If someone uses your referral link when ordering a new Tesla vehicle, you get "1000 miles" of free supercharging when the vehicle is delivered to them, which is valid for 6 months from when you receive it. To me, this never made sense because superchargers are billed by unit of energy (in kWh), at least in CA. So getting "1000 miles" didn't really mean much to me. How do these "miles" magically convert into kWh when they are used?
To answer this question, I ran an experiment. For my most recent "1000 mile" referral I received this past June, I recorded each supercharging session and the "miles" it consumed. I did not have any referral credit prior, and did not have any credit after. (e.g. using pay-per supercharging before and after the referral).
The data points:
1. (6/26) Supercharger A - 62.0 kWh: 158 miles used = 2.55 mi/kWh
2. (7/5) Supercharger B - 54.5 kWh: 140 miles used = 2.57 mi /kWh
3. (7/9) Supercharger C - 53.2 kWh : 138 miles used = 2.59 mi /kWh
4. (7/17) Supercharger C - 55.3 kWh : 143 miles used = 2.59 mi /kWh
5. (8/5) Supercharger C - 24.2 kWh : 65 miles used = 2.69 mi / kWh
6. (8/8) Supercharger C - ?? (46.41) kWh : 113 miles used = ?? mi / kWh
7. (9/4) Supercharger D - 55.8 kWh : 153 miles used = 2.74 mi / kWh
8. (9/11) Supercharger E - 37.18 kWh : 93 miles used = 2.51 mi / kWh
Retrieving "miles" consumed is easy: Tesla provides this info on their website under the "Charging' tab once logged in to your Tesla account. I retrieved the "miles" consumed for each of the 8 charging sessions above via my Tesla account.
Calculating the total miles consumed is also easy, simply add them all up: 158 + 140 + 138 + 143 + 65 +113 + 153 + 93 = "1003 miles" consumed. This is right on target with what Tesla promised for the referral.
For that 8th charging session, I actually ran out of "miles" referral credit part way during the charging session, so I was charged (per kWh) for the remaining balance. In this specific case, Tesla's invoice showed both the total kWh delivered by the supercharger, plus the portion of kWh charged to my credit card. So it made it very easy to back calculate how many kWh was consumed for the "93 miles" of referral credits used in that session.
But for all the other supercharging sessions (#1-7), Tesla does not generate an Invoice, nor show consumed energy (kWh) on their website. It simply says "Credits used XXX miles" per session. So how did I retrieve them?
Teslamate!
Teslamate uses Tesla's API to directly retrieve data about the vehicle, including charging data. Unfortunately, I do believe that that charging session data Teslamate retrieves and displays is energy (in kWh) delivered to the vehicle, rather than dispensed by the supercharger. I don't think Tesla makes available in a public API the energy dispensed by the supercharger. The only place that shows that is in the Invoice after a charging session, but already clarified that it's not generated for a free session. Nonetheless, it's a fair good representation of the energy consumed.
One caveat: you can see in the table above that energy consumed is missing for charging session # 6. Unfortunately, Teslamate only retrieved the data for the charging session partway, so I did not include the partial data in the table. However, we can calculate an average mi / kWh rate for the rest of the 7 sessions (2.60 mi /kWh), and back calculate the energy consumed for that session. The result is 46.41 kWh.
Adding all the energy consumed together, we get: 62.0 + 54.5 + 53.2 + 55.3 + 24.2 + 46.41 + 55.8 + 37.18 = 388.59 kWh consumed.
This is close to the 400 kWh others have touted. We also have to keep in mind that charging session #6 was estimated, and also these values are energy delivered to the vehicle. So 3% less than expected is within error.
To summarize:
- 8 charging sessions
- "1003 miles" consumed
- 388.59 kWh consumed (by the vehicle)
- 2.60 mi / kWh average conversion rate
So the next time you receive "1000 miles" of free supercharging credit, consider it 400 kWh! I don't know why Tesla obfuscate this, but perhaps there's a legal reason why they can't just say "400 kWh" of free energy credit. (e.g. tax implications?)
Note: this experiment was run on a Model Y, so it's possible that the mi / kWh conversion rate may not translate to other Tesla vehicles (and thus I posted it in MY forum).
To answer this question, I ran an experiment. For my most recent "1000 mile" referral I received this past June, I recorded each supercharging session and the "miles" it consumed. I did not have any referral credit prior, and did not have any credit after. (e.g. using pay-per supercharging before and after the referral).
The data points:
1. (6/26) Supercharger A - 62.0 kWh: 158 miles used = 2.55 mi/kWh
2. (7/5) Supercharger B - 54.5 kWh: 140 miles used = 2.57 mi /kWh
3. (7/9) Supercharger C - 53.2 kWh : 138 miles used = 2.59 mi /kWh
4. (7/17) Supercharger C - 55.3 kWh : 143 miles used = 2.59 mi /kWh
5. (8/5) Supercharger C - 24.2 kWh : 65 miles used = 2.69 mi / kWh
6. (8/8) Supercharger C - ?? (46.41) kWh : 113 miles used = ?? mi / kWh
7. (9/4) Supercharger D - 55.8 kWh : 153 miles used = 2.74 mi / kWh
8. (9/11) Supercharger E - 37.18 kWh : 93 miles used = 2.51 mi / kWh
Retrieving "miles" consumed is easy: Tesla provides this info on their website under the "Charging' tab once logged in to your Tesla account. I retrieved the "miles" consumed for each of the 8 charging sessions above via my Tesla account.
Calculating the total miles consumed is also easy, simply add them all up: 158 + 140 + 138 + 143 + 65 +113 + 153 + 93 = "1003 miles" consumed. This is right on target with what Tesla promised for the referral.
For that 8th charging session, I actually ran out of "miles" referral credit part way during the charging session, so I was charged (per kWh) for the remaining balance. In this specific case, Tesla's invoice showed both the total kWh delivered by the supercharger, plus the portion of kWh charged to my credit card. So it made it very easy to back calculate how many kWh was consumed for the "93 miles" of referral credits used in that session.
But for all the other supercharging sessions (#1-7), Tesla does not generate an Invoice, nor show consumed energy (kWh) on their website. It simply says "Credits used XXX miles" per session. So how did I retrieve them?
Teslamate!
Teslamate uses Tesla's API to directly retrieve data about the vehicle, including charging data. Unfortunately, I do believe that that charging session data Teslamate retrieves and displays is energy (in kWh) delivered to the vehicle, rather than dispensed by the supercharger. I don't think Tesla makes available in a public API the energy dispensed by the supercharger. The only place that shows that is in the Invoice after a charging session, but already clarified that it's not generated for a free session. Nonetheless, it's a fair good representation of the energy consumed.
One caveat: you can see in the table above that energy consumed is missing for charging session # 6. Unfortunately, Teslamate only retrieved the data for the charging session partway, so I did not include the partial data in the table. However, we can calculate an average mi / kWh rate for the rest of the 7 sessions (2.60 mi /kWh), and back calculate the energy consumed for that session. The result is 46.41 kWh.
Adding all the energy consumed together, we get: 62.0 + 54.5 + 53.2 + 55.3 + 24.2 + 46.41 + 55.8 + 37.18 = 388.59 kWh consumed.
This is close to the 400 kWh others have touted. We also have to keep in mind that charging session #6 was estimated, and also these values are energy delivered to the vehicle. So 3% less than expected is within error.
To summarize:
- 8 charging sessions
- "1003 miles" consumed
- 388.59 kWh consumed (by the vehicle)
- 2.60 mi / kWh average conversion rate
So the next time you receive "1000 miles" of free supercharging credit, consider it 400 kWh! I don't know why Tesla obfuscate this, but perhaps there's a legal reason why they can't just say "400 kWh" of free energy credit. (e.g. tax implications?)
Note: this experiment was run on a Model Y, so it's possible that the mi / kWh conversion rate may not translate to other Tesla vehicles (and thus I posted it in MY forum).
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