Total efficiency Tesla Model 3

On the Dutch version of this blog, I got 5 days ago following question from Jacquelines Stals at blog post “Efficiency when home charging at 11kw“:

Hello Frank, thanks for the interesting blogs and especially those about the charging efficiency of the M3 LR. I have been driving that car for over a year and can derive a charge loss of approx. 11% from my data: 6,158 kWh charged (60% at home with three-phase, 25% at SuC and the rest at other fast chargers and public charging stations). Total consumption of the car: 5,510 kWh. Do you think this range of charging loss is “normal”?

I found this an interesting question to delve deeper into based on the data that I have collected with TeslaFi over the past 2 years. When I look at the data, I can see different types of losses that all together fall under the denominator Phantom Drain:

• when the car is asleep
• losses when the car is parked, but has not yet fallen asleep
• Sentry Mode (surveillance mode – processing camera images and saving “suspicious” events to a USB stick / USB hard drive)
• activation of climate control for pre-conditioning the cars interior and – in case activated – interior protection; such as pre-heating interior and battery at low temperatures, and activating air conditioning before departure on hot days

Charging losses with AC charging.
In the blog post “Efficiency when home charging at 11kw” I had already calculated and described that charging losses are about 3,5% when AC charging at 11 kW.

Charging losses with DC charging.
Tesla Superchargers and fast chargers from, for example, FastNed, Ionity and Shell Recharge are so-called DC chargers. These chargers charge your Tesla with direct current, so that the energy goes directly from the charger into your battery – no conversion necessary from AC to DC. I could find little well-founded information about losses when DC charging a Tesla Model 3, so I used my own data from TeslaFi. Looking my fast charging over 2020, I see that I’ve only used Tesla Superchargers and the free Lidl fast chargers at the shopping mall close to my home. I only have the provided kWh data from the Tesla Supercharger sessions. From all the charging sessions where TeslaFi collected data, I see the following figures: according to Tesla I have charged 449 kWh, TeslaFi indicates that 439.94 kWh has been received, and lastly TeslaFi indicates that of that 431.00 kWh was stored in the battery. This means that there is a total of 4.0% of charging losses when DC fast-charging, of which 2.0% is lost from Tesla Supercharger to my Tesla Model 3 charging port, and another 2.0% from charging port to the battery. The losses with DC charging are therefore comparable to the losses seen when doing AC charging.

Phantom Drain.
To find an approximation for Phantom Drain, I delved into the data on TeslaFi. There is no way – at least not know to me – to get the amount of Phantom Drain as a report out of TeslaFi. So it becomes a manual exercise to get numbers per day out of TeslaFi. In order not to re-enter 365 days of data into an Excel-sheet and still arrive to a reasonably good average with a smaller data set, I used the months January 2020, April 2020, July 2020 and October 2020. These months has a representation for each season, plus there is a month in which we have been on vacation for 2 weeks and when being on holiday we use more frequently Sentry Mode.
When I add up the Phantom Drain for the aforementioned 4 months, 175.3kWh has been consumed in these 123 days. That means an average loss of 1.42 kWh / day. With 365 days in a year, the annual Phantom Drain is 518 kWh!

Approximate annual loss on a Tesla Model 3 LR AWD.
When we put all together in the table below, we see following result:

kWh added	Gross	Nett	Losses
– AC charging	4,533 kWh	4,375 kWh	3.5%
– DC charging	1,224 kWh	1,175 kWh	4.0%
kWh added	5,757 kWh	5,550 kWh	207 kWh
Losses
– charging losses			207 kWh
– Phantom Drain			518 kWh
Total losses			725 kWh
Losses in %	12.6%

Conclusion.
Most of the losses come from Phantom Drain, and this is more than I had expected. With the 11% loss that Jacq Stals reported he is achieving better results than what I achieved with my Tesla Model 3 LR AWD (March 2019).