About Battery Health
Tessie’s Battery Health features help you track your vehicle's battery performance over time.
How to view battery health
Visit Battery Health or tap Battery and the heart icon in the app.
How range health is measured
Tessie compares your current range to the original range when new.
Example: 300 miles range now ÷ 400 miles range when new = 75% health (25% degradation)
Your vehicle’s Battery Management System (BMS) estimates battery range and capacity. Tessie records these fluctuating measurements after each charge of more than 5 kWh.
How charge cycles are measured
Tessie counts the number of times the battery is fully charged.
Example: Charging 80–90% ten times = one cycle
Past cycles from before you activated Tessie are estimated from your vehicle’s real-world energy usage and will become more accurate as more data is collected.
Compared to Tesla's battery health test
Tesla's Battery Health test
- Runs manually when triggered
- Completely drains the battery to 0% then recharges it to 100%
- Takes around 24 hours and renders the vehicle unusable
- Produces a single score based on range & age
- Produces a lower score than Tessie because it reduces your score based on age
Tessie's Battery Health monitoring
- Runs continuously in the background
- Does not require battery drain or charging to full
- Produces a continuously updated score based on range
- Produces graphs for max range, capacity, charge cycles and lifetime energy usage
How the original capacity is determined
Tessie uses the average new capacity for vehicles like yours, then updates it as more data becomes available from other users.
You can also set the original capacity yourself by selecting the number on the health gauge.
What degradation is normal?
Batteries start losing capacity right away and often stabilize around a 10% loss. The rate depends on the specific battery type in your vehicle.
How can I minimize degradation?
See Minimizing Battery Degradation for tips.
Why did I see a sudden change?
This can happen after a configuration change (like wheel size) or a Tesla firmware update. When this happens, it’s a good idea to recalibrate the BMS.
If the battery is replaced
Use the Set Battery Date button and enter the installation date of the new battery. Tessie will recalculate health using data from the replacement.
If calculations look unusually high or low
The BMS may need calibration. Recalibrating can improve accuracy.