"MC" wrote in message
...
I have a two year old Interstate brand marine starting battery. It has not
been holding a charge suffiecient to start the engine. The battery is only
used to start the engine and is not used to power any accesories when the
engine is not running. It is stored out of the boat in my basement for the
winter and is then connected to a Guest brand trickle charger. I have
charged the battery out of the boat using an external battery charger in
an attempt to determine whether or not there is some sort of unknown drain
on the battery when it is not in use,, but the battery will not take a
charge strong enough to start th engine. The battery boasts a two year pro
rated warranty and as luck would have it, two years ended last month!

My question for the group is what is the average life expectency of a
marine
battery? Should it be longer than two years? Anyone have a preference on a
good brand of replacement battery?


If kept fully charged, yes, a starter battery can give you 8 years, or,
more correctly, a few thousand starting cycles. Let it discharge, and stay
discharged for a week or more and it will slowly lose capacity through
'sulphation', a hardening of the chemicals on the plates.

Check the Cold Cranking Amps (CCA) rating of your battery and make sure it
meets the engine manufacturer's requirement. you don't mention your engine
type, but a 4 cylinder 2 litre diesel would typically need about 600CCA.
Engine handbook should give the figure.

If you're using a 'marine' battery for starting, there is a possibility it's
been designed for deep cycle use. Deep cycle batteries won't tolerate high
amp draw down, and they'll soon die if used as starter batteries, but this
should show as a low CCA figure.

Most battery brands are pretty reliable if you've got the right battery for
the job, and if you keep it well charged (and topped up with de-ionised
water) all its life.
--
Jim B, Yacht RAPAZ,
Summers in the Med, winters in UK
jim[dot]baerselman[at]ntlworld[dot]com