How long does it take to jump start a completely dead battery?

+1 vote
asked Feb 8, 2019 in Repairs/Maintenance by ermawz4 (370 points)
How long does it take to jump start a completely dead battery?

1 Answer

0 votes
answered Feb 8, 2019 by Essmann (42,860 points)
If the battery is completely dead on the car then when you're jump starting the car let the car that's jump starting the dead car battery run for around 5 minutes at idle and rev the engine up a little for a 30 seconds or a minute at a time to allow the alternator on the jump starting car charge the dead battery.

Then after 5 minutes try to start the car with the dead battery and if it still doesn't then allow another 5 minutes of the car idling then try starting the car with the dead battery again.

If the battery is good then the car should be able to start after 10 minutes and if not then the dead battery probably has a dead cell and cannot be charged.

If that's the problem then you'll need a new battery.

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