How Long Does It Take For A Bad Alternator To Drain A Battery?

If you’ve detected the term “alternator” before, you almost certainly grasp that it’s an important part of your vehicle. However, what specifically will an alternator do? Your alternator keeps your car battery charged, permitting you to show on your automobile and use electronic accessories like your headlights and radio. But How Long Does It Take For A Bad Alternator To Drain A Battery?

If you’re experiencing automobile alternator issues, you will realize that your automobile won’t begin or be for quite many minutes. Before that happens, though, you’ll probably encounter one or a lot of those seven signs of a failing alternator.

Batteries will fail on their own but dangerous alternators will truly drain them as a result of they’re not recharged. make certain the alternator is checked after you replace the battery to forestall it from going dangerous once more. But do you know How Long Does It Take For A Bad Alternator To Drain A Battery?

Long Does It Take For A Bad Alternator To Drain A Battery

Time Taken For The Bad Alternator To Drain A Battery

In this state of affairs, the battery might last as very little as a half-hour. If you’re lucky and will arise to 2 hours. Note: just in case you’ve got to start the automotive while not an alternator, do not put off the engine once you are going. beginning the automotive flattens the battery down quickly.

How Do I Stop My Battery From Draining Once Off?

  • Using your smartphone’s screen brightness to cut back the battery drain is one of the best ways that to increase its life.
  • You need to stay a watch on your app.
  • You can save battery life by downloading battery saving app.
  • You will close up the WiFi connection.
  • You will activate Airplane Mode.
  • The Location Services are lost.
  • Email your email.
  • Apps ought to be notified less often via push notifications.

What Kills An Alternator?

Running fully charge mode endlessly will kill an alternator, therefore attempting to own your new alternator attempt to charge your dead battery may end up in immediate alternator failure.

Signs Of A Bad Alternator

4 Symptoms of a Faulty alternators

  • The Car Will Not Start: A dead battery nearly always lies behind an automobile that will not begin.
  • Engine Stall: A dead generator nearly always ends up in an automobile that will not begin.
  • Electrical Problems: A dying generator will result in a good variety of different electrical problems.
  • Unusual Sounds

Car batteries will lose their charge for a range of reasons. However, there are four common issues that will cause the battery to empty slowly. If your battery was running fine the last time you drove and currently will not begin the automotive, one among the subsequent issues is also guilty.

Parasitic Drain

If your ignition is turned off however the electrical devices like your radio presets, security alarms, or clocks still run, it will drain your battery. This sort of drain is named a parasitic drain. Parasitic drains below seventy-five milliamps are traditional, however, any parasitic drain over seventy-five milliamps can drain the battery quickly.

The foremost common causes of the parasitic drain are below hood lights, trunk lights, headlights, or glove box lights that don’t shut down once the door is closed. Relay switches that area unit stuck within the “on” position may also cause a battery to drain.

Bad Charging System

A faulty charging system can drain the battery while the automotive is running. Once an alternator isn’t pushing out enough voltage, which ought to be between 13.5 and 14.5 volts, the battery can drain quickly. This can be very true if you play the radio and lights while driving. Once the car battery drains fully, the headlights and radio won’t operate. The automotive can stall and not begin once more till the battery is charged.

Bad Alternator Diodes

Alternators with unhealthy diodes will cause battery drain. alternator generator with a decent diode permits current to flow in one direction. A foul diode will leak and permit the present to flow within the other way. once this happens, it’s going to keep the charging circuit on when the vehicle engine is shut off, which can cause the battery to empty.

Old Battery

Batteries that are recent or are drained continuously might not hold a full charge any longer. The rule of thumb for substitution a battery is each four to 5 years. However, some batteries will last years longer if taken care of and not run down whereas the charging system isn’t running. Batteries that are allowed to freeze over a particularly cold winter can also have issues holding a charge.

Normal Battery Drains Per Hour

It’s very hard to mention what proportion to drain per hour as a result of it altogether depends on usage and settings/apps/etc. I feel it’s higher to live by standby time per hour which means least, if any, usage. for me, I drain about 1% chronicles per hour underneath normal conditions if I’m not using the phone.


The battery, draining is not good for your car so if it is happening you should immediately fix this and for this, you should know what is the reason behind this over-draining of battery? and if the alternator is the reason How Long Does It Take For A Bad Alternator To Drain A Battery?

Frequently Asked Questions

How long can a new car battery last if the alternator is bad?

Even though your battery still works with a nasty alternator, it’ll not last for a jiffy. At most, you’ll get a half-hour of a drive if you’ve got a nasty alternator. therefore, once this happens to you, you should organize the simplest route for the destination you wish.

Can a foul alternator drain the battery overnight?

An unsound or defective alternator diode can faultily continue charging the circuit even once the automotive is off. This, in turn, can drain your car battery and cause the automotive to not begin.

What is draining my car battery once it’s off?

When your car battery discharges presently once move down the engine, it’s ordinarily caused by one among 3 things: Your battery might have reached the tip of its service life (often four or five years). A parasitic drain is depleting battery power. a retardant in an electrical system affects battery power.

Why will my automobile keep dying with a new battery and alternator?

Loose or corroded battery connections, continuous power consumption, charging issues, persistent want for a lot of power than alternators, and even inclement weather are a number of the foremost common reasons for continual automotive battery failures.

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