Why Can't New Energy Vehicles Charge to 100%?
4 Answers
New energy vehicles often fail to charge up to 100%, and the fundamental reason for this phenomenon lies in the current limitations of battery technology. For safety considerations, the charging current decreases when the battery reaches a certain level of charge. At a specific charging point (e.g., 99%), the current drops to just a few tenths of an ampere. There are two primary charging methods for new energy vehicles: 1. Public Charging Stations: As of August 2019, with the increasing number of brands and quantities of new energy vehicles, a significant number of public charging stations have been installed. When using public charging stations, it's important to distinguish between fast charging and slow charging. Generally, fast charging at public stations is sufficient, allowing the vehicle to be fully charged within 1 to 2 hours without disrupting normal driving. 2. Home Charging Equipment: Charging with home equipment is safer and more cost-effective. However, the charging speed is slower, typically requiring 8 to 10 hours for a full charge.
I bought an electric car some time ago and noticed that charging always stops at 90%. This is actually to protect the battery lifespan. The battery management system automatically controls the charging level. If charged to 100%, lithium-ion batteries tend to age faster and degrade more quickly, just like how smartphone batteries lose capacity over time. Manufacturers do this to avoid safety issues caused by overcharging, such as overheating or explosion risks. I consulted and learned that it's sufficient to charge to 80-90% in daily use, which can also save on electricity costs. Regular maintenance is equally important, including checking the charger and software updates, so driving feels more reassuring without constantly worrying about expensive battery replacements. Remember, this is for the car's long-term durability, not a design flaw.
As a car owner, I used to think the charging equipment was faulty when it consistently stopped around 85%. Later, a technician explained this was by design: during fast charging, the system protects the battery by avoiding full-capacity charging to reduce battery fatigue and potential damage. This strategy is widely adopted by EV manufacturers to extend battery life by several years while lowering maintenance costs. From experience, I've learned that slow charging at home offers more stable performance while being cost-effective. For daily use, whether the battery is fully charged or not doesn't affect driving – it's better to monitor the battery gauge and plan trips accordingly.
The main reason for not charging to 100% is safety concerns. When the battery is fully charged, maintaining it at full capacity for extended periods increases internal pressure, posing risks of leakage or fire. Manufacturers implement software limits on charging levels to prevent these hazards, especially in high ambient temperatures. I recommend following the owner's manual and keeping the charge between 80-90%, which ensures safe driving and benefits battery health. Regular maintenance can also help reduce unexpected issues.
