Alternator, Regulator, or just me?

[emkopes]

All-

Hello, new boat owner (and learning a lot) but have a first real issue with electrical and just looking for advice on the best way forward and most likely causes.

Ericson 35, Balmar ARS II, not sure on the alternator (see photo). Simple 3 battery bank.

Symptom: Start engine, idles for 30-40 seconds and regular kicks the alternator in, loads for 3-5 seconds, battery voltage spikes, regular kicks off line. Repeats every 30-40 seconds. No LEDs light up on the ARS II at any time. I am at the dock and the batteries are basically "charged" ... the overall kicking off/on is not subtle, the engine RPMs drop pretty drastically but doesn't approach stalling.

Recent maintenance: I recently changed the belt, size matched previous, no belt squeal though I tensioned more and less with no change in behavior overall as part of seasonal maintenance.

Thoughts? What additional information should I be looking at to help find the root cause? I know know if I saw LEDs on the regular in the past .... something I wish I had paid attention to previously.

Thanks in advance for any of your thoughts!

Eric

[Sailmonkey]

Discharge your batteries, or turn on all the lights or something similar to pull some current out of the batteries.

It sounds to me like your batts are completely charged and the regulator is attempting to charge them. We have an ample power regulator that behaves similarly when the engine is running and the wind/solar have raised the voltage.


Sent from my iPhone using Cruisers Sailing Forum

[DeepFrz]

You say that the voltage "spikes". What voltage do you see during these "spikes"? It sounds like the regulator isn't working properly.