[C320-list] Inadequate Dedicated Starting Battery

[Jeff Hare]

The problem you're seeing is that you chose a Deep Cycle battery.  (Duralast G27 Marine battery) You should not use a Deep Cycle or dual purpose starting/deep cycle as your starting battery. You want a true starting battery.  Deep Cycle and duals have thicker plates intended to be drawn down and cycled. As a result, they have much lower max current availability in exchange for lower currents over a longer period of time.  Starting batteries are intended to see high current for short periods of time and then be topped back up quickly by the alternator.

My choice for starting battery is the highest CCA AGM starting battery you want to afford that fits your available space. It'll last the longest, require zero maintenance and won't let you down.

-Jeff Hare

-----Original Message-----
From: C320-list <c320-list-bounces at lists.catalina320.com> On Behalf Of Bob Hoyt
Sent: Tuesday, December 7, 2021 8:54 AM
To: c320-list at lists.catalina320.com
Subject: [C320-list] Inadequate Dedicated Starting Battery

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*

*Richmond, VA*


*CAPT (Ret) USN*

InformaticsEducation.org  <http://InformaticsEducation.org> rehoyt at gmail.com

Cell: 850-384-5235