Can New Energy Vehicles Only Fast Charge Up to 80%?
3 Answers
New energy vehicles are not limited to fast charging up to 80%. Fast charging can rapidly charge the battery up to 80%, but it doesn't mean it can only charge to 80%. After reaching 80%, the charging speed slows down but continues to charge. Fast charging is a process that enables lithium ions to quickly deintercalate from the positive electrode and rapidly intercalate into the negative electrode. Hazards of Fast Charging: However, when the current increases, the semi-permeable membrane on the surface of the negative electrode may rupture to some extent, causing the electrode material and electrolyte to react with each other. Additionally, temperature rise may accompany some side reactions, such as electrolyte decomposition and deposition on the electrode, leading to reduced reversibility and a gradual decrease in battery capacity. Reason for Fast Charging Up to 80%: The most obvious manifestation is the accelerated battery degradation. Normally, it might take 1000 charge cycles to degrade to 80%, but with continuous fast charging, it might only take 500 cycles to reach the same level of degradation. This illustrates the significant damage long-term fast charging can cause to power batteries. To protect the power battery, manufacturers design the fast charging to only charge up to 80% of the battery capacity. The remaining charge must be completed through slow charging, which acts as a buffer and neutralization, thereby reducing the damage to the power battery.
As an automotive technology enthusiast, I understand that fast charging for new energy vehicles isn't limited to 80% by default. Instead, the intelligent system deliberately slows down to protect the battery. During lithium-ion battery charging, high-speed charging is possible at low charge levels (e.g., 0-80%). However, as the battery approaches full capacity, ion embedding slows down significantly. Fast charging at this stage dramatically increases heat accumulation risks, accelerating battery aging or capacity degradation. Therefore, the BMS (Battery Management System) automatically switches from fast charging to slow charging mode at around 80% to ensure long-term battery safety. Users can manually adjust the charging limit to 100% via the vehicle's app, especially during long trips requiring maximum range. However, frequent use of this feature should be avoided to prevent shortening battery lifespan. Setting an 80% charging limit for daily use is wise, extending battery life beyond 10 years while saving on future expensive repair costs.
I drive an electric vehicle daily. From a user experience perspective, fast charging can technically reach 100%, but in practice, it's often recommended to stop at 80%. The first 80% charges quickly, possibly in just tens of minutes, but the last 20% slows down to a trickle charge, taking an extra hour or two, which is too time-consuming. At charging stations, it's common to see people unplug and leave after reaching 80%, aiming to fit in more trips. My personal habit is to set the app's default charging limit to 80% to protect the battery from frequent overheating, only switching to 100% for long trips. Over time, this has kept my battery health above 90%, made charging stations more efficient, and saved both hassle and money.
