How long does it take to fully charge a car after a jump start?
2 Answers
A car can be fully charged in about two hours after a jump start. The method for jump-starting and charging is as follows: 1. Position the two cars facing each other, open the front hood, and take out the charging clamps; 2. Attach the positive clamps to the positive terminals of both car batteries; 3. Attach the negative clamps to the negative terminals of both car batteries; 4. Start the rescue vehicle. Other methods for dealing with a dead car battery include: 1. The push-start method: Engage first gear and slowly release the clutch to use the turning force of the wheels to rotate the engine flywheel; 2. The tow-start method: Use a tow rope of appropriate length to securely tie the stalled vehicle to the rescue vehicle.
Last time my car ran out of battery in the supermarket parking lot, luckily a friend helped jump-start it. After starting, I immediately drove home, which only took twenty minutes, but the next morning it wouldn't start again. The mechanic reminded me that after a jump-start, you need to drive for at least thirty to forty minutes to let the alternator charge the battery, but this only restores starting capability. A full charge depends on the situation: if the battery is new and not deeply discharged, driving for about an hour is usually enough; for an old battery or one completely dead, you might need to drive continuously for two to three hours or even longer. Also, driving on the highway charges faster than at low speeds because the engine runs at higher RPMs, producing more current. I later got a portable charger, and charging overnight at home definitely does the trick, avoiding roadside issues.
