EV and My Commute
If you read my analysis of the commute blogpost, one of the pieces that I had to guess about was the multiplier of battery usage. Essentially, I was guessing that going uphill would use 2 times as much battery and going downhill would use 1/2 the battery.
I was wrong on my predictions, but in my defense, I was about to spend several thousand dollars and I did not want to be wrong, so I was conservative with some of my predictions. I want to go back and look at them and refine the multipliers due to elevation and also add some in for some other pieces as well.
Let me define what I mean by multiplier. When I drive 1 mile, I expect that the battery level of miles left will drop by 1 mile. That is not always the case. In fact, that is rarely the case. Every commute is different and most people do not drive an electric car or do not have a commute that is as close to the EPA mileage rating of the car. My commute is 80 miles. That is close to the 83-mile range for a Nissan Leaf (pre-2017) of Volkswagen egolf. but it is close enough to the Kia Soul 93-mile range and the Nissan Leaf 107-mile range that math was completed. My multiplier is the number that I can multiply by the actual miles I drive, to get the battery range decrease during that range. Example: If I drive 10 miles and it only registers a 5 mile drop in battery, then the multiplier is 0.5, because 10*0.5=5.
I know this has subjectivity as the reported range of the car changes due to how you drive. That is why I took the average over the first 2 weeks of my commute. Oddly, the numbers did not vary much (1 mile per section)
After graphing, it made more sense to see how the multiplier deviated from 1. If 1 is normal, then the change from normal might show something different. Here is the graph that I created for % grade versus multiplier change
Yes, %Grade (blue) changes the multiplier (red). Driving uphill requires more battery and driving downhill requires less battery.
Please remember that these numbers are on a highway that does not usually exceed 50mph, it is a winding road. Here is more information on the road
Based on the driving conditions mentioned above, here is my graph of % grade versus multiplier. The equation is that of the trendline. If you add the % grade for your commute in for X, you will get the multiplier for your drive. The R2 value means that this is a good estimate (an R2 of 1 is perfect data and 0.5 is flipping a coin would be as accurate).
So, to get a good estimation of how your range is affected by your commute; here is your equation.
Range = Miles*(0.3*Grade+0.76)
I am not sure how speed will affect this beyond, going faster will take more battery.
To use this chart and equation to look at my commute. My average values for commute range distance is:
To Work - 25.3 miles range
To Home - 37.8 miles range
Total - 63.1 miles of range total reported by the car.
Using the Equation, the range reported distance is as follows:
To Work - 22.9 miles range
To Home - 38.6 miles range
Total - 60.8 miles of range total predicted by the equation.
2.3 miles of difference.
I was wrong on my predictions, but in my defense, I was about to spend several thousand dollars and I did not want to be wrong, so I was conservative with some of my predictions. I want to go back and look at them and refine the multipliers due to elevation and also add some in for some other pieces as well.
Let me define what I mean by multiplier. When I drive 1 mile, I expect that the battery level of miles left will drop by 1 mile. That is not always the case. In fact, that is rarely the case. Every commute is different and most people do not drive an electric car or do not have a commute that is as close to the EPA mileage rating of the car. My commute is 80 miles. That is close to the 83-mile range for a Nissan Leaf (pre-2017) of Volkswagen egolf. but it is close enough to the Kia Soul 93-mile range and the Nissan Leaf 107-mile range that math was completed. My multiplier is the number that I can multiply by the actual miles I drive, to get the battery range decrease during that range. Example: If I drive 10 miles and it only registers a 5 mile drop in battery, then the multiplier is 0.5, because 10*0.5=5.
I know this has subjectivity as the reported range of the car changes due to how you drive. That is why I took the average over the first 2 weeks of my commute. Oddly, the numbers did not vary much (1 mile per section)
After graphing, it made more sense to see how the multiplier deviated from 1. If 1 is normal, then the change from normal might show something different. Here is the graph that I created for % grade versus multiplier change
Yes, %Grade (blue) changes the multiplier (red). Driving uphill requires more battery and driving downhill requires less battery.
Please remember that these numbers are on a highway that does not usually exceed 50mph, it is a winding road. Here is more information on the road
Based on the driving conditions mentioned above, here is my graph of % grade versus multiplier. The equation is that of the trendline. If you add the % grade for your commute in for X, you will get the multiplier for your drive. The R2 value means that this is a good estimate (an R2 of 1 is perfect data and 0.5 is flipping a coin would be as accurate).
Range = Miles*(0.3*Grade+0.76)
I am not sure how speed will affect this beyond, going faster will take more battery.
To use this chart and equation to look at my commute. My average values for commute range distance is:
To Work - 25.3 miles range
To Home - 37.8 miles range
Total - 63.1 miles of range total reported by the car.
Using the Equation, the range reported distance is as follows:
To Work - 22.9 miles range
To Home - 38.6 miles range
Total - 60.8 miles of range total predicted by the equation.
2.3 miles of difference.
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