"CCred68046" wrote in message
...
The biggest reason that voltage climbs so high on an unregulated system
is
that the battery is too small a capacity, and/or is a sealed or
"maintenance
free" version. You want a "flooded cell" battery, the largest you can fit
and afford, to run your boat's electrics.

Hey, good to see your still in the group Bill!
I have tried several batteries... I'm currently running a group 27
1000cca. I
have tried 3 BIG non maintenance free batteries. Everyone of them did
the
same thing.


What make, model, year outboard do you have?

Most modern batteries cram a lot of CCA (cold cranking amps) into the
design, but with a loss of reserve power. You want a battery with high
reserve minutes, above 200, and that will absorb the excess voltage. Imagine
charging a small garden tractor or motorcycle battery at a constant 6 amps,
the voltage would climb and it would boil away after a short time. Now
charge a huge bus or truck battery, like an 8D, and your voltage may not
even rise above 14.

A group 27, 30, or 31 deep cycle battery, as long as it meets your engine's
CCA requirement, works a lot better than a "new high tech, quick start"
battery, on unregulated systems.

Bill Grannis
service manager