A Tesla Model Y Battery Test Looked Bad. Then The Degradation Almost Stopped

A Tesla Model Y equipped with a lithium iron phosphate (LFP) battery pack exhibited significant degradation in its initial 10,000 miles, a period during which it was predominantly fast-charged. However, subsequent testing indicated that the battery's degradation rate has substantially slowed down after this initial phase. The vehicle, a 2023 Model Y Long Range, has accumulated approximately 25,000 miles, with about 70% of its charging cycles involving Tesla's Supercharger network. Data collected by the owner, who shared results on the Tesla Motors Club forum, revealed that the battery's State of Health (SoH) dropped from an initial 97% to around 87% within the first 10,000 miles. This early decline is consistent with expectations for LFP batteries, which can experience a steeper initial capacity loss. Following this period, the degradation curve appears to have flattened considerably, with the SoH remaining stable at approximately 86% to 87% over the subsequent 15,000 miles. The owner's charging habits, predominantly utilizing DC fast charging, were noted as a potential factor influencing this pattern. The findings suggest that while LFP batteries may show a more pronounced initial drop in capacity, their long-term stability could be robust, especially if charging patterns are managed.