How long does it take to fully charge a car battery when it's dead?

1 Answers
BriannaMarie
07/30/25 10:55am
When a car battery is dead, using the vehicle's alternator to fully charge it requires maintaining an engine speed of over 2000 RPM, and the car needs to be driven for at least 4 hours. If the engine speed cannot reach 2000 RPM, the charging time will be even longer. Car battery maintenance methods: Do not use in-car electrical equipment for extended periods when the engine is off; avoid repeatedly starting the vehicle; refrain from using external power devices when the engine is off; remember to turn off lights after parking; do not leave the car unused for long periods. Reasons for a dead car battery: Extended parking leading to battery discharge; battery reaching the end of its service life; insufficient battery electrolyte or leakage.
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