BYD Battery CTO Addresses "Flash Charging Damages Batteries" Concerns: Technology Continues Pushing Physical Limits

In an interview, Sun Huajun, CTO of BYD’s Battery Business Group, addressed concerns about whether "ultra-fast charging damages batteries." He acknowledged that high-current charging indeed generates higher temperatures and that traditional thermal management technologies can no longer keep pace with the heat generation rate of ultra-fast charging—a physical reality. However, he emphasized that it would be overly simplistic to assume ultra-fast charging inherently harms batteries. Historically, every generational leap in charging speed—from 1C to 2C, 4C, and even 5C—initially faced similar skepticism, yet technological advancements have consistently overcome these challenges. Sun noted that the industry’s understanding of the upper temperature limits for battery operation continues to evolve. For instance, while lithium iron phosphate (LFP) batteries were once considered to have a maximum operating temperature of 60°C, 70°C is no longer viewed as an absolute boundary. He argued against evaluating new technologies through outdated assumptions or conventional thinking, advocating instead for continuous innovation to push beyond physical limitations. Responding to comments from executives at rival companies claiming that “using LFP batteries in vehicles priced above RMB 250,000 amounts to de facto downgrading,” Sun stated that battery suppliers should not define what constitutes a premium vehicle. In his view, “premium” status should be determined by consumers based on holistic experiences—including chassis dynamics, ride comfort, charging speed, and long-term safety—not solely on energy density. Defining premium vehicles based on a single battery metric, he added, disregards automakers’ engineering capabilities and overlooks real user preferences. While acknowledging inherent technical limitations of LFP chemistry, Sun expressed confidence that there remains significant room for improvement. BYD believes it can further increase the system-level energy density of its LFP battery platform within the next few years. According to official BYD data, vehicles equipped with the second-generation Blade Battery can charge from 10% to 70% in just five minutes and reach 97% in nine minutes. Even in extreme cold conditions of -30°C, charging from 20% to 97% takes approximately 12 minutes—only three minutes longer than under normal temperatures. The company also confirmed that this ultra-fast charging technology does not compromise battery lifespan and actually improves overall capacity retention under warranty by 2.5%.