycled around 30% lost 2.5% capacity.
This is from one research report, LMO/NMC cells. The reason I select these pictures is that it is easy to se the connection between DoD and wear. It should be clear that low SOC is the best. Its also clear that large cycles wear much more.
No, that is not right. Where do you find a recommendation to store at 50%?
The lower the SOC, the lower the wear for long time storage.
This picture show the long term effects of storage, High SOC and or High temperature is worse. The lowest degradation happens at very low SOC. There is a lot of research showing the same. There are no real exceptions from this picture.
High quality chargers for lithium batteries (like for hobby use of lithium batteries) have a storage function that charges or discharges the battery to a specific voltage. This is around 50%. But the selected value is chosen to both allow for long time storage and self discharge and also to reduce the time to chsrge the battery to 100% before use. That storage level is not set to reduce the degradation to the lowest level. But it is below the clear step we see in calendar aging around 55 to 70% depending on the chemistry type.
You only need to select what range you need. Tesla have already made the choise for you.
-Shorter range need large cycles(bid DoD) and there LFP is better.
-Longer range is not possible with LFP( these cannot be fitted into a model 3 because of the limited space). NCA (and NMC in Europe) is the only option.
Calendar aging cause the biggest degradation with both NCA, NMC and LFP.
If you would like to reduce the Calendar aging it is possible by having the SOC low when the SOC do nit need to be high.
Charge shortly before the trip, and leave it with low SOC overnight until the charging need to be started.
The cars battery computer(BMS) use two ways to calculate SOC.New Tesla owner here. I took delivery of my M3LR in January. I have been to a super charger twice prior to this. The two times before, I charged to 90% and that was equivalent of 322 mi. Last night I stopped off at a super charger. I charged to 90% based on the notification. I live like 2 miles from a super charging station so when I left I noticed that I had 318 mi of range. I thought super strange that my range dropped. Then I woke up this morning and started my car. To my surprise it shows that I had 92% range with 329 miles. Ummm what? I'm pretty sure I'm not mistaken. Has this happened to anyone and is it normal?
The best way(show correct value) is to read the open contactor voltage(OCV), when the car sleeps and the big battery is disconnected from the load. With no load the battery voltage is higher and it takes a little time to reach the true OCV. This ca not be done during a drive or when the car is awake.
The other way is to calculate the SOC from the currently estimated SOC and calculate the new SOC. For example, you arrive at the Supercharger with estimated 20%(not true as the car isnt sleeping), and then add 35kWh. If the estimated capacity is 70kWh, 35% SOC equals 50% added.
New estimated SOC = 20 + 50 = 70%.
If you park the car and it then sleeps( OCV available) the car take the voltage reading and compare with a reference. This will be the new SOC and might cause the SOC to change slightly on the screen.
It is not uncommon for the SOC to increase after a drive (from the SOC read at parking until next drive).
The reason for the shift can be a few different. If the BMS have a little different judgement of the battery capacity than the real capacity there will be a shift. Is using 35 kWh from a 70kWh judged capacity it is 50% discharge, but if the real capacity is 68kWh, 35kWh will be 51.5% of true SOC used.
The OCV shows the true SOC.
Thanks a lot for these graphs! I think they answer my question nicely, at least for the first 9.1 months.
An interesting detail for LFP batteries is that there is a plateau between SoC 40% and 70%, i.e. I'm not gaining anything by lowering the SoC from 70% to 40%. I would have to put the SoC even lower to gain longevity. So 70% looks like a sweet spot, if this level of degradation can be tolerated.
However, if the same degradation speed holds for longer periods, we may have to forget about 20 years. The hope is that degradation slows in subsequent years, which has indeed been reported from non-LFP cells.
Steve446
Dusty Crophopper, M3 LR 2021 Midnight Silver
@AAKEE - From the discussion, I understood that small DOD and small charges were best for NCA/NMC. What about the frequency of small charges? I don't use my car that much at present so I store @ low SoC (average 25-40%). When I want to use the car, I bring the SoC up to the kWh I will need for my return journey, 50% as an example. If the car is sitting at @ 20%, I'm reading here that I should bring it up in several, ~10% charges to the 50% that I would need for the trip.
My question is, how long should I wait between these successive small charges and, is that necessary? I had wondered whether 1) there was some physical-chemical "cooling off" period needed to avoid stressing the battery and 2) that it was BMS friendly to do that. For now, battery % by BMS only becomes a rough guide. For longer trips, I don't care too much about the BMS day to day range values since I measure kWh in the battery by SMT and calculate required energy for my trip from that based on known Wh consumptions for a specific type of drive. When I have a better feel for the car's Wh consumption I guess that I can leave range estimates to the car since it seems to do that quite well. I realize that not everybody has the time or desire to do that but since I'm retired I can focus on longevity for me and the car
My question is, how long should I wait between these successive small charges and, is that necessary? I had wondered whether 1) there was some physical-chemical "cooling off" period needed to avoid stressing the battery and 2) that it was BMS friendly to do that. For now, battery % by BMS only becomes a rough guide. For longer trips, I don't care too much about the BMS day to day range values since I measure kWh in the battery by SMT and calculate required energy for my trip from that based on known Wh consumptions for a specific type of drive. When I have a better feel for the car's Wh consumption I guess that I can leave range estimates to the car since it seems to do that quite well. I realize that not everybody has the time or desire to do that but since I'm retired I can focus on longevity for me and the car
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Calendar aging is described as reduced with the square root of time, as per the calculations I made.
If one year causes 5%, then it will take four years(another three) to double this. 5 x square root of 4 = 10.
I havent found any research reports showing more then 1-2 years or maximum 30 months. If anyone try to research the 10 year degradation the batteries would be obsolete and the new technology would have replaced those old steam batteries.
But the research show square root of time behaviour, or very close to this so we can use this to calculate a approximate degradation over long time. The result wont be exact down to the tenth of a percent but the reason for this will mostly come from our own assumptions about average cell temperature, average SOC etc.
- We can use it and get quite good prognoses but the biggest fault source will be our own assumptions.
If you set 25% calendar aging as the reasonable maximum limit for 20 years, youll find 5% is the maximum level for the first year. Then just see to that you do not go above the 5% line the first year.
(There is a caviat about that the latest LFP or any chemistry might be better or worse than the ones used in research. We cannot have research reports about the latest technology cells calendar aging before about two years after they are introduced( research need to get the hand on them and test for at least one year, then produce the report)
No, I would not say that youre helped buy charging in small steps. The cycle will still be from 20 to 50% regardless if you charged in three different steps. Charging from 20-50% in one charge or charging in tre 10% steps cause the same wear.
The term is depth of discharge, so you can focus on the discharge part.
Think of the battery as a balloon. The more you inflate it the more strain it get. The longer you leave it inflated the more sloppy it gets after the air is released.
cycles - DoD = the difference between the lowest and highest SOC during one cycle.
One cycle is from starting to charge via a end of charge SOC down to the point before the next charge.
Steve446
Dusty Crophopper, M3 LR 2021 Midnight Silver
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?
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?
ucmndd
Well-Known Member
No, it’s not a fair way to measure. No, it doesn’t seem low. No, it’s not worth investigating further.
The ~5000 page post pinned at the top of this section is a good place to start reading about range loss and efficiency.
The ~5000 page post pinned at the top of this section is a good place to start reading about range loss and efficiency.
No, that is not right. Where do you find a recommendation to store at 50%?
The lower the SOC, the lower the wear for long time storage.
This picture show the long term effects of storage, High SOC and or High temperature is worse. The lowest degradation happens at very low SOC. There is a lot of research showing the same. There are no real exceptions from this picture.
When I read that graph, take the first box for instance, it tells me that after 55'ish% the degradation starts kicking in much higher.
Unfortunately Tesla hasn't made my decision for me. Both models fit my range requirements, cheaper is not always better, I'm looking for the model that has the best chance at maintaining usable range for the longest amount time. That's why I've been trying to understand the differences between LFP/NCA. It would be good to know if Tesla just put a cheaper battery in there to solve supply issues and make more money, or is there any real potential benefit to me as a consumer.
Tam
Well-Known Member
If you want to be fair, please don't drive your car on actual roads. You need to have your car stationary in a controlled lab with its wheels on a dynometer.
No, not a fair way to calculate, no you should not investigate further if the "investigate further" is because you think something is wrong (it isnt).
Your thread was moved into this thread (the one that @ucmndd mentioned) because in the model 3 subforum, all range questions go here, and the vast majority of these 4000+ threads are some variation of that same question you are asking.
To save you from trying to read this thread (which isnt the intention any longer, although it works well to search this thread using the search tool to get information out of it), as was said, no its not a problem, no you cant calculate it that way, 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.
Well the selection of when a LFP is best suitable and when a NCA is needed is made by Tesla, so you only need to do the choise of a SR being goig enough or if you need a LR.
From the very small data available it seems like the LFP loos slightly less range initially than the NCA does.
As LFP should loose very little from the cycles its probable that most of the loss we see comes from calendar aging.
I would make guess that you can count with about half the degradation per year on the LFP compared to the NCA. Not very sure data but you can compare NCA and LFP loss per km driven on teslalogger.de check degradation and select M3 LR and compare to M3 SR LFP. There are a few glitches with non LFP cars which you can see on the range ( for example 500km range is not LFP or even a SR) so you need to adjust the aberage etc for this.
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