I think my alternator (amp output unknown) and 'next step smart regulator' are cooked and am just curious to see what engine charging system is used by others. My engine is a 36 Bukh with a 460 amp hour battery bank and starter battery. Would , say a 100 amp alternator with internal regulator suffice or do I need to use a smart external regulator ? Would probably run engine, and hour or two each at a time and then sail. Thanks for your help.

I have a similar sized battery bank - and run a 60A non smart alternator. Ramona is correct, without a smart regulator alternators will charge at about 50 amps for a few minutes and then drop back to 20-25amps.

The problem is that these non-smart regulators generally regulate to around 13.8 - 13.9V.

A smart alternator controller will allow bulk charging at full alternator discharge to 14.2V before regulating back to adsorption 13.8V. This does speed up charging ability significantly. They also often have a heat sensor on the batteries to regulate charging depending on temperature.

The reason that I don't want or need a smart regulator is that solar charging is by far and away the most efficient means of keeping your batteries topped up. Depending on your load, 200-500W of solar panels and you may never need your alternator again. MPPT regulators all have bulk / adsorption / float ability which assists quick charging.

Then use your dumb regulator as backup.

I ruined two battery banks in my last boat from a wayward smart regulator (cooking batteries) before going to this system and never having a problem again. I also use a wind gen as back-up or for overcast / night time charging.