Took delivery of my MY about 2 weeks ago. Been trying to figure out range info as what it looks to be is very disappointing info. This took me to a question of battery capacity as i was running scenarios at different Wi/Mile. While specs say 75 Kwh, many posts speak to "hidden capacity". I noticed on my Nikola app this AM that it is using 78 Kwh as capacity so I wrote an email to the developer. I was frankly a bit surprised when he (David) wrote back and explained how Nikola does the math based on data supplied by the car. He sent me a spreadsheet and walked me through the calcs. While he stopped short in saying the battery is 78 Kwh, the math indicates it is. I Google searched Model Y and 78 Kwh and no results. Does anyone else know anything about "actual" capacity being 78 Kwh?
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Model Y Battery 77-78 Kwh?
- Thread starter jmichaels
- Start date
Aside: it's kWh.
Unit symbols named after people are in upper case (even the omega for Ohm).
Unit symbols named after people are in upper case (even the omega for Ohm).
There is no one answer. It's not a deterministic value. There's manufacturing variation plus it depends on degradation, of course, but also usage conditions. A battery that is storing "75 kWh" of energy will deliver different amounts based on it's temperature and discharge rate.
The EPA test data is the most reliable battery capacity estimates I've seen for Tesla. This data is based on the amount of energy the battery can deliver from full to near shutdown, independent of a "0% or 0 mi range" indication to the driver. Tesla includes about 4.5% (or ~3.4 kWh) buffer at the bottom of the battery below 0% indicated SOC. This is included in the usable battery capacity estimate, but should not be relied upon while driving. It's there to ensure, due to all the challenges associated with estimating remaining battery energy, that the car doesn't need to shutdown above 0%, which would lead to very disappointed drivers.
Below are all the published Model 3 and Y Long Range battery capacity estimates from the EPA testing. All of these batteries were evaluated using the same measurement technique (SAE J1634) and even I think the same dynamometer at their Kato St facility. The J1634 standard requires cars be aged to at least 4,000 mi, therefore these batteries have already experienced a portion of the initial degradation process common to all Li-ion batteries.
It's clear there is variation that is likely attributable to cell manufacturing tolerances, or potentially how the cars were "aged" prior to the test. The average of these 8 samples is 78.6 kWh. Subtracting the lower 3.4 kWh buffer would yield an average 75.2 kWh available from 100% to 0% indicated SOC, but the range for these samples is 73.1 to 76.4 kWh.
I'll also mention that, to date, there are have been two iterations of the 2170 battery cell used in the Model 3. I don't know what the changes include, nor whether they affect capacity. I suspect the 2nd iteration was in use before the 2020 model year cars started being manufactured and all Model Y vehicles have the 2nd iteration, but have no evidence.
Links to the EPA Applications from which this data was gathered:
https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=48305&flag=1
https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=46585&flag=1
https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=48712&flag=1
https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=49398&flag=1
The EPA test data is the most reliable battery capacity estimates I've seen for Tesla. This data is based on the amount of energy the battery can deliver from full to near shutdown, independent of a "0% or 0 mi range" indication to the driver. Tesla includes about 4.5% (or ~3.4 kWh) buffer at the bottom of the battery below 0% indicated SOC. This is included in the usable battery capacity estimate, but should not be relied upon while driving. It's there to ensure, due to all the challenges associated with estimating remaining battery energy, that the car doesn't need to shutdown above 0%, which would lead to very disappointed drivers.
Below are all the published Model 3 and Y Long Range battery capacity estimates from the EPA testing. All of these batteries were evaluated using the same measurement technique (SAE J1634) and even I think the same dynamometer at their Kato St facility. The J1634 standard requires cars be aged to at least 4,000 mi, therefore these batteries have already experienced a portion of the initial degradation process common to all Li-ion batteries.
It's clear there is variation that is likely attributable to cell manufacturing tolerances, or potentially how the cars were "aged" prior to the test. The average of these 8 samples is 78.6 kWh. Subtracting the lower 3.4 kWh buffer would yield an average 75.2 kWh available from 100% to 0% indicated SOC, but the range for these samples is 73.1 to 76.4 kWh.
I'll also mention that, to date, there are have been two iterations of the 2170 battery cell used in the Model 3. I don't know what the changes include, nor whether they affect capacity. I suspect the 2nd iteration was in use before the 2020 model year cars started being manufactured and all Model Y vehicles have the 2nd iteration, but have no evidence.
Links to the EPA Applications from which this data was gathered:
https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=48305&flag=1
https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=46585&flag=1
https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=48712&flag=1
https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=49398&flag=1
Last edited:
Zoomit, this is EXCELLENT stuff. Thank you a bunch for the info. Very helpful. I think I am going with the 78 kWh (got the capital right this time, LOL) as ABSOLUTE MAX capacity (in a perfect situation), 74-75 as "real capacity" and 72-73 to "max useable capital without high anxiety". All before any age based degradation. Make sense?
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