Installing an 12V 600W Electric A/C Compressor: Battery and Alternator Requirements

Introduction to Electric A/C Compressors in Cars

Are you planning to install an 12V 600W electric A/C compressor in your car? Proper battery and alternator selection is crucial to ensure a smooth and safe installation. This guide will help you understand the necessary specifications for your project.

Step-by-Step Guide to Determine Battery and Alternator Requirements

1. Calculate the Current Draw of the Compressor

First, you need to calculate the current draw of your 600W compressor. Using the formula:

Current (I) Power (P) / Voltage (V)

For a 600W compressor at 12V, the calculation is:

I 600W / 12V 50A

2. Battery Amp Rating

When choosing a battery for your electric A/C compressor, consider the following factors:

2.1. Continuous Current Draw

Your compressor will draw 50A continuously. It's essential to select a battery that can handle this draw without causing significant voltage drop. This ensures the compressor operates efficiently and safely.

2.2. Reserve Capacity

For extended use, especially when running the compressor without the engine running, consider a deep-cycle battery. A deep-cycle battery can provide the required reserve capacity.

A general rule of thumb is to choose a battery that can provide at least 1.5 to 2 times the continuous current draw. Therefore, look for a battery rated for at least 75A to 100A.

3. Alternator Amp Rating

Your alternator needs to supply enough current to support the compressor and other electrical components in your vehicle.

3.1. Total Current Demand

Assume an additional load of about 20A for other accessories such as lights, radio, etc. The total current demand would be:

Total Current 50A (compressor) 20A (other loads) 70A

3.2. Alternator Rating

To ensure the alternator can handle the load and still maintain a charge in the battery, it's advisable to have an alternator rated for at least 1.5 times the total current demand. Therefore, you should look for an alternator rated at 100A or higher.

Summary

Here's a summary of the key points:

Battery Rating

At least 75A to 100A is required. Consider a deep-cycle battery for extended usage and better performance.

Alternator Rating

At least 100A to support the compressor and other electrical loads.

Additional Considerations

1. Wiring

Ensure that you use appropriately sized wiring to handle the 50A load safely. This prevents electrical interference and ensures a reliable connection.

2. Fuse Protection

Install a fuse or circuit breaker rated slightly above the compressor's current draw to protect the wiring and components from potential damage.

3. Cooling

Make sure that the compressor and battery have adequate ventilation to prevent overheating. This is crucial for long-term performance and safety.

By following these guidelines, you should be well-prepared for your A/C compressor installation, ensuring a smooth and efficient setup for your vehicle.