100 Amp Alternator Vs 70 Amp: A Comprehensive Comparison

If you need a new alternator but are confused between a 100 Amp alternator and a 70 Amp alternator, this article is for you. We have done a comprehensive review of 100 Amp Vs. 70 Amp Alternators, and by the end of this article, we hope you will not be in a dilemma.

In this article, we will be discussing the mentioned alternators. Both alternators have a huge fanbase for their durability and precise functionality.

We have explored the differences and suitability of the alternators for different vehicles. We have also mentioned the installation process and maintenance tips, cost considerations, and customer feedback of 100 AMP and 70 AMP Alternators.

Why choosing a suitable alternator is important?

If you are reading this article, you already know what an alternator is and how important it is for your vehicle. An alternator charges the battery and gives power to a number of different electrical systems.

If you choose an alternator that is not designed for your vehicle, you run the risk of damaging your battery and other electrical components in the long run.

The 100AMP and 70AMP alternators are very popular in the market due to their quality and dependability of the alternators. Before we compare the alternators against one another, let’s first take a more in-depth look at each one individually.

100 Amp Alternator Vs. 70 Amp


Overview of 100 Amp Alternator

A 100 amp alternator, as the name suggests, has an amp rating of 100 amps. This rating refers to the maximum electrical current it can produce. This indicates the alternator’s output capacity.

A higher amp rating means the alternator can provide more power to meet the electrical demands of the vehicle. But here is the catch: it can provide more power, but it is unsuitable for all types of cars.

A 100 amp alternator is typically found in larger vehicles or those with additional electrical accessories. If your car has high-end sound systems or aftermarket lighting, The 100 amp can be a perfect fit for your car.

The benefits of a 100 amp alternator include its ability to handle higher power requirements. A 100 AMP alternator will ensure a consistent power supply even under heavy loads.

This alternator is suitable for vehicles that need to power multiple accessories simultaneously. This 100 AMP will provide stability and prevent potential power shortages.

Overview of 70 Amp Alternator

On the other hand, a 70 amp alternator has a lower amp rating of 70 amps. The alternator is designed for vehicles with lower power requirements or those without extensive electrical accessories.

A 70 amp alternator is commonly found in compact cars or older vehicle models. Typically the old vehicles have comparatively less electrical power requirements and a minimalistic sound system or just a stereo.

Despite its lower amp rating, a 70 amp alternator still serves its purpose effectively for vehicles with fewer electrical demands. It provides sufficient power to keep the battery charged and supports essential systems like lights, ignition, and basic electronics.

Key Differences Between a 100 Amp Alternator and a 70 Amp Alternator

When comparing a 100 amp alternator and a 70 amp alternator, several key differences become apparent. One of the most significant differences lies in their output capacity and performance.

Output Capacity

A 100 amp alternator can handle higher power demands without strain, ensuring a stable power supply to the vehicle’s electrical systems. In contrast, a 70 amp alternator may struggle to meet the requirements of vehicles with extensive electrical accessories or power-hungry components.

Type of vehicle

Another crucial factor to consider is the suitability of each alternator for different vehicle types. While a 100 amp alternator is ideal for larger vehicles or those with additional accessories, a 70 amp alternator is better suited for compact cars or older vehicle models with limited electrical demands.


It’s essential to consider the compatibility of each alternator with the vehicle’s electrical system. Installing an alternator with an incompatible amp rating can lead to potential electrical issues and system malfunctions. Therefore, it’s crucial to consult the vehicle’s manual or seek professional advice before making a decision.

Which Alternator is Right for You?

Choosing the right alternator depends on several factors.

Step 1: First, you need to assess your vehicle’s power requirements and determine whether the existing alternator meets those needs.

Step 2: If you frequently experience power shortages or struggle to power all your accessories simultaneously, upgrading to a 100 amp alternator might be a wise choice.

Additionally, if you plan to add more electrical accessories or upgrade existing ones in the future, a 100 amp alternator provides headroom for expansion. It ensures that your vehicle’s electrical system can handle the increased power demands without compromising stability.

However, if your vehicle has minimal electrical requirements, a 70 amp alternator is likely sufficient to meet your needs. Upgrading to a higher amp alternator without needing it may result in unnecessary expenses and potential compatibility issues.

Installation and Compatibility

When installing a 100 amp alternator, ensure that your vehicle’s electrical system and wiring can handle the increased power output.

Consult a professional or refer to the alternator’s installation instructions for specific guidance. It’s crucial to follow proper installation procedures to avoid electrical hazards or damage to the vehicle’s electrical system.

Similarly, if you opt for a 70 amp alternator, ensure compatibility with your vehicle’s electrical system. Proper installation is vital to prevent any electrical issues and ensure the alternator functions primarily.

Maintenance and Longevity

Proper maintenance is essential for both a 100 amp alternator and a 70 amp alternator.

  1. Weekly inspect the alternator
  2. Check for loose connections
  3. Ensure the drive belt is in good condition.
  4. Keep the alternator clean and free from debris to prevent overheating.

A 100 amp alternator, given its higher capacity, may generate more heat during operation. Therefore, it’s crucial to monitor its temperature and address any overheating issues promptly.

Similarly, a 70-amp alternator requires periodic maintenance to ensure optimal performance and longevity. Remember, an alternator has a great impact on your car battery and the electrical functions of your car.

In terms of lifespan, both alternators can have a long service life if properly maintained. However, the actual lifespan may vary depending on usage, operating conditions, and the quality of the alternator itself.

Cost Considerations

Cost is an important factor to consider when comparing a 100 amp alternator and a 70 amp alternator.

Generally, a 100 amp alternator tends to be more expensive due to its higher output capacity and suitability for larger vehicles. It offers enhanced performance and power capabilities, which can translate to a higher price tag.

On the other hand, a 70 amp alternator is typically more affordable and suitable for vehicles with lower power requirements. It provides adequate power for basic electrical systems without incurring unnecessary costs.

When assessing the cost, it’s important to consider long-term implications as well. While a 100 amp alternator may have a higher upfront cost, it can potentially save you money in the long run if you plan to upgrade or add more electrical accessories.

Customer Reviews and Feedback

To gain further insights into the performance and reliability of both alternators, it’s beneficial to consider customer reviews and feedback. Real-life experiences from users can provide valuable information about the pros and cons of each alternator.

Customer feedback of 100AMP Alternators

Customers who have upgraded to a 100 amp alternator often praise its ability to handle higher power demands without compromising performance. They highlight the stability and peace of mind it offers, particularly for vehicles with numerous electrical accessories.

Customer feedback of 70AMP Alternators

For those using a 70 amp alternator, reviews generally highlight its reliability for basic electrical needs. Customers appreciate its affordability and compatibility with vehicles that don’t require extensive power.

Final Words

In conclusion, choosing between a 100 amp alternator and a 70 amp alternator depends on your vehicle’s power requirements and electrical demands. In short, consider the following factors before purchasing an alternator for your car.

  • Installation
  • Compatibility
  • Maintenance
  • Longevity
  • Cost considerations

Assess your vehicle’s needs and consult professionals if necessary to ensure you choose the alternator that best meets your requirements.


Can I upgrade my vehicle from a 70 amp alternator to a 100 amp alternator?

  • Yes, it is possible to upgrade your vehicle’s alternator from a 70 amp to a 100 amp rating. However, it’s important to ensure compatibility with your vehicle’s electrical system and consult a professional for proper installation.

How do I determine the amp rating of my current alternator?

  • You can check your vehicle’s manual or consult a professional to determine the amp rating of your current alternator. Alternatively, the amp rating may be labeled on the alternator itself. So do check the labels.

Can a 100 amp alternator damage my vehicle’s electrical system if it’s not needed?

  • As long as the 100 amp alternator is properly installed and compatible with your vehicle’s electrical system, it should not damage the system even if it’s not fully utilized. The alternator will provide the necessary power as per the system’s requirements. But it’s better not to do so.

Are there any safety concerns when upgrading to a higher amp alternator?

  • Yes there is. Safety concerns can arise if the upgraded alternator is not properly installed or if the vehicle’s electrical system is not compatible. It’s crucial to follow proper installation procedures and consult professionals to ensure safety and avoid any potential issues.

Can I use a 70 amp alternator for heavy-duty applications?

  • It is generally not recommended to use a 70 amp alternator for heavy-duty applications that require higher power output. A 70 amp alternator is designed for vehicles with lower power demands and this sort of alternator may not be able to handle heavy loads effectively.

Leave a Comment

Your email address will not be published. Required fields are marked *