At What Remaining Battery Level Should an Electric Vehicle Be Charged?
2 Answers
It is appropriate to charge an electric vehicle when the battery level remains at 40%, as the battery is in the plateau region, which is beneficial for battery lifespan. A scientifically correct charging method is an important factor in ensuring battery condition and usage cycle. When the battery level drops to 20%, there may be inaccuracies in battery level estimation, and the battery might no longer be in the plateau region. Charging at this point can shorten the battery's lifespan, and the vehicle may also experience sudden breakdowns or become undrivable. In practical usage, charging an electric vehicle should follow the principle of shallow charging and discharging, avoiding full discharge. Pure electric vehicles use ternary lithium batteries, which have minimal memory effect. Unlike other batteries, they do not have charging memory, meaning the battery's condition is not affected by the amount of charging. The power battery in electric vehicles is designed for cycle usage, and frequent charging does not negatively impact the power battery.
I usually charge when the battery drops to around 20%, which is best for battery health. Lithium batteries are actually similar to smartphone batteries - fully draining them each time harms the battery, and keeping them fully charged all the time isn't good either. Manufacturer manuals generally recommend charging when remaining capacity is between 20%-30% as ideal, as this avoids deep discharge damage while extending battery life. Especially during winter or summer when using air conditioning, I always keep an extra 10% charge as backup. Of course, I'll make an exception to fully charge when preparing for long trips, but for daily commuting there's really no need to charge to 100% every day. By the way, many vehicle systems now allow setting charging limits - I usually cap mine at 90%.
