Yes, using the headlights can drain the battery, especially if you forget to turn it off overnight. When the car stalls, the generator will stop working. At that time, the only power source for the entire car comes from the battery. If the headlights are on for a long time, it is easy to cause insufficient battery power, thus affecting engine start, shortening battery life. So, don’t forget to turn the headlights off when they are not used.