What Size Alternator Do I Need?

In order to determine what size alternator you need, you’ll need to know what your car’s power requirements are. Here’s a look at how to figure out your car’s power requirements and find the right alternator for the job.

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An alternator is a device in a car’s engine that generates electricity to charge the battery and run the electrical accessories. The size (also called the power) of the alternator is measured in amperes (amps).

To work out what size alternator you need, you first need to know what your car’s maximum power requirements are. You can find this information in your car’s handbook.

If you’re fitting extra electrical equipment, such as a towbar or a winch, you’ll need to take this into account too. The table below shows some typical maximum power requirements:

Type of car Maximum power required (amps)
Small family car with base audio 60-70
Small family car with premium audio 80-90
SUV or minivan 100-120
Large family sedan or wagon 110-130
Sports car 130-150

How to determine the size of the alternator?

It is important to have an alternator that can keep up with the electrical demands of your vehicle while also providing reliable power. There are a few factors to consider when purchasing an alternator.
-The first is the maximum amperage output. This is the amount of power that the alternator can provide at any given time.
-The second is the cranking amps or cold cranking amps. This is the amount of power that the alternator can provide when starting your vehicle in cold weather.
-The third factor to consider is the voltage output. You want to make sure that the alternator can provide enough power to keep your battery charged and running at its optimum level.

You can find the size of your vehicle’s alternator in your owner’s manual or by contacting your local dealership.

What are the benefits of a larger alternator?

A larger alternator has a number of benefits over a smaller unit. First, it can provide more power to accessories. This is especially important if you have a lot of electrical items running at the same time, such as a winch, off-road lights, and a stereo system. Second, a larger alternator can recharge the battery faster after it has been depleted. This is important if you frequently use accessories that drain the battery, such as a winch or an air compressor. Finally, a larger alternator will last longer than a smaller one because it is not working as hard to provide power.

What are the benefits of a smaller alternator?

A smaller alternator is typically more efficient and puts out less heat. Less weight can mean a lower center of gravity, improving handling. Since there are fewer parts in a smaller alternator, it may be more reliable.

How to choose the right size alternator for your car?

There are a few things to consider when shopping for a new alternator. First, you need to know the make, model, and year of your vehicle, as well as what kind of engine it has. Alternators come in different sizes, so you’ll need to make sure you get one that’s compatible with your car. You also need to decide what level of quality you want. The three main levels are economy, standard, and premium. Finally, you need to decide how much power you need. The most common options are 55 amps, 65 amps, and 75 amps.

Once you’ve gathered all this information, you’re ready to start shopping for your new alternator. The best place to start is with an online retailer such as Amazon or eBay. You can also check with your local auto parts store or dealership.


As you can see, there are a variety of factors that go into determining what size alternator you need. If you have any questions, it’s always best to consult with a professional or an expert in the field before making your purchase.