BYD's incredibly rapid Flash charging technology for electric vehicles became so hot that it could roast a turkey.

      A real-world evaluation of BYD's Megawatt Flash Charge technology revealed that the battery temperature reached 169.6°F during the charging process. This temperature is sufficiently high enough to cook a turkey and significantly surpasses China's recommended safety threshold of 149°F for lithium iron phosphate battery cells. Conducted by an automotive blogger who livestreamed the event (via ChinaEVHome), the test has raised concerns regarding the potential long-term effects of ultra-fast charging on battery health due to the excessive heat generated.

      The significance of the heat

      Typically, EV battery cells operate within a temperature range of 68°F to 86°F under standard driving and charging conditions, with most vehicles issuing overheating alerts when temperatures exceed 140°F. The temperatures recorded in this test place significant stress on the Solid Electrolyte Interphase (SEI) layer, which serves as a protective barrier separating the electrolyte from the anode while permitting lithium ion flow.

      Experts in battery technology indicate that this SEI layer begins to break down above 158°F. This raises concerns about the possibility of accelerated battery deterioration from repeated exposure to such high temperatures.

      BYD reportedly expected this level of scrutiny. When they introduced the second-generation Blade Battery, company executives highlighted a lifetime warranty on the battery cells and stated that the new battery pack improves capacity retention by 2.5% compared to the prior generation. Additionally, BYD showcased the battery's durability by intentionally short-circuiting four cells and maintaining that condition for 24 hours, with no fires or explosions reported.

      The larger context

      BYD is not the only company venturing into fast charging technologies. Although its advancements surpass those of many automakers, including Tesla, Porsche, Hyundai, and Lucid, Chinese rivals like CATL and Geely have created battery platforms capable of charging rates that go beyond BYD’s current megawatt charging capacities.

      As the industry strives for increasingly rapid charging solutions, effectively managing heat without compromising battery longevity is becoming as crucial as the speed itself. CATL has claimed to have solved this challenge with its 5C lithium-ion battery; however, this technology has yet to be introduced to the market.