Published on June 12th, 2018 | by Kyle Field0
Tesla Battery Charging Analysis Reveals Different Charging Rates For Each Battery Size
June 12th, 2018 by Kyle Field
A new analysis of Tesla battery charging behavior by vehicle and battery type offers new insights into Tesla’s Supercharging curves and how drastically the activity is for different vehicles and batteries.
A Better Route Planner collected data from 801 Tesla owners across 4,600 Supercharging sessions, capturing the state of charge over time throughout the charging session. These data were then tossed onto graphs, which revealed very different trends depending on battery type. The analysis broke the batteries out by type:
¤ BT37: The 75 kWh battery in a Model 3 Long Range
¤ BT60: The old S60 60 kWh battery
¤ BT70: The old S70 70 kWh battery
¤ BT85: The classic “85” kWh battery in a Model S85
¤ BTX4: The 90 kWh battery in S90 and X90
¤ BTX5: The 75 kWh battery in S75 and X75
¤ BTX6: The top-of-the-line battery 100 kWh in S100 and X100
¤ BTX7: A rare 85 kWh battery, where we have almost no data
¤ BTX8: An 85 kWh battery found in some rare S75 and X75
The usefulness of the data from each battery type varies based on the number of data points for each. For example, the analysis only had data from 13 Model 3 Long Range batteries, for a total of 38 data points. It’s neat to look at and the data does seem to confirm to a consistent trend, with high-power charging tapering off starting at 50% state of charge (SoC) down to about 95% SoC when the charging rate drops again.
One of the strange behavior trends identified by the analysis was with the battery in the S70, where the charge rate drops off much earlier than other vehicle/battery types, starting at a SoC of just 25%. That nets out to a slower overall charge.
In addition to the charging rate curves that follow the SoC of the battery, the analysis reveals insights into the useful battery capacity of each battery type. Most of the batteries included in the analysis show capacities just under the stated capacity. The Model 3 Long Range battery at 75kWh, for instance, was estimated to be 73.4 kWh, and the Model S and X 100 kWh battery was estimated to have a useful capacity of 95.7kWh.
The analysis revealed that there were also a few batteries that fell significantly short of their nameplate, with the Model S 85 being estimated to have a usable capacity of 73.4kWh, which is awkwardly the same as the 75kWh battery above. Hmm…
For a deeper dive into the trends, head over to A Better Route Planner, which performed the analysis.