What to Do When the Car Doesn't Shut Off After a Jump Start?

[LeSkylar]

Generally, this situation occurs because the car's starting current hasn't been fully charged, requiring additional jump-start time. Here's relevant information: 1. Typically, a jump start of 10 to 20 minutes is needed to charge the car battery sufficiently for starting, after which the battery can recharge itself while running. When a car battery is dead and can't provide starting current to the engine, connecting it to another vehicle's battery for a jump start is the solution. 2. A jump start, also known as a boost or jump, involves connecting another vehicle's battery or an external power source to a car with a depleted starting battery to start the vehicle. Once the vehicle starts, its normal charging system can recharge the battery, allowing the auxiliary power source to be removed. As long as the vehicle's charging system is functioning properly, a normally running vehicle will restore the battery's charge.

[VonEmery]

I've encountered situations where the car didn't dare to shut off after jump-starting, mainly because the battery wasn't sufficiently charged. Last time when I helped my neighbor jump-start his car, he revved the engine to around 2500 rpm for about 20 minutes, and only when the battery casing felt slightly warm did we consider some charge had gone in. At this point, you can turn off power-hungry devices like the AC, but maintain ventilation. If the battery warning light on the dashboard is still on, absolutely don't shut off the engine - you'll need to charge for another half hour. The safest approach is to drive for over half an hour, which both charges the battery and allows the alternator to work fully. If all else fails, head straight to an auto repair shop to test the battery's health - don't hesitate to replace it if needed.

[KevinLee]

If the engine doesn't stall after jump-starting, it means the battery is severely depleted! Here's how I usually handle it: First, turn on the headlights to check their brightness—if they're dim, don't turn off the engine. While keeping the engine running, quickly unplug all external devices like car chargers and dashcams. Listen for any unusual noises from the alternator and check if the belt is rotating normally. Remember to check the voltage display on the dashboard (some cars don't have this) and keep it above 13V for safety. Last time, I had to charge it for a full forty minutes before daring to turn off the engine. If the battery is over three years old, it's better to drive straight to get it tested and replaced for peace of mind.

[AdelineRose]

If you're afraid to turn off the engine after a jump start, don't panic. First, turn off all power-consuming devices like the AC and stereo, but leave the windows slightly open for ventilation. Then keep the engine running to charge the battery for at least 20 minutes. Meanwhile, observe the dashboard: Has the battery warning light gone off? Is the tachometer stable? Feel the side of the battery—if it's slightly warm, it means it's charging. For older cars, check the battery terminals for white corrosion. Pouring hot water over them can improve contact. After charging, it's recommended to drive directly to a repair shop to have the alternator and battery tested.

[DeOscar]

This situation is usually caused by a severely depleted battery or a faulty alternator. Last time I jump-started my car, I drove directly onto the highway for half an hour to ensure the most uniform charging while driving. During the charging process, pay special attention: do not lock the car doors (which may trigger the anti-theft system and consume power), and turn off the automatic headlight function. For cars with mechanical keys, keep the key in the ignition switch to prevent the computer from freezing. After charging, the test method is to turn off the engine and restart it immediately. If it starts successfully on the first try, there's generally no problem. If the battery has been in use for more than three years, it's recommended to replace it in advance to avoid further issues.

[JaceDella]

The situation where the car starts successfully but won't turn off often occurs in winter. My summarized experience is: first rev the engine to 2000 RPM for 10 minutes to charge, if the battery feels hot to the touch it's dangerous. During this period, pay attention to the engine sound - clicking noises may indicate alternator bearing damage. For newer vehicles, you can check the voltage display on the center console screen; below 13V is substandard. The safest approach is to charge for sufficient time, then drive to an auto repair shop for a battery tester reading - if the health value is below 350 CCA, the battery needs replacement. Remember to regularly clean battery terminal oxides to extend its lifespan.