[C320-list] Inadequate Dedicated Starting Battery

[P.F. Ross]

Bob,

I did the same thing you did a couple of years ago, 4 ea 6v golf cart batts
with a Group 24 (I think, away from boat and my schematics right now)
starting batt.

I used the existing two each 1/0 cable runs to connect the new batt systems
(one system being the series/parallel 6v batts, and the other system being
the new starting batt) to the rest of the boat.

I am not sure where you get the 4ga cable.  If I recall, the only 4ga cable
in that area is a black ground that goes forward to the winch.

In any case, if the cable from your start batt is 4ga, that would cause a
big voltage drop when the starter is drawing mucho amps.  There are online
calculators that would give you an idea of that drop.

Regards,

Frank Ross
Beta Wave #206
Naples, FL

On Tue, Dec 7, 2021 at 7:54 AM Bob Hoyt <rehoyt at gmail.com> wrote:

> I recently installed a Duralast G27 Marine battery to serve as a dedicated
> starting battery to go with my house batteries (4 six-volt golf cart
> batteries in series). I installed it just forward of the starboard battery
> compartment. The existing cables are listed as 4 gauge, so I thought they
> were adequate.
> With a fully charged new battery and either a cold or warm engine, the
> motor will barely turn over. With the battery selector on all, it starts
> quickly. Is the group 27 battery underpowered or do I need to change the
> wire from the battery to the main switch and wire from the switch to the
> starter motor to 2 gauge? Thanks
>
> Bob Hoyt
> Hull 154
> 1994 C320 "Ikigai"
> Pensacola, Fl
>
>
> --
>
> *Robert (Bob) Hoyt MD, FACP, FAMIA, ABPM-CI*
>
> *Associate Clinical Professor, Department of Internal Medicine*
>
> *Virginia Commonwealth University*
>
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>
>
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