Home charging at 5 mi/hr (120 v)

[nikolas3]

Picked up my SR+ last week, and the DS told me that charging at a regular 120v outlet is super slow, at about 2-3 mi/hr. Today I wanted to give it a try. I just plugged into the 120v in our garage using Tesla's mobile connector. It reached 5 mi/hr, and has been quite steady so far (at a temp of ~50F)! With less than 20 miles commute per day, this will be enough for me.

One thing about the circuit breaker. I didn't find much safety instruction regarding level 1 charging. Would it still be necessary to have a electrician do a safety examination? I am only living in this place for several months so I don't see much reason to upgrade it to level 2.

 

[Kuhz]

If it’s fast enough for you there is no need to upgrade. Plenty of people do it.

 

[Silicon Desert]

I wouldn't bother about any "safety Inspection" if you are just plugging into a regular 120V outlet. Also 5 mph is about the peak you are ever going to see on a standard outlet, and that is regardless of the temperature. And keep in mind that you will be losing some energy due to "idle losses" (some people call it vampire drain, but's not like some vampire sneaking in during the night to suck electrons from the car Of course you know it is the power the MCU and related items.

 

[Kuhz]

I wouldn't bother about any "safety Inspection" if you are just plugging into a regular 120V outlet. Also 5 mph is about the peak you are ever going to see on a standard outlet, and that is regardless of the temperature. And keep in mind that you will be losing some energy due to "idle losses" (some people call it vampire drain, but's not like some vampire sneaking in during the night to suck electrons from the car Of course you know it is the power the MCU and related items.

Oh it’s actual vampires alright!

 

[nikolas3]

If it’s fast enough for you there is no need to upgrade. Plenty of people do it.

Yes, I am quite happy with the speed of 5mi/hr. I can drive to the nearest supercharger for about 15 minutes if I need more.

 

[nikolas3]

I wouldn't bother about any "safety Inspection" if you are just plugging into a regular 120V outlet. Also 5 mph is about the peak you are ever going to see on a standard outlet, and that is regardless of the temperature. And keep in mind that you will be losing some energy due to "idle losses" (some people call it vampire drain, but's not like some vampire sneaking in during the night to suck electrons from the car Of course you know it is the power the MCU and related items.

Gonna watch closely my utility bill next month.

 

[srs5694]

I charged my Chevy Volt with a Level 1 EVSE for two or three months before getting a Level 2 EVSE, which I'll now be using with my Model 3 once it arrives. The Volt has an official EPA-rated EV range of 53 miles, and with the Level 1 EVSE, it took 12-13 hours to charge, so that's about 4.25 miles per hour. Given that the Volt is less energy-efficient in its EV mode than the Model 3, your 5 miles per hour seems about right.

As to safety, you might want to check to see if the cables and outlet are warm. If they heat up (especially to an uncomfortable degree), then that may be a sign that they're drawing too much power for the wires. Also, try to ensure that nothing else is using the same circuit -- and note that the circuit is likely to include more than one outlet. Your circuit breaker should trip to prevent a safety problem, but that would be an annoyance at best. If you're concerned, you might be able to drop the draw down below 12 amps, but that'll slow charging further. (I don't know how low the Model 3 can set its amperage from a 120v outlet, though.)

 

[nikolas3]

I charged my Chevy Volt with a Level 1 EVSE for two or three months before getting a Level 2 EVSE, which I'll now be using with my Model 3 once it arrives. The Volt has an official EPA-rated EV range of 53 miles, and with the Level 1 EVSE, it took 12-13 hours to charge, so that's about 4.25 miles per hour. Given that the Volt is less energy-efficient in its EV mode than the Model 3, your 5 miles per hour seems about right.

As to safety, you might want to check to see if the cables and outlet are warm. If they heat up (especially to an uncomfortable degree), then that may be a sign that they're drawing too much power for the wires. Also, try to ensure that nothing else is using the same circuit -- and note that the circuit is likely to include more than one outlet. Your circuit breaker should trip to prevent a safety problem, but that would be an annoyance at best. If you're concerned, you might be able to drop the draw down below 12 amps, but that'll slow charging further. (I don't know how low the Model 3 can set its amperage from a 120v outlet, though.)

Very helpful information. Appreciate it. I'm going to check to see if the cables and outlet are warm.

 

[jkoya]

I used the charge cable from my 2016 Volt with the J1772 adapter and I got 5 miles/hr as well.

 

[ewoodrick]

Gonna watch closely my utility bill next month.

This is an easy one, at 20 miles per day, you aren't going to see the charging. Electricity usage varies so much anyway, it is hard to detect the charging.
Basically you are going to get better than 3 miles/kWh 30 miles will be less than 10 kWh and at possible 15 cents per kwH, that's $1.50 a day $45 per month and that's high. In the summer, it can drop to about $15

 

[steve in socal]

I also only commute approx 20-40 miles per day and i can easily replenish overnight on my 120v at 4-5 mph.

 

[Misterbee]

I do the same thing, as I havent really needed to charge any faster yet. I will probably get a faster charger at some point, as I have been told that charging at 120v is less efficient than 240v.

 

[animorph]

Model 3's get about 5 MPH, S & X get 3-4 MPH. I do 120V 15A (12A continuous) while at my son's house with the X. It's enough to cover our local trips for a week and still build us back up to 90% before we leave.

 

[ivan801]

Check and see if your outlet is 20 A (vs 15 A). 20 A looks like it has a T on one side. If it is a 20 A outlet, you can order different plug for your charger from Tesla for $35. It will take you from 12 A continuous charge rate to 16 A.

 

[Snow Drift]

I get 5 mph also. For my wife’s short commute it’s perfect. If we go on a long day trip on Saturday I’ll just charge it most of Sunday. I haven’t used a Supercharger in months.

 

[mswlogo]

This is an easy one, at 20 miles per day, you aren't going to see the charging. Electricity usage varies so much anyway, it is hard to detect the charging.
Basically you are going to get better than 3 miles/kWh 30 miles will be less than 10 kWh and at possible 15 cents per kwH, that's $1.50 a day $45 per month and that's high. In the summer, it can drop to about $15

Hard to notice a $45/mo increase? That would be a 50% increase in my electric bill.

I have a 5 mile one way commute. I’ve been losing about 10 miles a day due to stupid software bugs that don’t let the car go to sleep. My car has 272 wh/m lifetime (mostly winter).

Don’t forget Charging losses. And charging with Level 1 is a little less efficient.

I’m averaging 200 kWh ($50) more a month with a 5 mile (one way commute). I expect it to be about 2/3 of that come summer, not 1/3. I do drive more than my commute of course. I’m averaging about 1000 miles a month so far. Based on 272 wh/m lifetime I’m getting about 32 mpg equivalent based on my $0.25 kWh rate and gasoline being $2.19 a gallon.

I’ve taken my car off WIFI in an experiment to get the car to sleep better. So far it looks promising.

 

[dhrivnak]

Gonna watch closely my utility bill next month.

If you have not done so swap to LED bulbs as that can offset an EV charging load. 120v is fine but slow. I think the 2-3 mph is from X and S which use a lot more power.

 

[srs5694]

This is an easy one, at 20 miles per day, you aren't going to see the charging. Electricity usage varies so much anyway, it is hard to detect the charging.

That's likely to be true for a single month, because of month-to-month variability; however, if you take averages of several months (ideally in year-long increments, to account for seasonal variation), you'll probably see the difference. My bill went up by about $30/month after I got my Chevy Volt. I expect it to go up a tiny bit more (but not much) when I replace the Volt with my Tesla.

There is the caveat, of course, that how much your bill goes up depends on how much you charge at home. If you don't drive much, then the bill won't go up much; and if you do most of your charging elsewhere, your bill won't go up much (but you may pay in some other way).

 

[nikolas3]

So, this morning I checked some of the charging summary: with about 9 hours charge, battery increased from 68% to 86%. The car got 9.5 kwh added, and in total 12.8 kwh was consumed, which brings the charge efficiency to 74.1%.

On the cost side, my current rate is $0.12/kwh, so the total expense is $0.12*12.8=$1.54. The rated miles added is 43.3. That brings to a 28.1 mile per dollar! How nice!

 

[jerry33]

Picked up my SR+ last week, and the DS told me that charging at a regular 120v outlet is super slow, at about 2-3 mi/hr. Today I wanted to give it a try. I just plugged into the 120v in our garage using Tesla's mobile connector. It reached 5 mi/hr, and has been quite steady so far (at a temp of ~50F)! With less than 20 miles commute per day, this will be enough for me.

One thing about the circuit breaker. I didn't find much safety instruction regarding level 1 charging. Would it still be necessary to have a electrician do a safety examination? I am only living in this place for several months so I don't see much reason to upgrade it to level 2.

There's no real reason for a safety examination for L1. You would likely find that a NEMA 14-50 would be more efficient, so your $1.54 might be as low as $1 to $1.30. Just something to consider. Charging at less than 32 amps is inefficient.