Q: Engine losses power when lights are on

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During night time my car turns on, but the engine loses power when I try to accelerate on drive. I have to ramain still until I have enough power to move. I changed spark plugs and battery, but problem persists

My car has 45000 miles.
My car's transmission is unknown to me.

Hello, thank you for writing in. There are a few different angles that we can look at this problem from. The first thing to discuss is that the battery performs very little once the vehicle is running. The battery is mostly utilized for starting the car, and completing the charging circuit. While it is false to say the battery serves no purpose, you should be more focused on the alternator not being able to supply the electrical energy the vehicle needs. This may be due to something robbing electricity from the vehicle or the alternator not working correctly. The alternator can be tested, and the draw from the charging circuit can be measured to see if there is excess resistance coming from somewhere. The later is a two part process that requires a ohmmeter. The alternator can be tested by a technician or at most local automotive parts stores. You may want to start there for complexities sake.

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