calculating cost of electricity used

Chevy Spark EV Forum

Help Support Chevy Spark EV Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

danev

New member
Joined
Aug 20, 2019
Messages
3
Newbee here, considering purchasing used 2016 Spark EV. I'm no pro when it comes to electricity or math. So I have a couple questions regarding calculating electricity used and cost per mile to drive a Spark EV: :?

1. I live in Seattle where residential electricity runs about 8 cents per KwH. Assuming that the Spark battery starts at 19 KwHs, I assume that to fully charge (assuming the battery is down to zero miles when charge which I realize rarely happens) will require 19KwHs? correct? Based on that assumption, I come up with this -- 19KwH x 0.8 = $1.44 to fully charge battery. Correct?

2. If above assumptions & calculation is correct, assuming 80 miles range on a full charge cost per mile would be $0.018/mile (18 cents). Yes?

3. Can most Chevy dealerships provide an accurate estimate of remain KW of battery?
 
danev said:
Newbee here, considering purchasing used 2016 Spark EV. I'm no pro when it comes to electricity or math. So I have a couple questions regarding calculating electricity used and cost per mile to drive a Spark EV: :?

1. I live in Seattle where residential electricity runs about 8 cents per KwH. Assuming that the Spark battery starts at 19 KwHs, I assume that to fully charge (assuming the battery is down to zero miles when charge which I realize rarely happens) will require 19KwHs? correct? Based on that assumption, I come up with this -- 19KwH x 0.8 = $1.44 to fully charge battery. Correct?

2. If above assumptions & calculation is correct, assuming 80 miles range on a full charge cost per mile would be $0.018/mile (18 cents). Yes?

3. Can most Chevy dealerships provide an accurate estimate of remain KW of battery?

1. You would want to assume you only get 75% of the energy from the cord into the car to be conservative on your estimates for power consumption (this would be a level one charger). So assume it will take 24kWs to charge your 19kWh battery pack if it was completely drained. So 24 x .08 = $1.92 per full charge or per 80 miles.

2. If you are assuming an 80 mile range and calculating based off of $1.92 you would be looking at $1.92/80 = .024 This is 2.4 cents per mile. The calculations with the usage I am getting from mine is closer to 1.7 cents per mile but my range is higher and my electricity is cheaper.

3. Probably not. If you buy a USB dongle and get the torque pro app with the bolt PIDS loaded you could get that information for less than $20.
 
danev said:
Thanks Kermit. One other newby question: What are PIDs

They are Parameter IDs that can be accessed by having an OBD2 adapter connected. If you search for Torque Pro or Bolt PIDs you should be able to find what you need.
 
I just look at my electric meter every morning about the same time, and know how many KWh I typically use on days when I'm NOT charging the car. Then on a day when I have been charging the car all night I know about how many more KWh were used to charge the car. I pay $0.11 per KWh here in Phoenix (on my particular plan). Not that scientific, but I have a good idea of what I spend to charge it, which is significantly less than buying gas.
 
BetteInSCW said:
I just look at my electric meter every morning about the same time, and know how many KWh I typically use on days when I'm NOT charging the car. Then on a day when I have been charging the car all night I know about how many more KWh were used to charge the car. I pay $0.11 per KWh here in Phoenix (on my particular plan). Not that scientific, but I have a good idea of what I spend to charge it, which is significantly less than buying gas.
If you are using the 120 VAC L1 EVSE that came with the car, you can purchase a KILL-A-Watt EZ power meter for about $30 and use it to measure the actual number of kWhs going to your car. You will find that the AC/DC converter in the car is only about 75% efficient at 120 VAC. So 100 watts at the wall = 75 watts into the battery. A 240 VAC single phase L2 EVSE is about 85% efficient.
 
At approximately 13 cents per kwh and average of 4.6 mi per kwh. My cost is 3 cents per mile. I drive about 100 miles per week so it cost me $3 per week and $12 per month.
 
Limesparklover said:
At approximately 13 cents per kwh and average of 4.6 mi per kwh. My cost is 3 cents per mile. I drive about 100 miles per week so it cost me $3 per week and $12 per month.

My PG&E rate is currently $0.23 per kWh and goes up quickly if I exceed the daily baseline rate. At 75% L1 charging efficiency, my true rate is almost $0.31 per kWh. Fortunately, I have solar panels on my home and they keep me below the baseline usage limits.
 
Back
Top