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Charging time 6.6kW charger for 2019 Tesla Model 3 SR+

I was wondering if anyone could give me an estimate of the approx time to charge my 2019 model 3 SR+ from say 5% - 98% on a 6.6kW J1772 home charger?
For my job I usually drive 200-300km 5 days a week. I rent a condo that does not have a charger so I usually end up sitting at a supercharger every day after work for an hour. I have an opportunity to buy a condo with a charger. The seller was nice enough to let me plug in my car for a few minutes. The car told me it would take 6.5h to charge from 25% to 100% but I know from experience that it always takes 1.5-2x longer than what my Tesla says. I need to be able to fully charge overnight for work and I don't want to buy this place if it turns out I still would have to go to the supercharger.

Thanks for any advice. Sorry if this question has been asked before.
 

Sophias_dad

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Jul 29, 2018
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So... the battery in the SR+ is around 54kwh usable. Divide that by 6.6, and you have 8.18 hours for an absolute full (0-100% charge). There's some losses in there, so its probably more like 9 hours 0-100. If we instead fill only 93%(5-98%), you get 7.6 hours, round that up to 8 or just a bit more, but not more than 9. Thinking further on it, since you are nearing the 'full' limit on the battery, charging is likely to slow down considerably for the last few percent. Maybe 10 hours.

BTW, you really shouldn't be making a habit of 5-98% cycling. IMHO you should have gotten an LR if you need that kind of range.
 
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So... the battery in the SR+ is around 54kwh usable. Divide that by 6.6, and you have 8.18 hours for an absolute full (0-100% charge). There's some losses in there, so its probably more like 9 hours 0-100. If we instead fill only 93%(5-98%), you get 7.6 hours, round that up to 8 or just a bit more, but not more than 9. Thinking further on it, since you are nearing the 'full' limit on the battery, charging is likely to slow down considerably for the last few percent. Maybe 10 hours.

BTW, you really shouldn't be making a habit of 5-98% cycling. IMHO you should have gotten an LR if you need that kind of range.

Thanks very much for your help. I've done the math but was hoping someone could provide an estimate based on their real world experience, especially considering how much slower charging can be when the battery is almost full.
I also know the continual cycling is not ideal but I couldn't afford a larger battery, unfortunately
 
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jjrandorin

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Riverside Co. CA
Thanks very much for your help. I've done the math but was hoping someone could provide an estimate based on their real world experience, especially considering how much slower charging can be when the battery is almost full.
I also know the continual cycling is not ideal but I couldn't afford a larger battery, unfortunately

The charging speed does not slow down hardly at all when "slow" charging.... and ALL home charging, at ANY L2 speed is "slow" charging to a tesla (exception... I havent really timed it above 93-94%).

So, the estimate you saw in your car when connected to the L2 charging connection for that condo was correct, to within a few minutes at least, unlike with supercharging where there is a huge taper in speed when you get past 80%. You should be able to fully charge your car from almost empty to pretty much full "overnight" or 8-9 hours on that connection.
 
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The charging speed does not slow down hardly at all when "slow" charging.... and ALL home charging, at ANY L2 speed is "slow" charging to a tesla (exception... I havent really timed it above 93-94%).

So, the estimate you saw in your car when connected to the L2 charging connection for that condo was correct, to within a few minutes at least, unlike with supercharging where there is a huge taper in speed when you get past 80%. You should be able to fully charge your car from almost empty to pretty much full "overnight" or 8-9 hours on that connection.
Okay great! That's what I was wondering... If there was a large taper similar when I'm supercharging. It makes sense that there is not, but I wasn't 100% sure and didn't want to buy only to find out it would take more than 10h to charge my car.
Thanks everyone for your help
 
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I think charging is about 83% efficient?
If so then assume 50 KWH is needed to add to the battery so 54 div by 6.6 = 8.2 hours, but div by .83 to account for efficiency loss = 9.8 hours.

I’m not sure about this as I don’t have actual experience, but it should be close unless of course there are considerations I don’t know about or haven’t taken into account, like cold temps that will use some of that 6.6 KW to heat the battery?
 
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jjrandorin

Moderator, Model 3, Tesla Energy Forums
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Nov 28, 2018
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Riverside Co. CA
Combining all the other comments...

basically the SR is not going to work for you if you need to use 5 - 98% everyday. The winter range will be cut 30% so it doesn't even matter if you can charge at home. You won't make it to work in the winter.

From the OPs post, it sounds like they already have the car, and have already been "making it work" by supercharging because they didnt have home charging. LR would be better, for sure, but they have the car.
 
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ItsNotAboutTheMoney

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Jul 12, 2012
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Combining all the other comments...

basically the SR is not going to work for you if you need to use 5 - 98% everyday. The winter range will be cut 30% so it doesn't even matter if you can charge at home. You won't make it to work in the winter.


The OP lives in Nanaimo, on Vancouver Island, which has a winter climate with average lows around freezing and average highs in the 40sF.
Also, they wrote driving 200km to 300km, not 300km every day, so their driving pattern is obviously variable.
200km is about 125 miles. 300km is about 187 miles.

I would say that assuming their driving is in the Nanaimo or Vancouver climate, while the home charging wouldn't entirely eliminate the Supercharger stops, I think that it would eliminate them for a large number of days in the year, including some winter days with lower distance driving. In addition, if they did need to stop at the Supercharger, it would be a top up, rather than having to do slow charging to near full.

Obviously this would depend on driving speeds, and other factors like how their driving is spread through the day.
 
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Rocky_H

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Feb 19, 2015
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If there was a large taper similar when I'm supercharging. It makes sense that there is not, but I wasn't 100% sure
The taper is there; it always is. But you are not thinking about what the power levels are. When you are thinking about Superchargers "slowing down", that is coming down from 100kW! !!! It's reducing to 60, 40, 20 kW. By the time it's getting down to 30 or 20, you are at the point of getting impatient and rolling your eyes because it's "so slow", and the % full is really high at that point. But think about what that 20 kW is. It's still more than double what this 6.6 kW home charging connection will be. That 6.6 kW won't have to reduce any at all until the car is about 95% or more full.
 
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Sophias_dad

Active Member
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Jul 29, 2018
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Massachusetts
I think charging is about 83% efficient?
If so then assume 50 KWH is needed to add to the battery so 54 div by 6.6 = 8.2 hours, but div by .83 to account for efficiency loss = 9.8 hours.

I’m not sure about this as I don’t have actual experience, but it should be close unless of course there are considerations I don’t know about or haven’t taken into account, like cold temps that will use some of that 6.6 KW to heat the battery?
From other posts around TMC, I find that 32x240 is actually the most efficient, at 95%, while 12x120 is the least(by far) at 85%. It makes sense, since the car has to be kept awake during the entire charging event using some portion of the power delivered to it. It likely also gets worse if the ambient temperature drops, as the battery has to be kept (or gotten) warm. This latter effect MIGHT not be a problem if the car is plugged in immediately after driving, since the act of charging might be enough to keep the battery warm.
 
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