GoKawiilAn absolutely valid question at this point is why EV batteries are lasting longer than lab tests predicted. There are quite a few reasons, starting with advances in battery tech and continuing with the differences between lab testing and actual real-world driving.
When it comes to batteries, the tech behind them has improved over the years. Viet Nguyen-Tien, a research officer who focuses on EVs at the London School of Economics, told the Wall Street Journal that three core improvements have contributed to the current success of modern batteries. First of all, they have a better chemical composition than those found in the first few generations of EVs. Second of all, they have smarter management systems and, lastly, more effective thermal regulation.
As a side effect, battery prices have also fallen more than 90 percent since 2010 according to a BloombergNEF report. Manufacturers also build packs designed for repairability, so individual cells can often be replaced rather than the entire unit.
Another important reason why EV batteries last longer than lab tests predicted is because lab tests can't really simulate real-world driving behavior. In a lab setting, batteries are typically subjected to continuous constant-current discharging where they essentially drain them at a steady, relentless pace from full to empty. Real-world driving however, is highly dynamic.
Stanford University's SLAC-Stanford Battery Center tested 92 commercial lithium-ion EV batteries across different discharge profiles over two years. The tests sought to mimic actual real-world driving, including stop-and-go traffic, short acceleration bursts, regenerative braking and long rest periods. Under these circumstances, battery life is extended by up to 38 percent compared to the constant-current discharge used in standard lab tests.