Can a bad alternator cause battery drain?

A corroded or defective alternator diode will faultily continue charging the circuit even when the car off. This, in turn, will drain your car battery and cause the car not to start.

How long does it take a bad alternator to drain a battery?

In this situation, the battery could last as little as 30 minutes. If you are lucky and could get up to two hours. Note: In case you have to start the car without an alternator, don’t turn off the engine once you’re going. Starting the car flattens the battery down quickly.

What causes my car battery to drain so fast?

A short circuit may cause excessive current draw and drain your battery. Check the charging system for a loose or worn-out alternator belt, problems in the circuit (loose, disconnected or broken wires), or a failing alternator. Engine operation problems can also cause excessive battery drain during cranking.

What could be draining my car battery overnight?

This can be a result of various factors including the number one cause which is leaving headlights, glove box lights, or cabin lights on overnight. Parasitic drain can also be caused by defective fuses, bad wiring, and poor installation of a new car battery.

Can a bad battery ruin an alternator?

Don’t Ruin Your Alternator. Let’s say the car battery died, you replaced the alternator, then ran the engine to recharge the battery. Next thing you know the new alternator is bad. Vehicle alternators are not heavy duty enough to recharge dead batteries.

What are the signs of an alternator going bad?

The symptoms of a bad alternator include strange noises, similar to a grinding or whining noise and an illuminated warning light. Other less noticeable and less common symptoms include weird sounds and bad smells. A burning rubber smell becomes noticeable when the alternator is going bad because the alternator works with the belt system.

How do you know if your battery or alternator is bad?

If the battery is working, it’s time to take a closer look at the alternator. There are certain signs of a bad alternator to look for: While running the car, take note of the interior lights and how bright these appear. If the dashboard gradually dims, that likely means the alternator is at fault.

How do you recharge a dead car battery with a bad alternator?

Use jumper cables to recharge your dead battery using the live battery of a running car. Connect the jumper cables of the good battery and the bad battery, positive to positive and negative to negative. Run the engine of the well-charged car, by placing the car in parking mode, and gently stepping on the accelerator.