Will Dead Battery Hurt Alternator?

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The function of an alternator in a car is to engineer the conversion of the mechanical energy of the car engine into electrical energy that recharges the car battery when the engine is running.

Does this however mean that the alternator can be used to recharge a car battery that is completely dead or will it get hurt while trying to do so?

So, will the dead battery hurt the alternator? The primary design of an alternator is not in recharging a dead car battery, rather, it is used to recharge the battery charge while the car is running.

There are various electrical components or gadgets in a car that continuously drains out the battery charge, the job of the alternator, therefore, is to keep on recharging the battery while the car is running.

To recharge a dead battery, it will take an alternator working at its highest capacity, that is, at 100% capacity to do so.

However, alternators are not engineered to be able to withstand working at such capacity for an extended period.

This explains that using an alternator to recharge a dead car battery hurts the alternator and may cause its untimely failure.

So, if an alternator should not be used to recharge a dead car battery, how can a dead car battery be revived?

The safest way to do this will be to take the battery to the car repair shop with the facility of recharging the dead battery. This should be done before connecting the car battery to the alternator.

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Why does a dead battery hurt the alternator?

To understand why this, happens and why you should not attempt to use the alternator with a dead battery, you have to first understand the working mechanism of an alternator and the physics behind how it recharges the car battery.

This way, you will be able to understand why recharging a dead car battery with the alternator is beyond the alternator’s engineering and will get it hurt.

Alternators generate the electrical current that recharges the car battery while the engine is running, but how does it do this? a flashback at elementary physics shows that electrical current can be generated from a magnetic field and a magnetic field can be created from channeling current through a wire coil.

The amount of electricity generated by a coil of wire is proportionate to the magnitude of the magnetic field and vice versa.

This principle is central to the working mechanism of the car alternator. The device is composed primarily of b basic parts; a rotor which spins to create the magnetic field, the voltage regulator which works synergistically with the rotor by sending current to the rotor to be used in creating the magnetic field.

The stator is the part of the alternator which is excited by the magnetic field generated by the rotor to produce an alternating current.

The last component of the alternator is the bridge rectifier, this will finally convert the alternating current generated by the stator into a direct current.

These parts are engineered to work together to generate the current needed to refill the charge in a car battery as the engine runs.

They also work together to generate the electricity that is sent to other parts of the car such as the headlights. 

The amount of alternating current generated by the alternator rotor depends on the load placed on the electrical system.

Whenever there is an additional load, this is sensed automatically by the voltage regular which controls the amount of alternating current the rotor generates.

Let’s say the car headlights are turned on, this is sensed by the system as an increased load which then triggers increased generation of alternating current by the rotor which is then converted by the stator into a direct current which the car can make use of.

So, each time there is an increased load, the voltage regulator senses this and alerts the rotor to increase the amount of current generated and vice versa.

So, why is recharging a dead battery with an alternator something that hurts the alternator? This is because the current requirement of a dead battery is beyond what the alternator can cope with. When a battery runs down, in that state, the car battery can be compared to a vampire thirsty for blood.

A huge amount of current is required to get the battery back on its feet, the alternator is simply not designed for such resurrection, and pulling such stunt with it will simply get it damaged.

To continue to work effectively, the alternator rotates between a state of rest and active current generation, without much rest, the device wears down and may begin to fail.

Saddling the device with such a huge responsibility of recharging a dead battery creates a continuous work cycle without any period of cooling for the alternator which contributes to its eventual breakdown.

A dead battery is therefore one of the primary causes of alternator failure as it forces the alternator to work at its full capacity without cooling for an extended period. Without getting cooled, the alternator is bound to overheat which gets it damaged. 

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Can a dead battery damage the car alternator?

It is a common occurrence to find the car battery completely drained out after overnight parking or after leaving the car parked for several days.

This is commonly due to mistakenly forgetting to put off the indoor lights or other power consumers during this period or as a result of another parasitic battery drain.

A car battery is only required to get the car started; the alternator takes over immediately after. So, if one can get the car started, can the alternator work to get the dead battery recharged without sustaining any form of damage?

There are reports from those who have attempted to pull this stunt and discovered the battery did not get charged with the drive.

Their car mechanics are undecided regarding the cause for a damaged alternator. How true is the claim that an alternator can get damaged this way?

A good number of car owners claim to have used the car’s alternator to recharge a dead car battery back to life without causing any form of damage to their alternator.

A weak battery should however go through deep charging before getting connected to the alternator.

If the alternator fails to charge the dead battery back to life, does this automatically mean the alternator has become damaged? This may not be the case.

There are other reasons or explanations for an alternator failing to charge the car battery, this could be as a result of the battery being dry or damaged.

The only way out for a damaged battery is to get it replaced. It may also be a result of a wiring problem. The wiring connecting the alternator and the battery should be checked for faults, breakages, or loose connections.

Does driving with a dead battery suffice to charge it?

Many car owners and drivers have this belief, that is, by driving the car about, the alternator can charge the dead or flat battery back to full capacity forgetting that this is not the engineering goal of the alternator.

Deep charging a dead battery that has run out of charge completely is a huge responsibility requiring an enormous amount of current which is beyond what the alternator can generate consistently without getting hurt.

Maintaining the battery’s charge while the car runs is what the alternator is originally designed for and not battery resurrection.

The components of the alternator at the most risk of damage when the alternator is placed in such a precarious position are the alternator’s voltage regular and the rectifier.

Car mechanics have recorded numerous cases of the car’s alternator failing as a result of the car owner or driver attempting to make use of the alternator to recharge back to live a dead car battery.

Whenever you have a dead battery, the appropriate thing to do is to get it out of the car, and ensure its water level is adequate, that is, the battery is not dry. Then plug the battery into a wall charger to get it charged. 

There are instances where driving with a dead battery caused no harm to the alternator, indicating that this is not a consistent occurrence.

Therefore, the car can be driven with a dead battery if there is no time to get the battery charged first, such as in an emergency.

Do not be in haste to conclude on alternator failure without running a proper diagnostic test on the alternator. If the voltage output of the alternator is within the normal range, that is, 13.8 to 14.4 volts, then it can be said still be viable.

Will Dead Battery Hurt Alternator – Conclusion

The car alternator generates the current that keeps the car battery charged, it is however for maintaining the battery charge and not for recharging a dead battery.

While driving with a dead battery and expecting the alternator to get it charged back to life may not always hurt the alternator, it is one of the possible causes of alternator failure.

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