Does the battery powers the vehicle or the alternator

2013 DODGE CARAVAN
59,350 MILES • 3.6L • 6 CYL • 2WD • AUTOMATIC
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KGETZ
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I know I had this conversation with a few on here regarding whether the battery powers the vehicle or the alternator. Just so I understand correctly, does the power go from the alternator to the battery, then from the battery to the electrical system? I just want to make sure I am understanding correctly. I had this conversation with my Dad as well.
Sep 27, 2018 at 12:42 AM
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HARRY P
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I would say that the battery powers the vehicle, and the alternator keeps the battery charged. If the alternator stops working, the car will still run until the battery is out of juice. If the battery quits, the alternator will keep the car running until you shut it off, and then it will not start without addressing the battery or getting a jump start.
Sep 27, 2018 at 3:38 AM
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ASEMASTER6371
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Good morning.

You are half right. The battery will keep the car running without the alternator working until the voltage goes below 12 volts.

The alternator will not keep the engine running when the battery is bad. The alternator needs at least 12 volts to activate the magnets inside to make the alternator work. When the battery goes dead, the voltage stops and the engine will only run until the magnets are out of voltage, then it will die. The alternator depends on battery voltage for it to work. No battery voltage, no alternator function.

Roy
Sep 27, 2018 at 4:07 AM
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KGETZ
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Does the alternator need constant draw off the battery to keep the magnets activated?
Sep 27, 2018 at 11:52 AM
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HARRY P
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Roy that is if the battery is totally completely shot. Usually a bad battery just will not hold charge, but is not a big enough draw to completely keep the alternator from doing its thing.
Sep 27, 2018 at 12:04 PM