Hmm, the numbers don't seem to add up.scottt said:Well, my first month of ownership data is in.
Drove a little over 500 miles. $1.50 in electricity costs.
scottt said:Well, my first month of ownership data is in.
Drove a little over 500 miles. $1.50 in electricity costs.
Um, WOW!
Such a calculation will be roughly correct, but remember that what the car indicates as "energy consumed" only measures what came "out of" the battery. But, this amount is different (less) than what was "put into" the battery when charging it.campfamily said:I'm currently averaging about 245 wH/mi, which means for 500 miles, I would have used about 120 kwH. At $0.11 per kwH, that works out to about $13.
WattsUp said:Such a calculation will be roughly correct, but remember that what the car indicates as "energy consumed" only measures what came "out of" the battery. But, this amount is different (less) than what was "put into" the battery when charging it.campfamily said:I'm currently averaging about 245 wH/mi, which means for 500 miles, I would have used about 120 kwH. At $0.11 per kwH, that works out to about $13.
This is because the charging process is not 100% efficient (it is more like 80-90% efficient) so, in the end, the car's measurement of energy consumed from the battery only accounts for 80-90% of the energy that was actually required "from the wall". In other words, the car's numbers do not include the "charging overhead".
So, using only the car's measurements, you will need to inflate your numbers by 10-20% (roughly approximating the charging overhead) to more truly estimate the amount of energy consumed -- and thus get closer to the true cost.
Better still is to use an external measure, such as a Kill-A-Watt device, to determine how much electricity was consumed from the wall when charging the car. This will account for any charging overhead (and will do so precisely) since it will naturally be included in the measurement.
Haha.. thanks, yeah. I fixed it.campfamily said:BTW, I think you also slipped a decimal point in your post (which you submitted while I was typing mine!!! LOL). Isn't $1.50 / 158 equal to ~$.01, not ~$.001?
WattsUp said:Hmm, the numbers don't seem to add up.scottt said:Well, my first month of ownership data is in.
Drove a little over 500 miles. $1.50 in electricity costs.
To drive 500 miles in the FFE, I estimate you would need about 158 kWh:
(500 miles / 76 mile range) * ~24 kWh used per charge = ~158 kWh
$1.50 / 158 kWh = ~$0.01 cents per kWh
So, how are you paying $0.01 per kWh? Are you doing a lot of free charging?
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