How Long Will A Battery Last Without An Alternator

If you’re driving around and your car suddenly dies, it’s probably because the battery is dead. This can happen for a number of reasons, but one of the most common is that the alternator isn’t working properly. The alternator is responsible for supplying power to the battery, so if it’s not functioning correctly, the battery will eventually die. This blog post will discuss how long a battery can last without an alternator and what you can do to prolong its life.

How long will a battery last without an alternator?

The alternator is important because it’s responsible for charging the car’s battery and powering all of the electrical systems. It also helps to start the engine by providing extra power.

If your alternator isn’t working properly, you may experience problems like a dead battery, dim headlights, or a system that keeps turning on and off. In some cases, the alternator can even overheat and cause severe damage to your car. So if you’re experiencing any of these issues, it’s important to get your car checked out as soon as possible.

Generally speaking, though, a battery without an alternator will last for a very short time – probably just a few minutes to 30 minutes maximum. Though it’s technically possible for the battery to run without an alternator, this is not always the case, and it is not recommended because it can cause serious damage to your car.

If you’re in an emergency situation and need to use your car without an alternator, make sure to drive carefully and avoid using any electrical components. This includes the lights, radio, air conditioning, and power windows. It’s also important to keep an eye on the battery gauge to make sure that the battery doesn’t die.

If your car is experiencing any of these problems, it’s important to get it checked out by a mechanic as soon as possible. The mechanic can help to diagnose the issue and may be able to fix it without having to replace the entire alternator.

How far can I drive with a dead alternator?

A car with a dead alternator can still drive a few miles, but it won’t be able to run any electrical devices, including the headlights. After a while, the battery will also die. How long it takes depends on how much juice was left in the battery when the alternator died and how fast you’re driving. If you’re lucky, you’ll make it to a service station before your car dies completely.

If your alternator dies while you’re driving, the first thing you’ll notice is that your lights will start to dim. If you’re driving at night, it’s best to pull over immediately and turn on your hazard lights. Once you’ve pulled over, turn off any electrical devices that are running, including the radio and the air conditioner. This will help prolong the life of your battery. If you can’t get to a service station right away, try to find a safe place to park your car. Once you’ve done that, call for help.

If you’re not driving at night, you may call a technician to come to you and jump-start your car. This will give your battery the boost it needs to get going again. You should still drive to a service station as soon as possible so that they can test your alternator and make sure it’s working properly.

Remember that a failing alternator is inconvenient, but it’s also a safety hazard. If your alternator isn’t working, you may not be able to start your car or keep the battery charged. This could lead to an accident, so it’s important to get it fixed as soon as possible.

How long does a 12v battery last without alternator?

A 12 volt battery will last for about 30 minutes or less without an alternator. If you have a bigger battery, it might last longer. If you have a smaller battery, it won’t last as long. Alternators help keep the battery charged, so it lasts longer. Without an alternator, the battery will eventually die.

It is always best to keep every part of your car in good condition to avoid any problems. This way, you can be safe on the road, and your car will last longer.

Can a car continue to run without an alternator?

Technically, a car could run without an alternator as long as there was another way to generate electricity. However, it’s not advisable to do so because the battery would eventually die, and the engine would have to work harder than it should in order to generate power.

When this happens, the engine can overheat, which would lead to further problems. In most cases, it’s best to have a working alternator in order to keep the car running smoothly and efficiently.

However, there are a few things you can do to try to keep your car running in a pinch if you’re stranded and don’t have access to a replacement alternator. You can try jumping start it using another car battery, or you can try to bypass the bad alternator altogether by jumper cables and run the car off of battery power only. But both of these solutions are just temporary measures, and your car won’t be able to run for very long this way. Ultimately, you’ll need to replace the bad alternator in order to keep your car running properly.

What happens if you disconnect the alternator?

If you disconnect the alternator, your car will not be able to generate electricity, and it will eventually run out of power and die. The battery can provide power for a short amount of time, but eventually, it will also run out of power, and the car will stop functioning. So it is not possible to do driving without an alternator.

One important thing to note is that when you disconnect the alternator, you are also disconnecting the car’s electrical system. So if you do this while the car is running, you will likely blow a fuse and disable the entire electrical system. It’s important to be very careful when working with car wiring because even a small mistake can result in serious damage.


So, now you know a little more about alternators and their importance in your car. If it starts to make strange noises or seems like it’s not working as well as it used to, don’t hesitate to take it to a mechanic for a check-up. It could save you from expensive repairs down the road.

About the author, Phil Borges

Phil Borges is a battery aficionado. He's written extensively about batteries, and he loves nothing more than discussing the latest innovations in the industry. He has a deep understanding of how batteries work, and he's always on the lookout for new ways to improve their performance.