What is the most common cause of AC ripple from an alternator?

The most common cause of AC ripple from an alternator is indeed faulty or low-quality rectifier diodes. Rectifier diodes are crucial components in the alternator that convert the alternating current (AC) produced by the alternator into direct current (DC) suitable for charging the battery and powering electrical systems on the vessel.

When rectifier diodes are functioning properly, they allow current to flow in one direction while blocking it in the opposite direction, which ensures a smooth DC output. However, if the diodes are faulty or of low quality, they may not effectively perform this function. This can lead to incomplete rectification of the AC voltage, resulting in AC ripple superimposed on the DC output. Such ripple can cause various electrical issues, including flickering lights, poor performance of onboard electronics, and reduced battery life due to inconsistent charging.

High-frequency voltage regulators and excessive loads, while they may cause other forms of electrical problems, do not typically lead to AC ripple. High-frequency voltage regulators primarily work to stabilize voltage output rather than influencing ripple. Similarly, excessive load on the alternator could cause voltage drop or strain the electrical system but is not a direct cause of AC ripple.

Faulty battery connections may cause issues like voltage drops or intermittent