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Model 3 Performance - charged to 100% shows 293 miles range. Why?
- Thread starter LakeForestM3
- Start date
AlanSubie4Life
Efficiency Obsessed Member
I take this back. Not actually true. This is only true at 100% SoC. The easy way to tell this is wrong: this product goes to zero at 0% SoC (but at that point you'll still have the buffer energy remaining!)
In other words, correcting the above: The product of the graph numbers is the Full Battery Capacity * SoC%
Again, this is NOT the same as the remaining battery energy including the buffer; breaking it out as follows makes it clear:
FullkWh * SoC% = (FullkWh - BufferkWh)*SoC% + (BufferkWh*SoC%) = Wh/mi Avg * Projected Range
Whereas, due to the definition of SoC % = (RemainkWh-BufferkWh)/(FullkWh-BufferkWh), solving for RemainkWh, the actual remaining battery energy (as read by the CAN reader) is:
RemainkWh = (FullkWh-BufferkWh)*SoC% + BufferkWh
(Note it's the same formula, except for the BufferkWh scaled by the SoC%...)
Sometimes I think Tesla made this confusing, deliberately.
Maybe we just have the wrong way of thinking about it (even though the formulas are right), so things look confusing. I get this wrong from time to time, as do others. Sorry for the confusion.Aside, this is why rated miles (when referenced to the BMS "discharge" constant) click off at the rate of ChargeConst*(1-BufferkWh/FullkWh) per rated mile.
The last formula is:
RemainkWh = (FullkWh-BufferkWh)*RemainMiles/FullMiles + BufferkWh
The slope (in kWh/rated mile) is:
(FullkWh-BufferkWh)/FullMiles = (FullkWh-BufferkWh)/(FullkWh/ChargeConst) = (1-BufferkWh/FullkWh)*ChargeConst
It's rated miles. I use this whenever I'm talking about the miles on the battery gauge, because it keeps the units straight (they aren't miles as units of distance). I use mi whenever I'm talking about actual miles traveled.
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I m starting to wonder if the range changes throughout the day based on temperature alone. Yesterday it indicated a max charge of 305 miles in the app, today 309. I haven’t driven the car. The range seems to change a bit based on some other variables. This battery stuff is complicated, we will be posting about this crap for years to come.
I think a variance like that of about 1% on the car’s range estimate is completely acceptable. Plus, you make no mention of how you are calculating. Did you charge to 100 both times and measure immediately after completion? Or are you charging to a lesser number and extrapolating? Regardless, it is tiny and not worth worry.I m starting to wonder if the range changes throughout the day based on temperature alone. Yesterday it indicated a max charge of 305 miles in the app, today 309. I haven’t driven the car. The range seems to change a bit based on some other variables. This battery stuff is complicated, we will be posting about this crap for years to come.
Msjulie
Active Member
My July build 2018 shows 258 miles at 90% 20,900 k miles (Performance AWD but OEM 19 rims and the car knows that).
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AlanSubie4Life
Efficiency Obsessed Member
I m starting to wonder if the range changes throughout the day based on temperature alone. Yesterday it indicated a max charge of 305 miles in the app, today 309. I haven’t driven the car. The range seems to change a bit based on some other variables. This battery stuff is complicated, we will be posting about this crap for years to come.
Yes, pack temperature (not ambient) immediately affects available energy and thus rated miles (I don’t think it affects SoC% to first order, but my experience with cold packs is limited). In addition, as mentioned just now, with the slider or really any method except charging to 100% you are subject to at a minimum 1% error due to rounding error on the %SoC unless you carefully manually watch for the change in % between two numbers (where presumably it is at about x.5). This error results in much larger variation than 1% when extrapolating from a very low SoC. The number of rated miles remaining contains hidden precision available (one or two extra digits) in the API so I don’t think that contributes significantly to extrapolation error.
But in any case these variations are not of any consequence - significant changes are the 5-10% changes (15-30 miles) people see with a warmed-up battery vs. when their car was new.
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Msjulie
Active Member
It seems that so far, folks get an average degradation of 10% on the model 3 for the 1st year.
I was under the impression that it was supposed to be 5% for the 1st year.
If batteries continue degrading at this rate, it is going to cost a fortune to Tesla.
In any case if we lose close to 30% over 8 years, it is a lot lower than what was expected.
I was under the impression that it was supposed to be 5% for the 1st year.
If batteries continue degrading at this rate, it is going to cost a fortune to Tesla.
In any case if we lose close to 30% over 8 years, it is a lot lower than what was expected.
Msjulie
Active Member
From 300 to 200 sounds pretty painful to me, regardless of expectations. Friends with Model S have not reported that much loss but to be fair I don't have thousands of friends with Model S cars
Yes, i didn't express myself properly. What i meant is close to 30% is way too much degradation.
AlanSubie4Life
Efficiency Obsessed Member
You guys seems to be in the “less fortunate” of the two Gaussian distributions. You can poke around for the picture of the distributions generated from Stats. It’s bimodal for the Dual Motor. Anecdotally, it seems like cars in that general timeframe tend to be at that ~285 rated miles at 100% number.
Anyway I think it is unlikely that you’ll continue to lose available capacity at that rate.
But definitely it seems any Model 3 buyer should expect 10% range loss and account for that when they buy. For whatever reason the range loss appears to be worse on Model 3 than Model S. Not really that surprising of course given a different chemistry and a new cell.
We’ll see what happens! Maybe it is not permanent!
Anyway I think it is unlikely that you’ll continue to lose available capacity at that rate.
But definitely it seems any Model 3 buyer should expect 10% range loss and account for that when they buy. For whatever reason the range loss appears to be worse on Model 3 than Model S. Not really that surprising of course given a different chemistry and a new cell.
We’ll see what happens! Maybe it is not permanent!
Here's the Stats histogram posted in October. If one assumes a one-year old Model 3 typically has 10k to 15k miles driven, then looking at the distribution for AWD, indicates averages of 307 miles for the 10k down to around 300 miles for the 13k to 15k miles. That's 1 to 3% deg.
Similarly, the RWD models show a range of 315 miles to 310 miles between 10k and 15k, also within 3% deg.
AlanSubie4Life
Efficiency Obsessed Member
These are averages. You can see from the distributions above that 286 miles or below or so is quite common - probably about 3-5% of people just eyeballing it.
So there is nothing unusual about that result. Just a bit below average.
On the plus side, there are probably people with similar vintage cars with similar mileage above 305 miles or so! Just luck of the draw.
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