Roger Long wrote:
I understand that but, is the load on a 20 hp diesel that you can
start by hand high enough to significantly reduce the life of the
battery?


What's the voltage drop when starting? Starting batteries can see surges
bring them down to as low as 8 volts and bounce back just fine. DC
batteries don't like this.

I'm not sure where the cut-off is, but if the starting load drops your
voltage down below 10, or maybe 10.5 (assuming that you've got a good
current path to starter & ground), then you might consider staying with
a start battery.

Fresh Breezes- Doug King

I'll let you know when I get the boat

My first two batteries are free, (and therefore probably minimum
quality) when the boat is delivered. Since this boat will seldom, if
ever, see shore power and often sail on and off its mooring, one of my
first projects will be a complete upgrade of the whole power system.
This will probably involve moving to sealed batteries in the bilge
since these boats are stern heavy and a bit tender. I'll also probably
put in a solar trickle system.

--

Roger Long



"DSK" wrote in message
...
Roger Long wrote:
I understand that but, is the load on a 20 hp diesel that you can
start by hand high enough to significantly reduce the life of the
battery?


What's the voltage drop when starting? Starting batteries can see
surges bring them down to as low as 8 volts and bounce back just
fine. DC batteries don't like this.

I'm not sure where the cut-off is, but if the starting load drops
your voltage down below 10, or maybe 10.5 (assuming that you've got
a good current path to starter & ground), then you might consider
staying with a start battery.

Fresh Breezes- Doug King

On Wed, 12 Jan 2005 12:24:16 GMT, "Roger Long"
wrote:
I'll let you know when I get the boat

My first two batteries are free, (and therefore probably minimum
quality) when the boat is delivered. Since this boat will seldom, if
ever, see shore power and often sail on and off its mooring, one of my
first projects will be a complete upgrade of the whole power system.
This will probably involve moving to sealed batteries in the bilge
since these boats are stern heavy and a bit tender. I'll also probably
put in a solar trickle system.

===========================================

With my last boat I used 6 volt golf cart batteries for both starting
and a house bank driving a large inverter. The engines were 350 hp,
454 cubic inch V8s, and they never had a problem cranking, even in
freezing weather.