Tesla Model 3 Battery Health After 150,000 Miles: Long-Term EV Battery Performance

Electric vehicle batteries inevitably lose some capacity over time and use. But how much degradation can EV owners expect after years on the road? To answer this question, we're taking a close look at battery health in a 2019 Tesla Model 3 that has racked up 150,000 miles.

Background on the Test Vehicle

This particular Model 3 has been part of the Out of Spec Reviews fleet since new. It's equipped with the original 74 kWh Panasonic NMC (nickel-manganese-cobalt) battery pack. The car has seen extensive use over the past 4+ years:

• Driven in all 48 contiguous US states and Canada
• Frequent road trips and Supercharging sessions
• Track use and high-speed runs
• Often discharged to very low states of charge

Despite this heavy use profile, the car has been well-maintained. When not in use, it's typically stored at a 50% state of charge in a climate-controlled environment. This helps minimize calendar aging of the battery cells.

Running the Battery Health Test

Tesla recently updated their battery health monitoring system, allowing owners to run an automated test to check capacity. Here's how the process works:

1. Drive the car down to a low state of charge (3% in this case)
2. Connect to an AC charging station
3. Navigate to Controls > Service > Battery Health in the car's menu
4. Initiate the test, which takes up to 15 hours
5. The car will discharge and recharge the pack to measure capacity

Once complete, the test provides a battery health percentage score. This represents the pack's current capacity compared to when new.

Battery Health Results

After running the official Tesla battery health test, this Model 3 scored 81% capacity remaining after 150,000 miles.

Some key takeaways:

• The pack has lost approximately 19% capacity since new
• This aligns with the reduced range observed (now ~250 miles vs. 310 when new)
• The degradation is noticeable but not catastrophic for a high-mileage EV
• Many newer Teslas with lower mileage show worse scores

While 19% capacity loss is significant, it's important to note this car has been used very hard over its lifetime. The fact that it retains 81% capacity after such extensive use speaks to the durability of Tesla's early Model 3 battery packs.

Factors Affecting Battery Degradation

Several factors influence how quickly an EV battery pack loses capacity:

Chemistry

Different lithium-ion chemistries have varying degradation profiles:

• NMC/NCA: Higher energy density but can degrade faster
• LFP: More stable long-term but lower energy density
• This Model 3 uses an NMC pack, which typically sees more degradation than newer LFP packs

Temperature

Extreme heat accelerates battery aging. Storing or charging EVs in very hot conditions can cause faster capacity loss.

State of Charge

Keeping batteries at very high (100%) or very low states of charge for extended periods accelerates aging. A mid-range SoC (30-50%) is ideal for storage.

Charging Speed

Frequent DC fast charging may contribute to faster degradation, though the impact seems minimal with modern battery packs.

Usage Patterns

High-mileage EVs typically see more degradation, but calendar aging also plays a major role.

Best Practices for Battery Longevity

Based on the experience with this high-mileage Tesla, here are some tips for maximizing EV battery life:

1. Avoid storing the car at 100% charge, especially in hot weather
2. For long-term storage, keep the battery at 30-50% charge
3. Use the full range of the battery - don't be afraid to charge to 100% for trips
4. Minimize time spent at 100% charge - plug in just before you need max range
5. Don't stress about fast charging - modern EVs can handle it well
6. Consider climate when parking for extended periods

Measuring Battery Health

Accurately measuring EV battery health and capacity is challenging:

• Estimated range at 100% charge is not a reliable indicator
• Charging data is inaccurate due to losses in the system
• The most accurate method is a full discharge test, measuring energy used

Tesla's new built-in battery health test appears to correlate well with full discharge tests. This gives owners a convenient way to check battery status.

Implications for the Used EV Market

Battery health is a major concern for used EV buyers. However, predicting future battery performance is difficult:

• A healthy battery today doesn't guarantee future performance
• Sudden failures can occur even with gradual degradation curves
• Standardized battery health reporting is still evolving

As the EV market matures, expect to see more robust battery health metrics and perhaps even certifications for used vehicles.

Conclusion

After 150,000 miles of hard use, this Tesla Model 3 retains 81% of its original battery capacity. While the range loss is noticeable, it hasn't significantly impacted the car's usability. This real-world data point should give confidence to EV owners and potential buyers about the long-term viability of electric vehicle batteries.

Modern EVs are proving more durable than many expected. With proper care and reasonable expectations around gradual capacity loss, today's electric cars can provide many years and hundreds of thousands of miles of service. As battery technology continues to advance, we can expect even better longevity from future EVs.

Continued research and standardization around battery health measurement will be crucial as the used EV market grows. For now, this high-mileage Tesla serves as a positive example of how well electric vehicle batteries can hold up over time and heavy use.

Article created from: https://youtu.be/dWPc_JutxKU?feature=shared