Germany’s ADAC, the country’s largest automobile association, has released test results showing a Tesla Model Y experienced a 14% loss in battery capacity and a 22% drop in peak charging power after accumulating 140,000 kilometers (87,000 miles). The vehicle, a 2022 model used extensively for long-distance travel, also saw its fast-charging efficiency decline by 13% during 30-minute charging sessions, according to the association’s findings published on July 13.
Battery Degradation and Charging Performance
The Model Y, part of ADAC’s fleet, was first evaluated at 100,000 kilometers (62,000 miles), where it retained 91-92% of its original battery capacity. By 140,000 kilometers, that figure had fallen to 86%, reflecting a 14% reduction in usable battery capacity. While such degradation aligns with expectations for high-mileage electric vehicles, ADAC’s data also revealed a less frequently documented issue: a significant decline in peak charging power.
When new, the Model Y achieved a maximum charging rate of 257 kW at Tesla Superchargers. After 140,000 kilometers, its peak charging power had dropped to just over 200 kW—a 22% decrease. This reduction directly impacted the vehicle’s ability to recharge quickly. In controlled tests, the Model Y added 48.4 kWh in 30 minutes at a fast charger, down from 55.7 kWh when new, translating to a 13% decline in charging efficiency. The range added during a 30-minute session fell from 295 kilometers to 256 kilometers.
Usage Patterns and Comparative Analysis
The Model Y was primarily used for long highway trips and relied heavily on fast charging, though ADAC did not disclose specific details about its charging history or typical state-of-charge ranges. Despite the degradation, the vehicle maintained an average efficiency of 21.2 kWh per 100 kilometers (equivalent to 2.93 miles per kWh), allowing it to achieve a real-world range of up to 400 kilometers (250 miles) on a single charge. ADAC described the Model Y as reliable and dependable, continuing to favor it for long-distance travel due to its efficiency and range.
In a separate evaluation, ADAC tested a Volkswagen ID.3 with 220,000 kilometers (136,000 miles), which retained 89% of its battery capacity—outperforming the Model Y in battery health retention. Both vehicles use nickel-rich lithium-ion batteries, though ADAC did not specify whether the Model Y’s battery chemistry was NMC (nickel-manganese-cobalt) or NCA (nickel-cobalt-aluminum). The ID.3’s superior performance suggests potential differences in battery management systems or usage patterns, though ADAC did not provide additional details on charging habits or environmental conditions for either vehicle.
Broader Implications for Electric Vehicle Owners
ADAC’s findings underscore a critical but often overlooked aspect of battery aging: the decline in charging speed. While battery capacity loss is a well-documented concern, the reduction in peak charging power can have a more immediate impact on the practicality of electric vehicles, particularly for drivers who rely on fast charging for long-distance travel. The 13% decrease in energy added during a 30-minute charging session represents a tangible inconvenience, extending downtime during trips.
The test also raises important questions about the long-term performance of electric vehicles. The Model Y’s degradation, while not severe, highlights the need for more transparent data on how factors such as battery chemistry, charging frequency, and environmental conditions influence longevity. Without a complete charging history or maintenance records, it remains unclear whether the observed changes are typical for the Model Y or an outlier. ADAC’s ongoing fleet testing may provide further clarity as additional high-mileage electric vehicles undergo evaluation.
For current and prospective electric vehicle owners, the results serve as a reminder that battery health encompasses more than just range. Charging performance is a key consideration, particularly for vehicles subjected to frequent fast charging. As electric vehicles accumulate higher mileage, understanding how battery degradation affects both range and charging speed will be essential for making informed ownership decisions.
