Level 1 charging speed

[AtlTesly]

I’m charging using a mobile connector plugged into a standard 120 volt home outlet getting 12 amps. Tesla’s documentation states: “A 120 volt outlet will supply 2 to 3 miles of range per hour charged.”

I have a need to charge to 100% with an expected departure at 8am Friday. I upped the charge limit to 100 and plugged in to get an estimated time to fully charge. The math I’m seeing doesn’t make sense. What am I missing?

Current SOC is 81% (267 mi.). MYLR fully charged is 330 mi. So I have 67 miles of charge to go. With 2-3 miles added per hour it should take 21-30 hours to reach 100%.

Why is the car telling me I will be at 100% in 12.5 hours. That’s over 5 miles of ranger per hour being charged.

If it truly will charge this quickly I will plug in the night before and use scheduled departure.

I’m not complaining that I’m getting a faster charge than expected from an L1 charger on a 120 outlet. I would like to know if others have the same experience. Is this normal. Or do I have some fancy voodoo magic outlet/connector?

 

[jjrandorin]

Directly from Teslas website on the mobile connector charge rate (found at the link below)

Mobile Connector | Tesla Support

Mobile Connector is useful when you’re away from home and on extended trips. View the charging speed based on your model and adapter.

www.tesla.com

Model Y = 5MPH charge rate.

TL ; DR - You dont have any special sauce / voodoo outlet. You likely read some old information somewhere on charge rate.

 

[exxxviii]

It’s more like 5 miles per hour. Here’s another way to do your math…

Battery is 81 kWh, and you need to replace 19%, so that is 15.4 kWh. L1 recharges at 1.44 kW. So, it will take 10.7 hours to recharge - 15.4 kWh / 1.44 kW.

 

[Cosmacelf]

I’m charging using a mobile connector plugged into a standard 120 volt home outlet getting 12 amps. Tesla’s documentation states: “A 120 volt outlet will supply 2 to 3 miles of range per hour charged.”

Which documentation? The owners manual, the website? Older Model S/X vehicles would charge at 2-3 miles per hour, but newer Model 3/Y are more efficient.

 

[AtlTesly]

Directly from Teslas website on the mobile connector charge rate (found at the link below)

Mobile Connector | Tesla Support

Mobile Connector is useful when you’re away from home and on extended trips. View the charging speed based on your model and adapter.

www.tesla.com

View attachment 949659


Model Y = 5MPH charge rate.

TL ; DR - You dont have any special sauce / voodoo outlet. You likely read some old information somewhere on charge rate.

Got it straight from the horse’s mouth - Charging Your Tesla. But clearly you are correct.

I recall reading the battery charges slower below 10% and after 90%. Is the estimated time pretty accurate or should I expect it to take longer than estimated?

 

[E90alex]

It’s more like 5 miles per hour. Here’s another way to do your math…

Battery is 81 kWh, and you need to replace 19%, so that is 15.4 kWh. L1 recharges at 1.44 kW. So, it will take 10.7 hours to recharge - 15.4 kWh / 1.44 kW.

About 79 kWh usable so 19% of that is ~15 kWh. Accounting for approx 250W draw from the car being awake you get about 1.19kW into the battery. So about 12.6 hours.

But usually the last 1-2% if charging to 100 can take a lot longer than estimated.

 

[Cosmacelf]

Got it straight from the horse’s mouth - Charging Your Tesla. But clearly you are correct.

I recall reading the battery charges slower below 10% and after 90%. Is the estimated time pretty accurate or should I expect it to take longer than estimated?

At 12A, charge time won't change much at all. I think once it gets to like 98% or 99%, it'll drop below 12A and tail off.

 

[jjrandorin]

Got it straight from the horse’s mouth - Charging Your Tesla. But clearly you are correct.

I recall reading the battery charges slower below 10% and after 90%. Is the estimated time pretty accurate or should I expect it to take longer than estimated?

Tesla used to fudge the number on 120v charging a little lower than it was on model 3/Ys. I always assumed (that word, I know) that it was because The S/X vehicles with the biggest batteries charged at that rate, so it would be "that rate, or faster".

The last 1-2% may take longer due to cell balancing, but there isnt any way to budget for that because its not a known amount of time, it depends on what the cars computers tell it.

 

[jcanoe]

When estimating charging time, i.e. miles per hour added to reach 100% state of charge using Level 1 charging assume 80% charging efficiency.

For my previous vehicle, Gen2 Volt, Level 1 charging at 120V/8A would net just 2.7 miles of range added per hour. Level 1 charging at 120V/12A (the Volt's maximum amperage when charging at Level 1) would net 4 miles of range added per hour while charging. The Gen2 Volt never achieved 5 miles of range per hour added while using Level 1 charging.

 

[Rocky_H]

Tesla’s documentation states: “A 120 volt outlet will supply 2 to 3 miles of range per hour charged.”

That’s over 5 miles of ranger per hour being charged.

Yeah, it's not weird math. It's just that Tesla's documentation on that has been laughably, pathetically wrong for YEARS! I have an old inefficient pig of a 2014 Model S. The old documentation said 3 mi / hour charging rate, and do you know what it gets? Pretty much 3 mi / hour. It's accurate. But several years later, they did the "Raven" efficiency improvements, and it still said 3. Later, they came out with the vastly more efficient Model 3 and Model Y, and they still copied and pasted it and kept that 3 number in their documentation, which was just blatantly wrong by that point.

They updated the numbers on all of the other circuit levels, but for 120V 15A circuits, they for some reason never corrected that 3 number.

Directly from Teslas website on the mobile connector charge rate (found at the link below)

Model Y = 5MPH charge rate.

Huh. Thanks for finding that. Today is the first time I have EVER seen that Tesla finally corrected this anywhere after several years of it being wrong.

 

[zroger73]

I normally charge at home using a Wall Connector. Yesterday, I experimented with level 1 charging just for fun.

I started the day with an 80% charge. I drove 30 miles to work and back and ended the day with a 70% charge. Most of my commute is 60 MPH highway with the rest being 45-55 MPH and about 6 stops.

I began charging from a standard 120-volt, 15-amp outlet at 8:19pm using a Mobile Connector. Charging completed at 80% at 2:41am.

The vehicle showed I used 8 kWh. My Kill-A-Watt power meter showed I used 9.33 kWh representing a charging loss of 14%, which was less than I expected.

30 miles / 6.4 hours = 4.7 miles of real-world range per hour

I'll continue charging using a Wall Connector even though it is unnecessarily fast for my use if for no other reason than being more efficient due to the vehicle not having to stay awake as long to charge (45 minutes vs. 6-1/2 hours.).

As a side note, I had my first Supercharging experience over the weekend after 2 months of ownership. It was not necessary - I had plenty of charge to make it back home, but I wanted the experience. It took 22 minutes to go from 50% to 80%. The charging rate was 74 kWh, which was much lower than I expected - I later learned that older Superchargers like the one I used share power between two vehicles and there was someone charging at stall 2A (I was using 2B). I hindsight, I now know why I got a less-than-friendly glance from the owner at 2A.

 

[JKennedy442]

When estimating charging time, i.e. miles per hour added to reach 100% state of charge using Level 1 charging assume 80% charging efficiency.

For my previous vehicle, Gen2 Volt, Level 1 charging at 120V/8A would net just 2.7 miles of range added per hour. Level 1 charging at 120V/12A (the Volt's maximum amperage when charging at Level 1) would net 4 miles of range added per hour while charging. The Gen2 Volt never achieved 5 miles of range per hour added while using Level 1 charging.

Nice that was my last car too, a 2018 Volt. The reason why the Volt only got 4 miles per hour range is because you could actually achieve or exceed the rated range on that car. Has anyone ever done that in a Tesla?

 

[jjrandorin]

Yeah, it's not weird math. It's just that Tesla's documentation on that has been laughably, pathetically wrong for YEARS! I have an old inefficient pig of a 2014 Model S. The old documentation said 3 mi / hour charging rate, and do you know what it gets? Pretty much 3 mi / hour. It's accurate. But several years later, they did the "Raven" efficiency improvements, and it still said 3. Later, they came out with the vastly more efficient Model 3 and Model Y, and they still copied and pasted it and kept that 3 number in their documentation, which was just blatantly wrong by that point.

They updated the numbers on all of the other circuit levels, but for 120V 15A circuits, they for some reason never corrected that 3 number.


Huh. Thanks for finding that. Today is the first time I have EVER seen that Tesla finally corrected this anywhere after several years of it being wrong.

Yeah, I found that a couple of months ago when I was replying to another thread on this topic. I was looking to copy the charging grid, and make a post about how Tesla has always rated Level 1 charging for model 3 / Y too low, then I saw that they had listed it with a more realistic number. I had the same reaction you did ("huh, thats been wrong since I got my car in 2018, wonder when they finally corrected the chart?").

 

[jcanoe]

Nice that was my last car too, a 2018 Volt. The reason why the Volt only got 4 miles per hour range is because you could actually achieve or exceed the rated range on that car. Has anyone ever done that in a Tesla?

Yes; I believe that there are a few Tesla Model Y logging data on Teslfi that have been able to achieve ~350 mile range. You can achieve 200 Wh/mi or lower consumption in the Tesla Model Y if you drive no faster than 45 MPH on flat terrain, assuming dry roads with no head or cross wind, no AC or heat when using the Climate Control.

 

[E90alex]

Yes; I believe that there are a few Tesla Model Y logging data on Teslfi that have been able to achieve ~350 mile range. You can achieve 200 Wh/mi or lower consumption in the Tesla Model Y if you drive no faster than 45 MPH on flat terrain, assuming dry roads with no head or cross wind, no AC or heat when using the Climate Control.

Sure, but that’s not realistic real world usage.

 

[jcanoe]

Sure, but that’s not realistic real world usage.

True for most Tesla Model Y owners. Some live for the challenge of extracting the maximum range, efficiency from their Tesla vehicle (that's not me).

 

[Rocky_H]

Sure, but that’s not realistic real world usage.

Well, when someone uses the absolute words "anyone" and "ever" then it opens it up to every kind of wild and unrealistic scenario there is.

Has anyone ever done that in a Tesla?

 

[jcanoe]

To achieve 350 miles of range your consumption would need to be no more than ~225 Wh/mi; achievable if you drive 45 MPH average speed without the use of climate control. My lifetime energy consumption is 18% higher than 225Wh/mi and I make no special adjustments to my driving speed or style (mostly driving local roads no faster than 45 MPH using climate control.)

 

[JKennedy442]

Well, when someone uses the absolute words "anyone" and "ever" then it opens it up to every kind of wild and unrealistic scenario there is.

Yeah I guess I should have clarified "with regular use". In the Volt I never tried to get above the rated 53 but I would often was the point.