The battery warranty for BMW's 48V mild hybrid system usually aligns with the vehicle's overall warranty period. The current mainstream policy is 4 years or 80,000 kilometres (whichever comes first), and specific terms may vary slightly depending on the model and year of purchase. For example, the 2025 430i Convertible and M340 Sedan both offer a basic warranty of 48 months/50,000 miles (approximately 80,000 kilometres), covering powertrain components. Some brands provide longer-term protection for mild hybrid batteries; for instance, manufacturers like Volvo include 48V batteries in the new car limited warranty, but this is subject to the official manual. As an electrification transition solution for traditional fuel vehicles, the lithium batteries in 48V mild hybrid systems typically have a lifespan exceeding 10 years, though actual performance may vary depending on driving habits and climate conditions.
