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Provided Mobile Connector Power Use Questions - Standard Outlet

Wolfpacker83

Member
May 5, 2021
149
99
NC
I took delivery on June 17 and have only used the provided charger and adapter to charge my Y.
I plug into a standard wall outlet and get about 108/109V and 8A. (I can't get more than 8 because of a freezer also on the same circuit in the garage).

Questions:

1. When my charging is complete, the screen may read +7KWh. I have read the efficiency is not high on this type of outlet. How much power am I really using? More like 9-10KWh?
2. If the car is charged and the charger is still plugged in, is it drawing any power?
3. If the charger is plugged into the wall but NOT plugged into the car, does it draw power? I've heard it is best to leave them plugged in instead of constantly plugging/unplugging from wall.
 

Sophias_dad

Supporting Member
Supporting Member
Jul 29, 2018
1,481
1,506
Massachusetts
1. probably like 10kwh. 108/109V is a sign of a bad-ish connection. I'm surprised your freezer can run on 4 amps, and I'd be a little concerned if it can start its compressor when the Y is plugged in and using 8 amps.
2. No, except when it periodically reactivates the charger to top-up the battery.
3. Yes, there are a few lights on it and it has to be powered up enough to activate the charge handle's button and transmitter to open the chargeport door, and that power has to come from somewhere. But no, its not much power.

Have you checked what your actual electricity rate is? The average in NC seems to be 10-11 cents/kwh which is pretty low.
 

Wolfpacker83

Member
May 5, 2021
149
99
NC
1. probably like 10kwh. 108/109V is a sign of a bad-ish connection. I'm surprised your freezer can run on 4 amps, and I'd be a little concerned if it can start its compressor when the Y is plugged in and using 8 amps.
2. No, except when it periodically reactivates the charger to top-up the battery.
3. Yes, there are a few lights on it and it has to be powered up enough to activate the charge handle's button and transmitter to open the chargeport door, and that power has to come from somewhere. But no, its not much power.

Have you checked what your actual electricity rate is? The average in NC seems to be 10-11 cents/kwh which is pretty low.
Yes, the rate is 10-11 cents/kwh. I've been charging an average of 8-10 KWh each day based on my driving habits... so I was trying to calculate how much my electric bill would go up. I got a mid-month projection from Duke Energy today stating my bill was on track to be $85 higher than last month. Some of that is obviously the car, but I think the rest is increased AC due to heat and we've been off work more and at home with the kids.
 

ffeingol

Member
Apr 18, 2021
23
11
Earth
If you want to track your effencicy in charging you can try a app like Optiwatt or an application like TeslaMate (teslamate.org). I'm charging on 110 right now and I get between 70 - 80% efficiency. I hope to have a 14-50 installed later this summer and 220v charging is more efficient.
 

Wolfpacker83

Member
May 5, 2021
149
99
NC
I keep it at 81% and got down to 60% this morning. It has been plugged in since 1PM and is up to 68%. It says I have 12 more hours to go... Brutally slow. It takes so long to charge I'm worried my power bill will be brutal. But I guess it isn't drawing that much to start with.
 

Sophias_dad

Supporting Member
Supporting Member
Jul 29, 2018
1,481
1,506
Massachusetts
It takes so long to charge I'm worried my power bill will be brutal.
8amps at 120V is just under 1kw, so your 12 hours will cost $1.20 and give you 12kw(36-48 miles), which would cost you at least $3.00 even on an efficient car, and probably more like $6-9 on an ICE car with similar-ish performance.

So stop worrying.
 

Wolfpacker83

Member
May 5, 2021
149
99
NC
8amps at 120V is just under 1kw, so your 12 hours will cost $1.20 and give you 12kw(36-48 miles), which would cost you at least $3.00 even on an efficient car, and probably more like $6-9 on an ICE car with similar-ish performance.

So stop worrying.
Yeah that's what I figured. Still debating whether to install a 240V or not.
 

Sophias_dad

Supporting Member
Supporting Member
Jul 29, 2018
1,481
1,506
Massachusetts
Still debating whether to install a 240V or not.
If you can do it yourself, its probably not a bad idea.

If you have to pay an electrician, unless you NEED more charge rate than you have, the minor inefficiency of 120V charging will take VERY long to justify the payoff to the electrician. Lets suppose you'd get 10% more efficiency by getting the 240V outlet. Now your cost to go 12,000 miles per year will go from (12000/4)=3000kwh=$300 per year to $270 per year. $30 per year(admittedly, its probably more like $400 turning into $360, but whatever.. Even doing it yourself will cost you years of electricity savings.
 

JohnC-PA

Member
May 18, 2021
48
121
Cranberry Township, Pennsylvania
I believe that 1kw of charge should give you about 4 miles of travel distance. Here in PA, I am paying 12.3 cents per kw, so I would be paying about 3 cents per mile. You would be paying slightly less than that in NC if I am reading the thread correctly.
 

Wolfpacker83

Member
May 5, 2021
149
99
NC
If you can do it yourself, its probably not a bad idea.

If you have to pay an electrician, unless you NEED more charge rate than you have, the minor inefficiency of 120V charging will take VERY long to justify the payoff to the electrician. Lets suppose you'd get 10% more efficiency by getting the 240V outlet. Now your cost to go 12,000 miles per year will go from (12000/4)=3000kwh=$300 per year to $270 per year. $30 per year(admittedly, its probably more like $400 turning into $360, but whatever.. Even doing it yourself will cost you years of electricity savings.
Looking at it that way, it wouldn't be worth it. I only drive 6-7K a year.
 

AlexHung

Member
Mar 13, 2021
305
286
Santa Cruz, CA
At 120/8A I'm getting between 2-3 mi/h charge rate.
I really don't think using mi/h as a measurement unit is useful because how we drive and the conditions of the drive affect how much range we can get out out the energy. For my example, the last charge I did at home took 8 hour 7 min and added 7.1 kWh to the battery. That's 76% efficiency as reported by the car (from both TazLab and Optiwatt).
 

brkaus

Well-Known Member
Jul 8, 2014
8,048
6,526
Austin, TX
There are many plug in power meters rated for standard outlets that will give you the exact measurement. I use a kill-a-watt for measuring various appliances around my house.
 

jcanoe

Active Member
Oct 2, 2020
3,262
3,240
Maryland
Is there a chance you could charge at your workplace? I charge at a public Level 2 charging station (200V/30A, good for 6kW) between an hour and 90 minutes most days. I can charge at home but I am at the shopping center for at least an hour most mornings so I take advantage of the free parking, charging.

If you find that charging at home using Level 1 (120V/8A) is taking too long know that there are options. You don't necessarily need to install a 240V/50A circuit. A 240V/20A circuit would be significant upgrade to your home charging, be 4X faster what you are able to achieve with your current charging setup. 240V charging would be almost twice as efficient as charging at 120V (~90% for 240V versus ~80% to 83% for 120V.)
 
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Sophias_dad

Supporting Member
Supporting Member
Jul 29, 2018
1,481
1,506
Massachusetts
8 hour 7 min and added 7.1 kWh to the battery. That's 76% efficiency
I'm not debating efficiency of charging. I was referring to a slightly earlier poster who was stating that 1kwh is enough for 4 miles. It might be, if you are driving at 40mph with the AC and heater turned off.

120/8amp should be 960 watts, and 75% of that is 720w. in order to get 3.7mi out of 720wh, you gotta be getting 194wh/mi. Its probably POSSIBLE, but you are ignoring any parasitic losses and any HVAC usage, and your probably gonna have to drive 30mph.
 
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AlexHung

Member
Mar 13, 2021
305
286
Santa Cruz, CA
I'm not debating efficiency of charging. I was referring to a slightly earlier poster who was stating that 1kwh is enough for 4 miles. It might be, if you are driving at 40mph with the AC and heater turned off.

120/8amp should be 960 watts, and 75% of that is 720w. in order to get 3.7mi out of 720wh, you gotta be getting 194wh/mi. Its probably POSSIBLE, but you are ignoring any parasitic losses and any HVAC usage, and your probably gonna have to drive 30mph.
I just double check with the car. I’m actually charging at 10A. My bad.
 

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