Relying on Supercharging for first 3 months: will it damage my battery?

[Slate]

So it looks like the renovations to my garage won't be finished until mid-Spring or thereabouts. No vehicle to the driveway, much less electricity.

I'm scheduled to take delivery of a LR AWD by the end of this year. I live fairly near a Supercharger--in fact, it's closer than the gas station I usually use in my ICE car.

I'm thinking this should be no big deal, that I can park outside of my garage and use the Supercharger for my needs in the interim. I don't drive much, so charging will be more or less like visiting the gas station now. But I'm also hearing all these cautionary tales about how too much supercharging can damage the batteries. Is this something I really need to worry about, and if so are there steps I can take to minimize damage? It'll be no problem for me to supercharge only in small doses, or reduce the charging rate if that's at all possible.

Alternately, I could run an extension cord to the street and trickle charge, which would also likely be adequate considering pandemic driving.

Any advice? Really don't want to hobble the durability of my new Model 3 right out of the gate.

 

[jjrandorin]

There are people who charge just using superchargers so no, you wont damage your car.

Just dont plan on "charging to full" at a super charger, unless you are going on a trip. Your charging range will be from whatever you run it down to, to 90% max. Your not going to fill it up like a gas car, and you should not "run it down to E" like a gas car either. plan on 20% to 90% or so.

One thing many new owners think is, "My commute is only 20 miles, the car has a 300 mile range, I should be able to hit a supercharger every 12-15 days or so, it will be fine"... and it absolutely will not work that way. As long as you understand that, you should be fine.

 

[Noodles]

One thing many new owners think is, "My commute is only 20 miles, the car has a 300 mile range, I should be able to hit a supercharger every 12-15 days or so, it will be fine"... and it absolutely will not work that way. As long as you understand that, you should be fine.

why not? just drive the car as normal, if the owner doesn't want to SC daily then doing a SC session once a week or one week and a few days seems fine to me

 

[jjrandorin]

why not? just drive the car as normal, if the owner doesn't want to SC daily then doing a SC session once a week or one week and a few days seems fine to me

The entire quote is what wont work ( " i only drive 20 miles a day, the car has 300 miles range, I can supercharge every 12-15 days"). It wont work because:

1. even if the car supposedly has 300 miles range, thats EPA range, and doesnt reflect real world driving
2. Because a person will charge from approximately 20% to approximately 90%, thats approximately 217 miles range if the car has 310 (the new cars extended range is due to heat pump, so lets just use 310).
3. Miles will NOT roll off at a 1 mile driven for 1 "tesla mile". On a 20 mile commute, during the winter, I would expect it to take roughly 30 tesla miles for 20 real miles.

So, 30 miles used a day, 217 miles range from 20% to 90% under this scenario, its about 7 days to go from 20% to 90% and thats not counting someone who is parking outside and wants to use sentry mode (which is 1-2 miles an hour).

Realistically, a person who parks outside and wants to use sentry mode, and has a 20 mile commute, should expect to need to fill up at a supercharger every 5 days. New owners look at the 300 miles range and many times think exactly what I said above" I can supercharge every 12-15 days it will be fine". As long as they realize that no, they will be charging every 5 days, not every 12 to 15, then its fine.

Thats the longer answer to your question.

 

[Noodles]

The entire quote is what wont work ( " i only drive 20 miles a day, the car has 300 miles range, I can supercharge every 12-15 days"). It wont work because:

1. even if the car supposedly has 300 miles range, thats EPA range, and doesnt reflect real world driving
2. Because a person will charge from approximately 20% to approximately 90%, thats approximately 217 miles range if the car has 310 (the new cars extended range is due to heat pump, so lets just use 310).
3. Miles will NOT roll off at a 1 mile driven for 1 "tesla mile". On a 20 mile commute, during the winter, I would expect it to take roughly 30 tesla miles for 20 real miles.

So, 30 miles used a day, 217 miles range from 20% to 90% under this scenario, its about 7 days to go from 20% to 90% and thats not counting someone who is parking outside and wants to use sentry mode (which is 1-2 miles an hour).

Realistically, a person who parks outside and wants to use sentry mode, and has a 20 mile commute, should expect to need to fill up at a supercharge every 5 days. New owners look at the 300 miles range and many times think exactly what I said above" I can supercharge every 12-15 days it will be fine". As long as they realize that no, they will be charging every 5 days, not every 12 to 15, then its fine.

Thats the longer answer to your question.

ahhh you're referring about EPA versus actual range due to usage.
Thank you for the clarification.

 

[bbell]

Alternately, I could run an extension cord to the street and trickle charge, which would also likely be adequate considering pandemic driving.

This.

I don't know what your electrical rates are but home charging is almost always a lower cost and more convenient. If you charge on 120V for 8-10 hours a night you can get 30-40 miles, and more for a longer charge.

 

[Uncle Paul]

Agree that a good plan B would be to run a long 120V extension cord down to the street and get a slow charge all night. Might save you some trips to the Supercharger.

 

[Matsayz]

This.

I don't know what your electrical rates are but home charging is almost always a lower cost and more convenient. If you charge on 120V for 8-10 hours a night you can get 30-40 miles, and more for a longer charge.

Yeah, extension cord but make sure it's a legit cable... don't cheap out. Also, how long is this supposed run from the house to the car going to be? I still wouldn't mind the supercharger option, I did that for a month when we sold our house super fast and had to airbnb for 30days. It worked just fine even in the winter of Colorado... it was just slow because the battery was so cold.

 

[OCR1]

I use up more range by just having the car sit around my garage than I do driving my car. And I don't even use sentry mode in the garage. Cold weather, opening and closing the door, accessing the car via the app, logging data through TeslaFi...all takes up energy. And when I do my normal 2 mile commute I use up at least 6 miles because of the inefficiencies of short trips.

 

[Slate]

Thanks for the feedback. I do have a proper extension cord picked out, and I even installed a 120 (not 110) external outlet so I could charge a little faster, but the overall arrangement may just be too unwieldy and ultimately impractical for the steep hillside of my house.

Just want to make sure that if I do have to rely on the nearby SC, it wouldn't be detrimental so long as I don't try to keep it "topped off" with 100% charges, etc.

 

[SageBrush]

are there steps I can take to minimize damage.

Yes

Avoid charging to a higher SoC if possible. Less than 90% for sure, 80% if you can
Consider using an urban supercharger limited to 75 kW

---
How detrimental is Supercharger use ? The qualitative answer is very little each session, but it is cumulative. Going by anecdotes of truly heavy Supercharger use (daily or close to it, over years) and battery degradation I'd say you are fine until the Spring if you follow the above mitigations.

 

[Mr X]

Nope don't worry about it


I have free supercharging and supercharge almost exclusively. Every 3 days or so. Since Sep 2019, my car has been getting the same consistent range.


And I always charge to 90%

 

[CertLive]

You will be just fine supercharging. The BMS is mature and takes care of the batteries whatever way you charge them.

 

[iamnid]

I wouldn't worry too much about it. I follow Outofspecmotoring on youtube and he seems to supercharge ALL the time for thousands and thousands of miles worth of travel. He did a recent video regarding degradation and it didn't seem like he had much.

 

[SageBrush]

I wouldn't worry too much about it. I follow Outofspecmotoring on youtube and he seems to supercharge ALL the time for thousands and thousands of miles worth of travel. He did a recent video regarding degradation and it didn't seem like he had much.

Anecdotes aside (although they are useful), Tesla gives us a yardstick to go by since a car's maximum charging power is nerfed after it reaches a threshold number of supercharger events in order to protect the battery from excessive degradation. Bjorn Nyland's Model 3 has reached that threshold. I don't recall specifics although it is A LOT. And the nerf is only down to ~ 90 kW.

 

[JCtx]

and that's not counting someone who is parking outside and wants to use sentry mode (which is 1-2 miles an hour).

Hey guys, semi-ignorant EV potential owner here, so bare with me . What exactly does 'sentry mode' do? And when are you supposed to use it? Just curious. And is it only available on 2021 cars with the new heat pump? Thx.

 

[jjrandorin]

Hey guys, semi-ignorant EV potential owner here, so bare with me . What exactly does 'sentry mode' do? And when are you supposed to use it? Just curious. And is it only available on 2021 cars with the new heat pump? Thx.

Sentry mode is a setting that records from the cars cameras as a sort of security camera. Its available on every tesla model 3, and has nothing to do with the heat pump whatsoever.

Because it keeps the car awake, using the sentry mode uses about 1-2 miles per hour of range, so if parked from 7pm to 7am, the car will lose 12 miles to 24 miles of range if this feature is on.

TL ; DR, its a built in extra feature that uses the car's cameras to record its surroundings, and uses a fair amount of power.

 

[sduck]

Thanks for this discussion, it's kind of reassuring. I'm in the process of moving from a house with a garage and a wall charger to an apartment with no available charging, although there's a supercharger less than a mile away. I may be able to run a cord from the apartment to the car for charging, on occasion, depending on parking, but I think I'll be relying on the supercharger a lot.