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Hi All,

I have had a Bolt for about 3 months now, I drive about 1800 miles a month..My electricity usage has gone up by around 1,000KWh per month..Much more than I expected. I had a NEMA 14 50 outlet installed in my Garage, and got some generic charger off of eBay. Are there differences in the efficiencies of Chargers?

Any ideas why the car would be consuming so much electricity to charge?
 

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The average around here seems to be around 4 miles per kWh from the battery. Perhaps 10% more energy is taken from the wall compared to what is delivered by the battery, so that would be 3.6 miles per kWh from the wall. Your numbers suggest 1.8 miles per kWh, or about half of what is typical.

The device you purchased on Ebay is likely an EVSE, which is not a charger. It's essentially an intelligent extension cord. There is no way it could be consuming half the electricity without bursting into flames. We can fairly safely rule this out as the culprit.

You didn't mention how far you drive, how fast, what the temperature and conditions are, so we have no idea what a reasonable efficiency for your conditions are.

Electricity usage normally goes way up in winter months for most household, so if you are comparing the past 3 months with the 3 months prior to that, it's likely a very inaccurate way to determine how much extra electricity you consume. You'd need to compare the past 3 months to the same months last year, and even that is not necessarily accurate given the variability of consumption.

You'd really need to measure your consumption from the wall to paint an accurate picture of efficiency. The car should display your average miles per kWh from the battery.
 

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I am doing 4 km / kWh in a very moderate climate (7 deg C or so) with a not to lame driving style. 1800 miles is approx. 2900 km, which would mean 725 kWh. If it is much colder where you are and/or you are driving even sportier, then 1000 kWh for 1800 miles might not be out of bounds, I guess.

The charger you are talking about is effectively just a switch. The efficiency part is in the car, so should not be affected by your choice of 'charger'. Unless you are using very, very long and thin wires to hook it up ;-)

edit - that was already said, I see now ...
 

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Not sure what part of the world you're from but if it has been cold where you are and you leave your Bolt plugged in when parked at home, did you account for the electricity it uses to keep the battery warm?
 

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Hi All,

I have had a Bolt for about 3 months now, I drive about 1800 miles a month..My electricity usage has gone up by around 1,000KWh per month..Much more than I expected. I had a NEMA 14 50 outlet installed in my Garage, and got some generic charger off of eBay. Are there differences in the efficiencies of Chargers?

Any ideas why the car would be consuming so much electricity to charge?
My usage went up after the first 6 months, and I'm certain it's all down to the weight of my right foot. There is a huge difference in efficiency between 65 and 75 MPH. You don't have to go much faster on the freeway to crater your miles/kWH value.
 

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Hoping the OP shares some more info, otherwise the speculation is mostly pointless.

There is a huge difference in efficiency between 65 and 75 MPH. You don't have to go much faster on the freeway to crater your miles/kWH value.
This just gave me the idea of creating a display for either an EV or gasomobile that shows estimated range given current speed, and then shows other estimated ranges given 5, 10, or 15 MPH slower than current speed. It would highlight to the driver just what it means that aerodynamic drag increases with the square of speed.

That said, I would be inclined to drive as quickly as was safe, and not likely to draw attention from LEOs if I owned an EV. Electricity is about 2 cents per mile here, which would still be cheap if I was paying 3 cents instead. I pay 6 cents per mile in the Prius, and 11 cents in the 30 MPG Acura.
 

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Hoping the OP shares some more info, otherwise the speculation is mostly pointless.



This just gave me the idea of creating a display for either an EV or gasomobile that shows estimated range given current speed, and then shows other estimated ranges given 5, 10, or 15 MPH slower than current speed. It would highlight to the driver just what it means that aerodynamic drag increases with the square of speed.

That said, I would be inclined to drive as quickly as was safe, and not likely to draw attention from LEOs if I owned an EV. Electricity is about 2 cents per mile here, which would still be cheap if I was paying 3 cents instead. I pay 6 cents per mile in the Prius, and 11 cents in the 30 MPG Acura.
It could just be an option to the GOM. It's doing something similar now, just with less clarity on what the high and low values mean.

I certainly wouldn't suggest going significantly slower than the flow of traffic, simply to gain higher efficiency. Sadly, we have had many low range EV drivers in the HOV lane here, that trundle along at 10 under the speed limit to preserve their range. In the thick of commute hours, it's not noticeable, but around the edges, when the HOV lane can still do 65, a road boulder doing 50-55 gets people plenty worked up. I haven't commuted in a long time, but I hear from folks that do :)
 

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An easier number to work with would be how much %SOC is left before you charge. For me, I routinely use 50% of my EV range (ignoring miles/kWh) so every night I put back in 30 kWh. Assume a Mon-Fri work week, 4 weeks/month, that's 20 commute days. So roughly 20 * 30 kWh = 600 kWh. Assume 90% efficiency on L2 charging so you're actually putting in 600 / 0.9 = 667 kWh in your Bolt.

My bill shows an increase of 800 kWh. So I forgot about some shopping and weekend jaunts and cold weather TMS when charging and preconditioning. Slack of 133 kWh doesn't seem too bad to me.

Your turn OP to run the numbers.
 

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This just gave me the idea of creating a display for either an EV or gasomobile that shows estimated range given current speed, and then shows other estimated ranges given 5, 10, or 15 MPH slower than current speed. It would highlight to the driver just what it means that aerodynamic drag increases with the square of speed.
The Bolt display has trend bars which show whether you are doing better or worse than the estimate and by how much. This seems to be what you are asking for.
 

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not my picture, representative only. i'm jealous of the range estimate though!
Holy cow, you weren't kidding about the GOM!
 

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Just a comparison, my hot tub was 2x the electricity than my bolt was at 3000 miles a month
 

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Just a comparison, my hot tub was 2x the electricity than my bolt was at 3000 miles a month
How are you measuring this?

3000 miles a month in the Bolt would be about 750 kWh. Twice that would be 1500 kWh for your hot tub. From what I've read, most people consume around 500 kWh or less a month for their hot tub. Yours would be more than 3x typical.
 

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Is That based in Florida? I am in cold climate in Nebraska. I got hot tub 4 years before the car. It gets cold in Nebraska. Where is your data from?
 

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Is That based in Florida? I am in cold climate in Nebraska. I got hot tub 4 years before the car. It gets cold in Nebraska. Where is your data from?
Mostly based on this thread where people report from 200-600 kWh.

https://www.poolspaforum.com/forum/index.php?/topic/27122-average-kwh-to-operate-a-tub/


Also from this statement:

Your 310 kWh in 29 days represents slightly less than half a kilowatt per hour over that period, which is the energy necessary to compensate for a temperature drop of a bit under 1/2 degree per hour in a 400-gallon spa. Seems like a reasonable ballpark figure to me. (Back-of-the-envelope math: 400 gallons of water is about 3,300 pounds. It takes one BTU to heat a pound of water one degree F, and a kilowatt-hour is roughly equivalent to 3,400 BTU. Therefore it takes a tad under one kilowatt-hour of energy to raise the temperature one degree in a 400-gallon tub. 29 days = 696 hours. 310 divided by 696 = 0.45 kilowatts every hour, 24 hours per day, for 29 days, on average.)"

With the cost of electricity at 15 cents a kilowatt/hour, the hot tub is costing $46.50 a month or $558 per year.
1,500 kWh at 10 cents which is about average, would be $150 a month in electricity for a hot tub.
 
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