Why does my battery keep dying with a new alternator?

Some of the most common reasons for a car battery to die repeatedly include loose or corroded battery connections, persistent electrical drains, charging problems, constantly demanding more power than the alternator can provide, and even extreme weather.

Can a new alternator drain a battery?

An alternator that’s not providing enough power can allow a battery to run down. According to Prestolite electric, an alternator producing less than 13.8 volts of power at idle is not producing enough current to charge the battery fully and needs to be replaced.

How do you check alternator by disconnecting battery?

If you’re tempted to test an alternator by disconnecting the negative battery cable, don’t do it. A good alternator may indeed keep the engine running without the negative cable, but this was never a good test. In the pre-computer days, you could pull it off without damaging anything.

How long does it take for a bad alternator to drain a new 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.

Why is my new car battery draining so fast?

There may be a problem in the starting system. 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.

How do I know if my alternator has a bad diode?

Usually, a bad alternator diode will cause your headlights or instrument panel lights to flicker or dim and, sometimes, drain battery power overnight, or in minutes. * To check for a possible bad alternator diode, switch your voltmeter to a low setting on the AC (alternating current) voltage scale.

Why does my car battery keep draining while driving?

Defective alternator: The mission of the alternator is to charge the battery while the car is running. If your alternator has a bad diode, it will cause your battery to drain. Old battery: I usually change my car battery every 3 years. Some people do it every 4-5 years, but your car battery might be good to go even after 7 years.

Can a bad alternator drain a car battery?

Defective alternator: The mission of the alternator is to charge the battery while the car is running. If your alternator has a bad diode, it will cause your battery to drain. Old battery: I usually change my car battery every 3 years.

What does it mean when your alternator is holding a charge?

If your alternator is working and your battery is holding a charge – it means something is killing your battery when your alternator isn’t charging it! That means you have a draw. Make sure your alternator’s wiring is right to go. It’s rare, but it does happen.

What causes a car battery to stop charging after a while?

Or a diode can leak, allowing current to flow after the vehicle engine is shut off. A worn or loose drive belt, or a weak belt tensioner, will also interfere with charging. Parasitic drains are also capable of killing a battery.