A lot of people think that if they have a good alternator, their battery will never die. This isn’t always the case. In this blog post, we’ll take a closer look at the relationship between batteries and alternators, and try to explain why a car battery can die even with a good alternator.
Key Takeaway
- If the battery can’t hold a charge, it doesn’t matter how good the alternator is. The battery will still die.
- A bad alternator can ruin a good battery by overcharging it. This happens when the voltage reader isn’t working.
- A new battery can last up to six months with a bad alternator.
- If you replaced a bad alternator, it is best if you change the battery as well. There is a good chance that the bad alternator damaged the battery cells over time.
- A new alternator can’t drain an old battery. It is more likely that the old battery isn’t able to hold a charge anymore.
Can a Battery Die With a Good Alternator?

The alternator is a crucial component in any car. Its purpose is to generate electricity to power the car’s electrical system and to recharge the battery. The alternator is powered by the engine, and it produces alternating current (AC). The AC is then converted to direct current (DC) by the rectifier, which is a set of diodes. The DC powers the car’s electrical system and charges the battery.
A car battery can die with a good alternator. Alternators maintain the charge in the battery and recharge it as needed while the engine is running, but in order to do so, the battery has to be able to hold a charge. Batteries can die for a number of reasons, including age, corrosion, cold weather, and overcharging. Even if the alternator is in perfect working condition, the battery may not be able to hold a charge.
Over time, car batteries will gradually lose their ability to hold a charge. This is due to a number of factors, such as the breakdown of the battery’s internal structure and the accumulation of deposits on the electrodes. In this case, the battery will die, regardless of how good of a job the alternator does.
While there is no way to completely prevent a battery from degrading, keeping it clean and maintaining proper charging habits can help to extend its lifespan. For example, using distilled water to top off the battery’s electrolyte level and avoiding deep discharge cycles can help to prevent some of the damage that causes batteries to age. Ultimately, though, all batteries will eventually reach the end of their lifespan and need to be replaced.
Can a Bad Alternator Ruin a Good Battery?

The lifespan of an alternator can vary depending on a number of factors, such as the make and model of the vehicle, the driving habits of the owner, and the quality of the alternator itself. In general, however, most alternators will last for around 100,000 miles before it goes bad. Many car owners wonder if a bad alternator can ruin a good battery.
A bad alternator can indeed ruin a good battery. If the alternator is not charging the battery properly, the battery will be strained and will eventually fail. Additionally, if the alternator is putting out too much voltage, it can damage the battery cells, shorten their lifespan, and cause them to fail.
There are a few ways an alternator can go bad. One way is if the bearings seize up. The bearings allow the alternator to spin freely on its axis. If they seize, it puts extra strain on the engine and can cause it to overheat and fail.
Another way an alternator can go bad is if the brushes wear out. The brushes are what conduct electricity from the spinning rotor to the stator windings. If they wear out, it can cause a drop in voltage output, and eventually, the alternator will fail.
Finally, an alternator can go bad if the rectifier fails. The rectifier converts Alternating Current (AC) into Direct Current (DC). If it fails, it will no longer be able to do this conversion, and the alternator will fail.
It’s important to have your alternator checked regularly to ensure that it’s in good working condition. If you think your alternator might be going bad, take your car to a mechanic for a diagnosis.
How Long Will a New Battery Last With a Bad Alternator?

A new battery will last for up to five years with a good alternator. But, what if you changed your car battery thinking that it was the culprit, instead it turned out that the alternator was causing the issues? How long will a new battery last with a bad alternator?
A new battery will last anywhere from six months up to a year with a bad alternator. When an alternator starts to fail, it puts strain on the battery as it attempts to keep up with the demands of the electrical system. This extra strain will cause the battery to degrade faster, eventually leading to complete failure.
Even though a new car battery should last much longer, it won’t be able to withstand the strain of a faulty alternator for a long time.
Without a working alternator, your car battery will eventually die. The alternator is responsible for recharging the battery while the engine is running. If the alternator fails, the battery will slowly lose its charge and eventually die. Without a working battery, your car will not be able to start.
There are several symptoms of a failing alternator, including dimming headlights, flickering dash lights, and slow cranking when you try to start the engine. If you notice any of these symptoms, it’s important to have the alternator checked as soon as possible. A failed alternator can damage the battery and cause other electrical problems in your car.
Replacing a bad alternator can cost between $100 and $250 while replacing a battery can cost between $50 and $250. Either way, it is better to first check the alternator before replacing your battery.
Do I Need a New Battery After Replacing The Alternator?

An alternator is a vital component of a car’s electrical system, converting mechanical energy into electrical energy to charge the battery and power the vehicle’s electrical equipment. When an alternator goes bad, it can cause a number of problems.
First, the battery will not be able to hold a charge, and the car will eventually lose power. Second, the car’s lights may dim or flicker as the electrical system struggles to function. Third, the car may experience strange noises as the alternator fails to operate properly. Finally, the engine may stall or shut down entirely if the alternator is not working.
Once you replace the alternator, you may wonder if you need to replace the battery as well. Whether you will need to replace the battery after replacing the alternator will depend on how long you have driven the car with a bad alternator and how many times was the battery completely drained.
If you had a bad alternator for a long period of time (up to a few months) and the car battery was completely drained more than a few times, you may need to replace the battery as well after replacing the alternator. When an alternator goes bad, it can either not charge the battery properly and cause it to be strained, or it can put out too much voltage and damage the battery cells.
This is why I strongly recommend that you replace the car battery with a new one after replacing a bad alternator. There are ways to test the battery, but it is better if you just start fresh with both the battery and the alternator.
Can a New Alternator Drain An Old Battery?

It is very rare for a new alternator to drain an old battery. The more reasonable explanation is that the battery is too old and with damaged cells that can no longer hold a charge. No matter how good the alternator is, the old battery will simply never receive the charge.
A new alternator can, in some cases, drain an old battery. This is because the alternator is designed to keep the battery topped off at all times. When the engine is running, the alternator produces electricity to power the vehicle and also recharge the battery. If the battery is old and unable to hold a charge, the alternator will constantly be working to recharge it, which can cause it to overwork and overheat.
When a car battery goes bad, it no longer produces the necessary amount of power to start the engine. This can be caused by a number of factors, including corrosion, a build-up of sulfate on the plates, or simply age.
In some cases, a bad battery may still be able to hold a charge, but it will not be strong enough to power the engine. If you suspect that your battery is going bad, it’s important to have it checked by a mechanic as soon as possible. A bad battery can damage the starter and other electrical components, and it can also be a fire hazard.