I would just use the stock alternator that you have already although having
said that if it came with a 4/108 then its a pretty old one and you would
get a much better charging rate out of a much newer car alternator.

Using gel batteries could be a problem as I dont think they need to be
charged to the same voltage as normal wet batteries because they cannot deal
with the gassing that occurs with normal batteries when fully charged.
Others here may know more about gel batteries

Tony uk


wrote in message
...
I agree a modern, self-contained car alternator is a much better
alternative than this money ripoff boat nonsense with the $300
regulators. Batteries are just too simple...float 'em and they work
great. .

This got my attention.

An older sailboat ('79) I just purchased, has two West Marine SeaVolt
gel batteries and what appears to be the stock alternator that came with
the Perkins 4-108. I see no external regulator.

Should I replace this old alternator? If so, can I use an automobile
regulator? I was pricing exactly what you panned - marine alternators
like Balmar with external regulators and echo chargers linking house to
starting battery.

It certainly would be far cheaper if I could use a car alternator.

TIA for any info.