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No home charging option for first year of Model Y

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Hi All, I have booked my Model Y and estimated delivery is in May 2022. I don’t have home charging available in my condo. So for initial period could be 10-12 months I might be using super chargers mostly. I average 12000 miles during that time so approximately 50 times of supercharging in an year. Do you think it will degrade the battery performance in long run. Service advisor says it’s totally fine but wanted to seek advice from experienced people.

Thanks
 
I think EV manufacturers should provide battery charging guidance for different use cases. Daily driving and charging would be most applicable. Next would be leaving the vehicle parked for several weeks, perhaps as long as 30 days. Finally, long term battery maintenance.

GM offered some guidance with the Chevrolet Volt vehicle. The Volt Owners Manual stated that if the Volt was not going to be driven for up to 4 weeks that you should leave the Volt plugged in. If longer than 4 weeks then you should leave the high voltage battery at 30% state of charge and not plug in the Volt. The 12V AGM battery required either a trickle charger or disconnecting the negative cable from the 12V battery while the Volt was being stored.
 
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The statement above is not quite right.

Best to operate the battery between 20% and 80%.

Slightly not as good is to operate between 10% and 90%.

Finally, minimize charging to 100%, and never, ever, let your battery get to zero%...

Regarding zero% state: if you arrive at your destination with 10% or less, you need to start charging right away, while the battery is still warm. If you let it cool down (say overnight), it could end up at zero on its own.

If you are storing your car (say 1 month+), then plug car in, set charge setpoint at 50%... car will cycle between 48% and 51% on its own...
Below is a link to a reference article that gives pretty good details:

A key point is to center charge / discharge around 50% - that seems to be best. So 80% to 20% gets you a minimal amount of deterioration, while giving you a good range for daily usage. 70% to 30% is even better, but it has diminishing improvement in longevity of battery.

So, in my personal case, my daily driving habits in the Los Angeles basin make it such that charging to 80% every day, allows me to pull in at night with 20% to 40% remaining... making things very comfortable.

Please note, you should charge every day... Don't charge to 80% and then keep driving multiple days, till you get down to 20%...
 
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That's definitely false. I don't know why so many people misunderstand that and think that the voltage is this magical thing, which is all that matters. It's not. It doesn't matter any more than current. This efficiency factor is because of POWER, which is the rate of energy per time. And that depends equally on the voltage and amperage.

Let's say you have 120V on a 30A circuit, so feeding 24A. A TT-30 outlet at a campground is an example of that. That is 2,880 Watts.

So what about a 6-15 outlet, which is 240V feeding 12A? That is also 2,880 Watts. The car is going to convert that 2,880 W to put into the battery pack anyway, and the efficiency will be about identical.

And when you say regardless of amperage, that's not true. There are 5-50 outlets, which are 120V 50A. If you got 120V and 40A feed from that, you would be getting 4.8 kW from it, definitely faster and more efficient than the 240V 12A.
Rocky H:

The energy losses through the wire are only dependent on the Amperage and not the Voltage. These losses are typically 1-2% of the power delivered, with the losses going into heating the wire itself. You will observe these losses in 2 ways:
  • The wire will get warmer as you increase amperage - In the case of 12 gauge wire, code tells you that you will lose 2% of voltage at 20 Amps.
  • The voltage will drop: At the circuit breaker you will measure voltage at 240V, but at the car plug you might only measure 235V.
In the above example the energy losses are the 5V drop X 20 Amps = 100Watts of losses.
You delivered 235V X 20Amps = 4,700Watts to your vehicle or piece of equipment you are trying to power. Of the 4,800Watts that you paid for at the meter, 2.1% were lost due to heating up the wire.
 
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Thank you all for your amazing responses and sharing great knowledge. This was the response I received from my service advisor:
In regard to your concerns about charging, you can rely on supercharging but it is not ideal. The main reason for that is convenience and it will accelerate the degradation of your battery pack faster than if you were to use a home charging solution.

It is not recommended to use supercharging as your primary means to charge as over time, your battery back will lose capacity faster than in comparison to using a Tesla wall connector or outlet. However, the frequency of how often you supercharge is a factor as well. If you are supercharging 1-2 times a week versus 4-5 times a week will affect your car differently.

Now it does sound like this will only be temporary but I would recommend getting home charging at your earliest convenience in order to preserve the long term battery back health as much as possible. I hope this was helpful.


But based on your response I think it’s ok to operate on supercharger being mindful of not avoiding high voltage SC and don’t wait for battery to completely drain. So I would operate between 20-80% and charge my batteries from 50-80%. So if I charger 30% every week on SC I can add roughly around 80 miles. For rest I have to search for level 2 chargers. Can anybody verify this approach. Thanks
As with many charging-related threads, so many people go off on tangents like volts and amps without answering what the OP is asking.

You’ll regret this approach IMO. Spending so much time looking for as well as actually charging will become a quality of life issue. Your significant other will hate you and your choice of car. Unless you don’t have one and the value of your free time is zero, you’ll regret this approach.
 
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Rocky H:

The energy losses through the wire are only dependent on the Amperage and not the Voltage.
Yes, and I did cover that two comments later in #35. You were replying to #33 where I hadn't mentioned it yet.

I'm talking about the pretty general principle where the car has some consistent overhead power consumption during the charging process of 300-400 W. If you only have 1,000 W to work with, that is going to be horribly inefficient versus 6,000+ W. Even if the 1,000 W source is higher voltage, the consumption losses over a much longer charging time are going to be bad and create terrible efficiency just because of the total power being so low. Some loss in the wire is a much smaller effect.

Yes, I know there aren't many practical situations where this is applicable, but it's more about how the statement "Higher voltage is always more efficient" is too absolute to be fully true all the time.
 
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Yes, and I did cover that two comments later in #35. You were replying to #33 where I hadn't mentioned it yet.

I'm talking about the pretty general principle where the car has some consistent overhead power consumption during the charging process of 300-400 W. If you only have 1,000 W to work with, that is going to be horribly inefficient versus 6,000+ W. Even if the 1,000 W source is higher voltage, the consumption losses over a much longer charging time are going to be bad and create terrible efficiency just because of the total power being so low. Some loss in the wire is a much smaller effect.

Yes, I know there aren't many practical situations where this is applicable, but it's more about how the statement "Higher voltage is always more efficient" is too absolute to be fully true all the time.
I have not observed a fixed overhead energy cost of 300-400W associated with charging. The car itself does have an overhead energy usage - but it is a usage / hour (24/7)... unrelated to charging.

I do think the charging processes within the car have some inefficiencies... but I perceive them as a percentage loss, proportional to charging rate... Is it a linear loss? I am not sure, as I only have anecdotal evidence of this behavior. As examples:
  • At peak supercharging, cooling systems are operating at peak rates, using quite a bit of power.
  • At my home, in the 11 to 17 Kw charge rate range, cooling systems are operating but at much slower rates.
  • At low charge rates, such as using a 110V circuit, I have not perceived any cooling activity. Last week, such a situation arose for me at an oddball hotel - I was inputting 1200W into the car and netted overnight 4.2 miles per hour (worth approximately 1100W of power)... about what I would expect in the model Y. If there was a 300-400W burden, I would have ended up at a lower energy gain.
 
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I have not observed a fixed overhead energy cost of 300-400W associated with charging. The car itself does have an overhead energy usage - but it is a usage / hour (24/7)... unrelated to charging.
It's not unrelated to charging. It is an overhead power consumption of the car with running several systems if and only if it is not allowed to turn off and go to sleep. There are only about two or three things that cause this to happen: charging and running sentry mode all the time or just keeping HVAC on. So yes, how long you extend that charging time does directly lead to how long the car needs to stay awake, consuming all of that overhead of energy before it can go back to sleep and cut that power usage. So any kind of very low power source just takes a very long time and wastes more and more of that overhead before it can turn off. That's a known part of charging efficiency issues, so any kind of higher power source can get it over with sooner with less waste.
 
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It's not unrelated to charging. It is an overhead power consumption of the car with running several systems if and only if it is not allowed to turn off and go to sleep. There are only about two or three things that cause this to happen: charging and running sentry mode all the time or just keeping HVAC on. So yes, how long you extend that charging time does directly lead to how long the car needs to stay awake, consuming all of that overhead of energy before it can go back to sleep and cut that power usage. So any kind of very low power source just takes a very long time and wastes more and more of that overhead before it can turn off. That's a known part of charging efficiency issues, so any kind of higher power source can get it over with sooner with less waste.
👍
 
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Please note, you should charge every day... Don't charge to 80% and then keep driving multiple days, till you get down to 20%...
Why is that? There are thousands of EV owners (whether they charge at home or not) that only charge when they need to. I personally only charge at work and charge once every few days. Haven’t noticed any degradation beyond what everyone gets. Wondering if there is scientific proof that the battery is better off being plugged in every day…
 
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This is the only data I have found. Note this is not a “Tesla” battery test, this is a lab test. Draw from this what you will.

8BC25ABF-6AB4-4399-845D-7DA7A32BBC16.png
 
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Why is that? There are thousands of EV owners (whether they charge at home or not) that only charge when they need to. I personally only charge at work and charge once every few days. Haven’t noticed any degradation beyond what everyone gets. Wondering if there is scientific proof that the battery is better off being plugged in every day…
Because that is the recommendation from Tesla. You can do whatever you like, but Tesla probably knows a bit more about the management of their batteries than you do.
 
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Because that is the recommendation from Tesla. You can do whatever you like, but Tesla probably knows a bit more about the management of their batteries than you do.
Just saying “because Tesla said so” doesn’t answer my question though. There must be some kind of scientific reason, or at least empiric proof of that, right?
Unless we’re just supposed to take Tesla’s word as gospel, in which case I must be missing all the Cybertrucks delivered in 2021 in the streets, as well as all the 4680 batteries.
 
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This is the only data I have found. Note this is not a “Tesla” battery test, this is a lab test. Draw from this what you will.

View attachment 791504
Thanks for sending this! I missed it before seeing the following post. I guess my question is: if you use 15% a day, but you charge every day back to 80%, doesn’t that increase the number of cycles, essentially balancing out the other aspect? Meaning if you charge back from 65 to 80 every day, you’ll reach the 1000 cycles 4 times faster than if you charge every 4 days from 20% to 80%, right? Or I might get this all wrong (I’m not trying to be a smartass, genuinely trying to understand more, and also trying to understand how we can hope to have EVs universally used if we’re asking people to have a garage to plug their cars in every day).
 
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Tesla's statement about always leaving the Tesla vehicle plugged in was written over a decade ago. At the time EVs were new to the vast majority of Tesla's customers and consumers in general. It was probably well intended as the Tesla vehicle can become inoperable if you allow the battery pack to become fully discharged.

There are use cases such as when parking in an airport parking lot where the Tesla vehicle can be left unplugged for days, even weeks with no ill effect. Eventually Tesla owners learn they can relax this rule about always plugging in the Tesla vehicle each day in a way that meets their needs. Some have no way to charge at home. These Tesla owners may only charge at work or use public charging infrastructure several times week.
 
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