How long can hazard lights last when the engine is off?
2 Answers
Hazard lights can last for a full day and night when the engine is off. The hazard warning flasher, commonly known as the hazard lights or emergency flashers, is a functional lighting system used to alert other vehicles in case of emergencies. It is also necessary to turn on the hazard lights when parking on the roadside to prevent rear-end collisions. Situations requiring the use of hazard lights include: 1. Driving in foggy conditions—due to poor visibility, both hazard lights and fog lights should be activated; 2. In case of vehicle breakdown or traffic accidents on the road, hazard lights should be turned on to alert passing vehicles for safety; 3. When towing a malfunctioning vehicle, both the towing vehicle and the towed vehicle should activate hazard lights to indicate their non-normal status; 4. When temporarily parked on the road, hazard lights should be used to warn other vehicles; 5. When forming a convoy permitted by traffic authorities, all vehicles in the convoy should turn on their hazard lights.
The duration of keeping hazard lights on with the engine off mainly depends on the battery condition. I've tried it a few times with my own small car, and it usually lasts about 5-10 hours, but don't expect much longer. Car batteries typically have capacities between 45 to 70Ah, and hazard lights only consume around 0.5 amps. Theoretically, this could last over a hundred hours, but in reality, it's not possible due to battery aging. Over time, batteries lose charge faster, especially when affected by temperature extremes or dry weather. If you leave them on too long and drain the battery completely, you'll face the hassle of a car that won't start, requiring a tow truck and costly repairs. A friend of mine recently had this happen and waited half an hour for roadside assistance. Remember to set an alarm to remind yourself to turn off the lights before leaving the car—safety first, plus it saves money and extends battery life. In winter, it might last a bit longer. In short, don't exceed a few hours, or the cost of battery repairs will be much higher.
