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Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health
- Thread starter KK_RedM3
- Start date
You can't without some sort of third party integration with your wall charger to stop charging. Maybe if you always leave at a certain time, you could set up a departure time that is well past when you normally leave. But that's finicky.
Just charge to 50% and don't worry about it. Or let the SOC get lower before you plug back in.
As I and others have posted - ideal is to charge to 50% if you don't need more than 50%, then recharge as needed. But honestly, charging to 70-80% or even 90% and then just recharging when you get down to 20-30% is probably just fine, too, since the average SOC will be lower than charging every day to 70-80% and calendar-life loss seems to dominate over cycle-life capacity loss.
Depending on your climate (Oregon is pretty cool in general), it may not make a big difference in the end. Heat accelerates the rate of capacity loss thanks to Arrhenious' equation where appx every 10C rise in temperature doubles the rate of chemical reaction. So it's more important to maintain a low average SOC in hot climates than cool/cold climates.
Candleflame
Active Member
I have a ChargePoint Home Flex charger. I just checked the app and it lets me set a start and end time, so I imagine I can simply do that to charge from 30% to 40% whenever I want!
You're going to have to elaborate - it's very hard to count cycles on an EV - a 10% depth of discharge cycle is not the the same as a 100% depth of discharge cycle.
If I recall, you have quite a bit more capacity loss than most - this is almost certainly due to your climate. It's pretty warm in Queensland and could be pretty warm where you are specifically. As I mentioned, Arrhenious' equation means that a 10C increase in temperature will appx double the rate of capacity loss.
In Oregon which it's typically quite cool comparatively - charging habits matter a lot less. The coolest month in Cairns is about has hot as it gets in Portland, for example, looking at average high / low temps.
Candleflame
Active Member
1 cycle is one 100% discharge i. E. 2x 50%.
As i said over 150 cycles at less than 48k kms is very significant and almost certainly more so than calender aging regardless of ambient temperature. In cold climates calender aging is even less significant and cycling is and remains the most important contributor to range loss.
No - two 50% depth of discharge cycles is not the same as one 100% discharge.
I disagree - there's a lot of high mileage Model 3s out there with very similar amounts of capacity loss when compared to lower mileage Model 3s of the same age.
Or similarly, KenC who posted up above is still reporting basically 100% capacity after 3 years / 31k miles. On the other hand, you are reporting 16% capacity loss with the same number of miles. Similar number of "cycles" due to driving, but obviously your car spent most of it's life at 30C while KenC's car has spent most of it's life at probably 10C on average - maybe less. Now it's impossible that KenC actually has 0% capacity loss, but low-mid single-digit capacity loss is likely.
The difference between the two cars is calendar aging influenced by temperature - not cycling.
Well, I think you two speak beside each other.
In the battery world the norm is Equivalent Full cycles (EFC). We should use this term as even if a small cycle wear lot less than a full 100 to 0%, you need many more small cycles during a cars life(or one year of driving).
Two 50% cycles is 1 EFC. one 100% cycle is one EFC. But they do not cause the same wear, and this is important. If we do 3500km in one year we problably need about 100 EFC. We could do it with one hundred 100 to 0 cycles but this would eat a large piece of the battery. We would probably loose 10 or 15% in one year for the cycling only. If we instead use 1000 10% cycles we can drive the same amount of miles, but the wear will be way less.
Scan My Tesla calculates charge cycles and discharge cycles. By this they mean about the same as EFC. They use the total number of kWh charged, and split it by the current nominal full pack.
By definition one EFC is the amount of energy charged / the new battery capacity*, so the SMT number isnt the same thing, but close. It should be divided by the capacity of the new battery, or specified size.
I actually think the real definition it the total thoughput(charge+discharge) / the new capacity x 2 but to make it easy we can stick to the above definition.
No, this would use energy so it would most probably need a higher SOC which is bad. Even if you have the car connected to the charger and not care about the energy consumption, it not clear how it would affect the battery temp in very hot weather.
Just by leaving the car with 20-30% SOC instead of 60% or more in a hot climate(or cold climate) you have at least cut the calendar in half. I have a hard time seeing that any other action would help as much as this.
I had my car inside my insulated garage during the warmest day when I was home, and this probably lowered the battery temp quite much, on average 20C instead of at least 30C, probably 40C the hottest days.
Yes. 100% correct.
We have a guy on a swedish forum driving quite much with big cycles(250km each work day). Hes car is the same as mine, but slightly newer. About 9 months now, and 60.000km. He have lost about 6% capacity according to the BMS*. He drives from 90% to 7-19% each work day,
So, even with about 80% EFC Cycles he only loose about 1% per 10.000km.
We know that a small cycle cost very little even when we count in EFC, so big cycles eat much more.
( the example is the research report of NCA battery cycling where a 600EFC with 10% cycle around 30% only did wear 2% but 600EFC around 70% did wear 10%).
No one that use much smaller cycles than that swede's 90% to about 10% on a daily basis will wear more than 1% per 10.000km (= 2% per 20.000km or 1.6% per 10.000mi). A annual driving of 10.000km/mi or 20.000km will not wear more than 2% for the cycling, probably much less as the cycles will be smaller for most people driving short trips.
For the calendar aging part, it is not possbile that a battery cell type that is proved to degrade from calendar aging for example 5% during the first year at 20C at 50% SOC to have a much smaller calendar aging when put in a car if the conditions are the same.
*) He arrives at home with 7-19% and then the car sleeps at that low SOC until it need to be charged to be ready for the next days trip. Exemplary sorted, and that car's calendar aging will be very low. What we is for the absolute most part = cyclic aging.
After 5 days of my model 3 being parked outside, the battery has drained about 130 miles. I live in NorCal, and although it has been a little colder this week (30-60 deg F), it shocks me that it drained that much! I do have sentry mode on, no energy saving settings on, and opened the app twice. I am sure sentry mode plays a role in the draining and will turn it off, but after reading some other posts, I have yet to see anyone experience this magnitude of battery drain from sentry mode. Has anyone had this experience or know any other factors could be contributing to this amount of drainage?
(Purchased this car in July 2021 if that is useful information)
(Purchased this car in July 2021 if that is useful information)
Thats it right there.
Not sure where you read, Since you say "I have yet to see anyone say they experience this" (because everyone experiences it with sentry mode on) but yes, everyone who has sentry mode on experiences around that level of drain (20-30 miles per 24 hour period).
I can see where it would get lost. There's only one thread per two or three days saying almost exactly what you have, and they get shuffled into this 201 page thread very quickly
Hi All,
My 2021 M3 range has dropped from 262 @ 100% to 238, within 5 months of ownership. I did have a previous Model 3 that never saw this kind of drop off in the 1 year I owned it. I don't drive with a lead foot, I only charge to 85%(charged to 100% once right before a road trip) and I plug in nightly at home with level II. Would you consider this normal and nothing of concern? I did schedule a mobile visit regarding range as well.
My 2021 M3 range has dropped from 262 @ 100% to 238, within 5 months of ownership. I did have a previous Model 3 that never saw this kind of drop off in the 1 year I owned it. I don't drive with a lead foot, I only charge to 85%(charged to 100% once right before a road trip) and I plug in nightly at home with level II. Would you consider this normal and nothing of concern? I did schedule a mobile visit regarding range as well.
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You might as well cancel that appointment, unless or until you reach the 70% thresshold (which for a car that started with 262 range would be a reported range in the car of 184. Tesla is going to cancel it for you anyway, actually, and tell you some combination of "its normal / Its winter / the car will tell you if there is a problem".
So they asked me for more info, I provided them the same screenshots and they ended it with "we will review, it's queued up for a tech" today.
I left my car at the airport for 8 days, and lost 100 miles of range, in the frigid cold. I had my Sentry on about 2/3rd the time, basically, at night. It's possible to lose up to 1.4miles of range per hour with Sentry on. Your 26miles of range lost per day, is well within what's possible.
AlanSubie4Life
Efficiency Obsessed Member
If it was a 2018 or 2019 (hard to know with the timeline here), then that's because a portion of the losses in those vehicles is hidden from view (degradation threshold is substantially below nominal full pack when new). Not so much the case in your SR+.
Also there's probably some vehicle-to-vehicle variation in how the BMS behaves and how the battery behaves. You may have just had a "good" pack in the prior vehicle.
But in any case 10% capacity loss (could be as little as 7% depending on BMS errors, extrapolation errors, etc.) is fine & quite common after 5 months.
If you don't need the daily range, lower your daily threshold to 50-60% (best bet for reducing capacity loss). If you need the range, or that's too restrictive/stressful, just leave it at 85% and don't worry about it; it doesn't really matter, it will be fine.
Best to just forget about it and acknowledge that it represents real capacity loss, which will impact your range between Superchargers.
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