# Total Charging cost based on kWh added, not kWh used ?

I have seen this question asked, but I didn’t see any answer on any of the threads where it was asked.

For HOME charging, the Total Charging Cost seems to be based on the kWh added to the battery, not the kWh used by the charger …. This seems like a flawed calculation.

I have a v3 wall connector, and I can see the watts used by the charger through the API, and it matches almost exactly (within 1 kWh over the course of a month) to the “kWh used” as reported by TeslaFi.

My electric bill will reflect the kWh used, not the kWh added - so in my mind, TeslaFi should change the logic. Otherwise all of the data collection is for nothing, considering that the financial calculation is off by ~25%.

Knowing how much electricity my car theoretically would have consumed under ideal conditions without any losses is not a valuable thing to know …. Knowing how much money I actually spent on electricity for my car is in fact exactly why I am using TeslaFi - and now it turns out this isn’t even what it is telling me.

Customer support service by UserEcho

Totally agree that all the financial numbers tracked within TeslFi are wack (don't add up). As such, I decided to track three sets of figures.

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TOTAL COST- Each month, I add up all the charge costs and subtract this amount from my monthly electric bill as the total cost for the car.--

TRIP COST- Next, I add up all the individual drive costs (trip costs) and use this figure to calculate the car's cost per mile. Accounts for 70.39% of total costs.--

VEHICLE OVERHEAD- Finally, I subtract the trip cost figure from the total cost figure and consider this the cost for all the overhead (range loss). For instance, using AC or heating, windshield wipers, lights at night, sentry camera use, phantom drain, battery conditioning, etc. Although I've only had the car for three weeks, this figure is running about 29.61% of the total costs.