Can a sedan charge while idling in place?
2 Answers
A sedan can charge while idling in place. Idling refers to a condition where the engine is running but the transmission is in neutral, meaning the vehicle is consuming fuel without moving. The charging duration can be affected by various factors, such as whether high-power devices are being used inside the car, whether the air conditioning is on, or if external USB power is being supplied—all of which can increase charging time. While charging is possible during idling, it is relatively fuel-consuming, and the emissions during idling are highly polluting. Occupants should not sleep in a sealed (recirculating air) car with the air conditioning on, as incomplete combustion in the engine can produce carbon monoxide (a colorless, odorless gas), which can accumulate to lethal levels inside the vehicle. If possible, it is recommended to use a battery charger to charge the car's battery instead.
Idling a car does recharge the battery since the running engine drives the alternator to replenish power. However, it's highly inefficient—the idle speed is low (around 800 RPM), resulting in minimal electricity generation and snail-paced charging. If the battery is already sufficiently charged, idling may show little effect. But if the battery is drained (e.g., from leaving headlights on), idling for half an hour might barely recover some charge. Don’t expect fast charging—normal driving at higher RPMs charges much faster, while idling just wastes fuel and money. I’ve experienced this with an old car: the aged battery struggled to start, and idling for 15 minutes barely provided enough juice to ignite. Practically, this method is only for emergencies. It’s better to adopt good habits, like avoiding deep discharges or checking battery health regularly. Relying on idling long-term increases emissions and environmental harm—hardly worth it. Short-term use is fine; just don’t abuse it.
