Tesla battery state-of-health audit
Select your model and trim below, then enter your odometer reading and current displayed range. Calculations run locally in your browser with zero sign-up or tracking.
"Log your rated range once a month. Carvico calculates your degradation slope and alerts you if your pack begins degrading faster than the fleet median."
"Carvico plots your monthly check-ins against your factory warranty cutoff date to predict whether you qualify for an in-warranty pack replacement."
"Is your missing range temporary cold penalty or permanent chemical decay? Carvico automatically normalizes your range logs by seasonal ambient temperature."
📲 Save Your Baseline to Carvico
Scan to open in the Carvico iOS app. Track your Tesla battery health over time with zero cloud accounts or API credentials.
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Track degradation slope over time — calculate velocity and identify cell brick imbalance early
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Log Home vs Supercharging $/kWh costs — native EV charging log with price/kWh and true efficiency
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Predict 70% warranty breach date — plot monthly check-ins against cutoff date for pack replacements
Scan with iPhone Camera
At 42,000 miles, this battery has completed its initial front-loaded SEI layer passivation (3–5% loss) and is degrading at a normal calendar aging rate of ~1.1% per year. Recharging retention is consistent with the 20,000+ vehicle fleet median.
Fleet Benchmark Analysis
Degradation curve vs. fleet benchmark
Tesla battery degradation is heavily front-loaded: lithium packs typically lose 3% to 5% during the first 15,000 miles as the Solid Electrolyte Interphase (SEI) passivation layer stabilizes on cell anodes. Degradation then flattens to a predictable 1.0% to 1.3% per year. Here is where this vehicle stands against the wider fleet:
| Milestone | Typical Fleet Retention | Top 10% (Healthy) | Bottom 10% (High Loss) | Projected Range (This Car) |
|---|
Want millivolt cell-level precision? Unlock raw BMS diagnostics
The Tesla dashboard displays an approximated software range calculated by the vehicle computer. To inspect the actual physical condition of your battery pack, technicians connect directly to the internal CAN-bus diagnostic port.
Tesla CAN Diagnostic Cable
Direct plug-and-play adapter harness connecting to the internal vehicle diagnostic port behind the center console or under the dash. Zero wire splicing, completely reversible and warranty safe.
Carvico Tesla Diagnostic Scanner Bundle
OBDLink Bluetooth Low Energy scanner paired with the model-specific Tesla CAN harness. Read nominal full pack kWh, brick voltage imbalance (mV), buffer capacity, and lifetime Supercharger kWh.
- Nominal Full Pack (kWh): The exact usable battery capacity stored in BMS non-volatile memory.
- Cell Brick Voltage Delta (mV): Measures voltage difference between individual cell modules. Less than 8 mV is pristine; over 30 mV indicates a degraded cell block.
- Lifetime AC vs. DC Fast Charging Ratio: The exact total energy ingested from Level 2 home chargers vs. high-power Superchargers.
- Energy Buffer Capacity (kWh): The hidden reserve capacity below 0% displayed state-of-charge (typically 4.5 kWh).
LFP vs. NMC: Why chemistry dictates your charging routine
Tesla equips vehicles with two distinct battery chemistries. Your chemistry determines whether charging to 100% preserves or degrades your pack:
| Specification | LFP (Lithium Iron Phosphate) | NMC / NCA (Nickel-Cobalt) |
|---|---|---|
| Equipped Models | Model 3 RWD (2022+), Model Y RWD (2023+), Standard Range Highland | All Long Range, Performance, Model S, Model X, Cybertruck |
| Daily Charging Limit | 100% recommended (minimum once weekly) | 80% recommended for daily driving |
| Degradation Mechanism | Extremely slow chemical wear; 3,000–4,000 cycle lifespan | Cathode lattice strain and oxidation at high sustained voltage (>4.15V/cell) |
| BMS Calibration Behavior | Voltage curve is extremely flat between 20% and 80%. Requires 100% charge to calibrate state-of-charge. | Sloping voltage curve allows accurate BMS estimation without 100% charges. |
| Thermal Runaway Safety | Chemically stable up to 500°F (260°C); near-zero runaway risk | High energy density; relies on active liquid glycol thermal conditioning |
Tesla battery warranty & the 70% retention rule
Every Tesla sold in the United States is backed by an 8-year federal traction battery warranty guaranteeing a minimum of 70% capacity retention. If your battery degrades past 30% loss (falling below 70% state of health) within the coverage period, Tesla is legally required to repair or replace the pack free of charge.
Warranty coverage thresholds by model:
- Model 3 & Model Y Rear-Wheel Drive: 8 years or 100,000 miles (160,000 km), whichever comes first, with minimum 70% retention.
- Model 3 & Model Y Long Range / Performance / AWD: 8 years or 120,000 miles (192,000 km), whichever comes first, with minimum 70% retention.
- Model S & Model X: 8 years or 150,000 miles (240,000 km), whichever comes first, with minimum 70% retention.
- Cybertruck: 8 years or 150,000 miles (240,000 km), with minimum 70% retention.
Frequently asked questions
How do I check my Tesla battery degradation without Service Mode?
Charge your car to 100% and divide the displayed mileage by the vehicle's original EPA rated range when new. For example, if a 2021 Model 3 Long Range (originally rated at 358 miles) displays 333 miles at 100%, its retained state of health is 333 / 358 = 93.0% (7.0% degradation). Alternatively, divide your range at 80% by 0.80 to calculate the 100% equivalent.
How much does a Tesla battery replacement cost out of warranty?
An out-of-pocket traction battery replacement for a Tesla Model 3 or Model Y typically costs between $12,000 and $16,500 (including remanufactured pack cell balance and shop labor). For Model S and Model X with larger 100 kWh packs, replacement costs range from $15,000 to $20,000. However, sudden pack failures are exceptionally rare; the vast majority of packs degrade smoothly over 150,000+ miles.
Is 10% battery degradation normal on a 3-year-old Tesla?
Yes. Battery degradation in modern lithium-ion packs is front-loaded. A typical Tesla loses 5% to 8% in the first two years (25,000 to 40,000 miles) as the solid electrolyte interphase (SEI) stabilizes on the anodes. After year two, degradation drops to a steady 1.0% to 1.2% per year. Reaching 10% degradation around 50,000 to 60,000 miles is completely normal and on par with fleet averages.
Can Tesla replace my battery under warranty for range loss?
Only if the battery drops below 70% of its original capacity within the 8-year warranty window (100,000 to 120,000 miles depending on trim). Dropping below 70% requires losing over 100 miles of rated range on a Long Range vehicle, which occurs in less than 1.5% of vehicles, usually due to a defective cell brick rather than normal chemical aging.
How do I fix Tesla BMS calculation drift?
If you routinely charge in a narrow band (e.g. 50% to 70%), the vehicle's computer (BMS) cannot accurately read the cell resting open-circuit voltage. For NMC cars, drive the battery down to 10%–15%, let it sleep for 3 hours, then charge to 95%–100% and drive immediately. For LFP cars, simply charge to 100% on Level 2 and let it sleep plugged in for 2 hours to balance the cells.