Ever wondered the true cost to fuel your Tesla? Well since getting my SR+, 4 months ago, I have been tracking the amount of electricity used by the car, using the TeslaFi application, and to my amazement it's not the 260 Wh/Mile that the car reports!
To my surprise the car consumes an average of 22.6% more electricity than it reports, so the 260 Wh/m reported is actually more like 336 Wh/m consumed!
How do I calculate these losses? Well if I charge the car to 100%, and drive the car for some miles, TeslaFi will give me the amount of energy taken from the battery to drive the car some miles. Now, if I charge the car back up to 100%, TeslaFi will tell how much energy consumed by the car to get back to 100% (by taking readings of volts & amps during the charging period). TeslaFi also gives the value of the energy supplied to the battery.
Note: TeslaFi also report lifetime values for this data and I have used that to get lifetime average figures.
Using this data, it is possible to calculate;
Overall efficiency ( Energy taken from by the battery / Energy consumed by the car)
Battery efficiency ( Energy taken from the battery / Energy supplied to the battery)
Charging efficiency (Energy supplied to the battery / Energy consumed by the car)
The car's true Wh/Mile (Energy consumed by the car / Miles driven)
Below is some data I have collected for the cars lifetime and for 3 separate days use;
It appears, that a high percentage of the losses can be attributed to battery losses. I.e. the difference between energy put into the battery and energy you get back out of the battery. Looking at the 25/01/22 data the battery losses are quite high at 22.1% and this might be down to the low temperature during that period?? I'll have to wait for warmer days to see if battery efficiency improves with higher temperatures...
Do you use TeslaFi (or other apps) to track usage? I'd be interested to see your overall efficiency of your car (Tesla or other brand)?
Any other thoughts about the cars efficiency??
To my surprise the car consumes an average of 22.6% more electricity than it reports, so the 260 Wh/m reported is actually more like 336 Wh/m consumed!
How do I calculate these losses? Well if I charge the car to 100%, and drive the car for some miles, TeslaFi will give me the amount of energy taken from the battery to drive the car some miles. Now, if I charge the car back up to 100%, TeslaFi will tell how much energy consumed by the car to get back to 100% (by taking readings of volts & amps during the charging period). TeslaFi also gives the value of the energy supplied to the battery.
Note: TeslaFi also report lifetime values for this data and I have used that to get lifetime average figures.
Using this data, it is possible to calculate;
Overall efficiency ( Energy taken from by the battery / Energy consumed by the car)
Battery efficiency ( Energy taken from the battery / Energy supplied to the battery)
Charging efficiency (Energy supplied to the battery / Energy consumed by the car)
The car's true Wh/Mile (Energy consumed by the car / Miles driven)
Below is some data I have collected for the cars lifetime and for 3 separate days use;
It appears, that a high percentage of the losses can be attributed to battery losses. I.e. the difference between energy put into the battery and energy you get back out of the battery. Looking at the 25/01/22 data the battery losses are quite high at 22.1% and this might be down to the low temperature during that period?? I'll have to wait for warmer days to see if battery efficiency improves with higher temperatures...
Do you use TeslaFi (or other apps) to track usage? I'd be interested to see your overall efficiency of your car (Tesla or other brand)?
Any other thoughts about the cars efficiency??
