HAHAHAHA! Three days, 60 posts, and the OP doesn't seem to understand ANYTHING!!!!
Time for a moderator to step in, either closing the thread, or eliminating it completely, as all the info contained is available on multiple posts elsewhere.
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Why only 40 miles per hour on Gen 3 Tesla Wall Charger for MYP?
- Thread starter maximusa
- Start date
Time for a moderator to step in, either closing the thread, or eliminating it completely, as all the info contained is available on multiple posts elsewhere.
LOL... I don't think the OP is considering getting the smaller wheels, just telling the car in the service menu that the smaller wheels are there... *just* so that the charging screen can say "+44mph"
LOL... I don't think the OP is considering getting the smaller wheels, just telling the car in the service menu that the smaller wheels are there... *just* so that the charging screen can say "+44mph"
And it may not even work...BUT I will say that it would be interesting to see if the car is using that information to recalculate efficiency for purposes of the charging screen metrics.
No, he would change the efficiency at which he USED the energy that was put into the battery, but he would not change the rate at which ENERGY(kWh) is added.
Another way to look at it is... that a change of miles per hour added, at the same power input, is not a change in speed of adding energy into the car.
Another statement... The kW RATE of charge is not affected by the driving efficiency of the vehicle, but it seems that the "miles per hour" value IS affected by the driving efficiency(or vehicle perceived driving efficiency)...BUT again, miles per hour is not the way to figure out if you have a power issue.
SilverSp33d3r
No Longer Silver
I believe you meant Wh/mile not MPH. The Tesla Wh/mi since last charge, Trip A and Trip B only tracks energy used while driving. Energy used for Sentry mode, Cabin Overheat Protection is tracked tracked under energy use while parked.
Yes but if you could make a change to your car.. say take half the battery out and double your efficiency your effectively charging at twice the useful speed with the same power input..
In the same respect if you increase your efficiency you are increasing your useful driveable range per hour even with the same power input... the miles per hour of charge is not a useless metric because you want to make sure it's fast enough to get you to where you want to go by the time you need to leave..
It's easy to ignore or call a worthless metric since Teslas are so efficient but plug in an f150 lightning to the same plug (11kw) and you will find you're not going to get near as far in a few hours charging as you are in the Tesla since it's so inefficient
SilverSp33d3r
No Longer Silver
False. When charging the additional draw of sentry/cabin overheat will result in less of the charging power from the wall getting into the battery. That will result in the car showing less miles per hour being displayed in the app as the charging rate.
Plug your car in, start charging turn on/off sentry mode, cabin overheat or hvac and you will see a reduction of the “mph” stated for charging.
Not in my experience. I usually charge at a public Level 2 charging station with Sentry mode enabled. My Model Y locks as I walk away. My Model Y remains awake while charging. Whether or not Sentry mode is enabled would not make a difference, i.e. the overhead of ~230W while the Tesla Model Y is awake while charging.
I do observe a lower charging rate if Climate Control is active when I sitting in my Model Y as charging completes. In that case the effective charging rate can be reduced by up to 1/3rd (4kW instead of 6kW) as the Climate Control in summer in an underground parking garage consumes ~2kW. COP with AC enabled could reduce the effective charging rate and show fewer miles per hour being added to the battery.
All right. I'm very late to this party, but there's been a fair amount of not-quite-but-it's-close commentary going on about charge rates and so on. I give the below lecture about once a month, so it seems that it's time, here.
First, definitions:
So, in all of this, What The Heck Is A KiloWatt-Hour? Answer: The amount of energy used if one uses one thousands Watts for One Hour. The relationship between Joules and kW-hr is 1 kW-hr = 3.6 MJ. (That is: 1000W * 3,600 seconds).
For various historical reasons, the energy that one gets billed for by the electric company comes in chunks of kW-hr's. I get charged about $0.18/kW-hr around these parts. (This is the same reasoning that has people talking about costs of money in dollars, rather than pennies: Hey, that widget is $5.37! But nobody runs around saying, "That widget is 537 pennies!". You get the idea.)
By the by: That 100W lightbulb in the overhead? Yep, it's using 100 Joules per second so long as the blame thing is on. Leave it on for an hour and it uses 100W-hr of energy.
So, because the power companies hither and yon like to charge for energy in kW-hr, the people who make largish batteries tend to rate their capacity for energy in kW-hrs as well.
Now, if one is running a Tesla across the landscape, or any BEV for that matter, the efficiency of the car is based on how much energy it takes to go a mile, at least in the U.S.. (Overseas, they play kilometers, but that's them.) The EPA tracks that stuff and one can find all the lurid details at fueleconomy.gov.
So, if one is talking about, "How many miles of charge per hour" one is actually talking about two things:
Now for the first: Say one has a Wall Connector (darn it, these things are not chargers. The actual charger is in the car.) Let's say VAC is 240 V and one is getting 48A. Power input to the car (remember, rate!) is 240 * 48 = 11.52 kW.
You can probably see where this is going. How many miles of charge per hour is this?
MoCpH = (11520W)*(1 mile/(300W-hr)) = 38.4 Miles/hr.
Let's change things around a bit. Suppose the City Power at the OP's place isn't 240 VAC. At mine, as it so it happens, I have 245 VAC. The current is set by the car, so the input power, when charging, would be 245V * 48A = 11.76 kW. Charge rate for the OP's car at my place would then be:
MoCpH = (11,760W) * (1 mile/300W-hr) = 39.2 Miles/hr.
If the air conditioning is off, I'd expect the MoCpH number to go up by a Mile per hour: The AC uses energy. And there's your 40 MoCpH number.
Now, my spouse runs around in a 2021 MY LR. According to the EPA and the Mulroney sticker, this car gets 270 W-hr/mile. At 240 VAC, then, the charge rate in miles per hour would be:
MoCpH = (11,520W) * (1 mile/270W-hr) = 42.6 Miles/hr. At the elevated voltage that we have over here, that would be
MoCpH = 11,760W) * (1 mile/270W-hr) = 43.6 Miles/hr
Finally, my daily driver is a 2018 M3 LR RWD. That car gets 260 W-hr/mile. At the 245 VAC we've got here, I get:
MoCpH = (11,760W)*(1 mile/260W-hr) = 45.3 W-hr/mile.
And that last one is about right: I see that all the time. I sometimes get 46 W-hr/mile on that car when the air conditioning and such is off.
When do these numbers get really weird? When one is somewhere over 90% charged, at which point the car slows down the charge rate to prevent damaging the batteries. The other time things get silly is when its cold outside: the battery gets warmed up to charge, and it does that by heating the car coolant by a couple of different methods depending upon make and year, but all those methods use up some energy that goes into heat, not battery charging.
Summary: Don't know how many Teslas the electrician has put in Wall Connectors for, but he/she is dead on with that 40 MoCpH for a Performance Model Y.
As you guys are finding out, what people want to know is not how many kW-hrs are being stuffed into their cars' batteries, but rather what additional distance the car can go per unit of time being charged. So, Tesla does the same calculations as I did above. It's not rocket science. The only difference, I suppose, is that they have the actual numbers for how much energy the car is or isn't putting into heat when the car's being charged, so one gets a bit more accurate number from their charts, since they know that the A/C is off and so on.
First, definitions:
- Energy. Energy is a quantity, like a bucket of water. The SI unit for energy is the Joule.
- Power: Power is a rate, and is energy per time. The SI unit for power happens to be the Watt. And the relationship between the Watt and the Joule is pretty darn direct: A steady rate of 1W is the usage of One Joule Per Second.
So, in all of this, What The Heck Is A KiloWatt-Hour? Answer: The amount of energy used if one uses one thousands Watts for One Hour. The relationship between Joules and kW-hr is 1 kW-hr = 3.6 MJ. (That is: 1000W * 3,600 seconds).
For various historical reasons, the energy that one gets billed for by the electric company comes in chunks of kW-hr's. I get charged about $0.18/kW-hr around these parts. (This is the same reasoning that has people talking about costs of money in dollars, rather than pennies: Hey, that widget is $5.37! But nobody runs around saying, "That widget is 537 pennies!". You get the idea.)
By the by: That 100W lightbulb in the overhead? Yep, it's using 100 Joules per second so long as the blame thing is on. Leave it on for an hour and it uses 100W-hr of energy.
So, because the power companies hither and yon like to charge for energy in kW-hr, the people who make largish batteries tend to rate their capacity for energy in kW-hrs as well.
Now, if one is running a Tesla across the landscape, or any BEV for that matter, the efficiency of the car is based on how much energy it takes to go a mile, at least in the U.S.. (Overseas, they play kilometers, but that's them.) The EPA tracks that stuff and one can find all the lurid details at fueleconomy.gov.
So, if one is talking about, "How many miles of charge per hour" one is actually talking about two things:
- How much energy one is stuffing into the battery per hour. (That's kW-hr's, again).
- What the efficiency of the car happens to be.
Now for the first: Say one has a Wall Connector (darn it, these things are not chargers. The actual charger is in the car.) Let's say VAC is 240 V and one is getting 48A. Power input to the car (remember, rate!) is 240 * 48 = 11.52 kW.
You can probably see where this is going. How many miles of charge per hour is this?
MoCpH = (11520W)*(1 mile/(300W-hr)) = 38.4 Miles/hr.
Let's change things around a bit. Suppose the City Power at the OP's place isn't 240 VAC. At mine, as it so it happens, I have 245 VAC. The current is set by the car, so the input power, when charging, would be 245V * 48A = 11.76 kW. Charge rate for the OP's car at my place would then be:
MoCpH = (11,760W) * (1 mile/300W-hr) = 39.2 Miles/hr.
If the air conditioning is off, I'd expect the MoCpH number to go up by a Mile per hour: The AC uses energy. And there's your 40 MoCpH number.
Now, my spouse runs around in a 2021 MY LR. According to the EPA and the Mulroney sticker, this car gets 270 W-hr/mile. At 240 VAC, then, the charge rate in miles per hour would be:
MoCpH = (11,520W) * (1 mile/270W-hr) = 42.6 Miles/hr. At the elevated voltage that we have over here, that would be
MoCpH = 11,760W) * (1 mile/270W-hr) = 43.6 Miles/hr
Finally, my daily driver is a 2018 M3 LR RWD. That car gets 260 W-hr/mile. At the 245 VAC we've got here, I get:
MoCpH = (11,760W)*(1 mile/260W-hr) = 45.3 W-hr/mile.
And that last one is about right: I see that all the time. I sometimes get 46 W-hr/mile on that car when the air conditioning and such is off.
When do these numbers get really weird? When one is somewhere over 90% charged, at which point the car slows down the charge rate to prevent damaging the batteries. The other time things get silly is when its cold outside: the battery gets warmed up to charge, and it does that by heating the car coolant by a couple of different methods depending upon make and year, but all those methods use up some energy that goes into heat, not battery charging.
Summary: Don't know how many Teslas the electrician has put in Wall Connectors for, but he/she is dead on with that 40 MoCpH for a Performance Model Y.
As you guys are finding out, what people want to know is not how many kW-hrs are being stuffed into their cars' batteries, but rather what additional distance the car can go per unit of time being charged. So, Tesla does the same calculations as I did above. It's not rocket science. The only difference, I suppose, is that they have the actual numbers for how much energy the car is or isn't putting into heat when the car's being charged, so one gets a bit more accurate number from their charts, since they know that the A/C is off and so on.
No. If you started with a 100kWh battery and charged at lets make this simple, 10kW, it would take 10 hours to charge(with no charge curves)...if you now half that battery size to 50kWh it will charge in 5 hours, half the time, but ONLY because the battery half the capacity. It has NOTHING to do with the EFFICIENCY of the vehicle.
You are mixing up actual charging(energy) speed and you just said it "useful" charging speed. There is a difference and this is where there is confusion with the OP, you, and others.
Yes, but again I understand that the OP, you , and others are fixating on that miles per hour "rate" but we are trying to explain to you why there is a discrepancy there. I understand why Tesla put that number in the chart, but it confuses the issue because lots of things can change that mph rate. On my 2018 LR RWD, there is what a 3-10% efficiency change whether I have the aero covers on or not...that would change the useable charge rate by 1 to 4mph. That isn't in that chart either.
The OP in this thread is insinuating by their comments that they aren't getting the appropriate charging rate but they are using the wrong metric to make the argument. We are trying to explain what the correct metric for that is.
The charger knows power, it doesn't care what it is putting it in and how efficient the system that the item is in is.
...HAHAHA...BUT the OP doesn't seem to yet understand "it's working as designed."
That's the root of the problem right there. Charge is measured in Coulombs, Charge rate is measured in Amps, power is then this rate times voltage (Watts), and accumulated power (energy) is measured in Joules (or equivalently, kWh). None of these have anything to do with distance or speed.
The problem is that most people don't want a science experiment, but just want to know how far their car can drive if they leave it plugged in for some time. Tesla uses MPH as a "charge rate" to try to address this, but of course efficiency now comes into play. One car will go farther than another on the same amount of energy (kWh). It's not perfect, but it does give a general idea.
The same issue is at play in representing the "fuel gauge" in Miles rather than kWh. Your battery holds energy, not distance. There should be an option to display energy remaining in kWh in my opinion.
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No.. You are mixing up charging speed mph (dependant on efficiency) with charging speed energy...
At the end of the day 10kw of power is pretty worthless if it's only getting you 1 mph it has EVERYTHING to do with the efficiency of the vehicle
Why should Britney from Laguna Beach care about a volt, amp, ohm, or mho? She only cares how long is it going to take and how far can I go
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Meh.. I've never seen a gas gauge with gallons of gas left.. percentage or miles has always been how it's displayed
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