[?] Long-Term Capacity Degradation Under Flash Charging — Time Constraint

BYD’s claim that “flash charging has almost no effect on battery life” is a life degradation claim, not a safety claim. The 500-cycle safety test (no fire, no smoke after 500 flash-charge cycles) confirms safety behavior. It does not measure capacity retention — how much usable range remains after 500, 1,000, or 1,500 flash-charge cycles under real-world mixed-usage conditions.

This data does not exist because of a genuine time constraint, not commercial withholding. The Second-Generation Blade Battery entered mass production in March 2026. At typical fleet usage of 60,000 km per year and approximately 500 km per flash-charge session, 500 cycles represents approximately 250,000 km or approximately 4 years of operation. No production vehicle has completed this usage profile. Real-world long-cycle degradation data will not be available at meaningful scale until 2027 or 2028.

The only available reference data is indirect: the warranty threshold increase from 75% to 77.5% at 6 years / 150,000 km. This is a rational commercial signal — if BYD’s internal degradation modeling showed that flash charging significantly accelerated capacity loss, they would not have increased the warranty threshold simultaneously with introducing flash charging as the primary use case. But it is not proof. It is a signal.

For practitioners, the correct treatment of this gap in a TCO model: use 77.5% at 6 years / 150,000 km as the only available contractual planning boundary. Add a conservative battery replacement cost provision for Year 7 onwards — 20% of vehicle value is a reasonable placeholder pending actual data. Revisit when first independent long-cycle studies appear in peer-reviewed literature (expected 2027-2028).