Power Supply Calculation for a Car Audio Project with Batteries

September 10, 2025 20:36 Updated

For sizing the power supplies for the system, we use a simple calculation.

In this example, we have a project with 1 MD5000.1 and 1 MD3000, totaling 8,000 WRMS of amplifier power, which would require at least 400 amperes of batteries.

With this minimum battery capacity, we need a power supply that can provide at least 30% of the battery current, so that the system can run almost all day with the power supply connected to the electrical network.

So: 400 amperes × 30% = 120 amperes minimum power supply. One option today would be a Smart Charger 120A to keep this system running.

This is the minimum recommendation for the project. The more batteries and power supplies used to maintain the audio system, the better the results will be.

This is the minimum recommendation for the project. The more batteries and power supplies used to maintain the audio system, the better the results will be.

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