[C320-list] Battery Bank Upgrade - Which starting battery??

[Warren Updike]

Alan, 1000MCA is more than sufficient as a starting battery. I couldn't find
the reference to the starting current in the Perkins Shop Manual; but, I
didn't think the starting amperage was anywhere near 540A.  The Perkins fuse
on the engine I thought was 80A.  I think the fuse I used on my battery
upgrade is 100A. I doubt you need more than that.  Just make sure you clean
all the connections is the starting circuit at least every year or two
depending on where and how the boat is used. I mean the large cables between
the battery, starter and grounds, not necessarily the light wires between
the starting solenoid and switch.  The big ones carry the heavy current.
Corroded connections greatly increase the load, or so I understand.

I think one of the better upgrades was to change the main switch for a Blue
Sea e-series (5511e) dual circuit switch.  Takes all the bother out of
managing the charging underway.  It switches both the starting and house
banks at the same time: either on or off. No thinking required.

Warren & Pattie Updike
1994 C320 #62 "Warr de Mar"

-----Original Message-----
From: Alan Goodman [mailto:goodmanalanlee at hotmail.com] 
Sent: Friday, March 18, 2011 4:02 PM
To: c320-list at lists.catalina320.com
Subject: [C320-list] Battery Bank Upgrade - Which starting battery??



I am in the midst of upgrading my battery bank following the instructions in
the forum archives.  FYI, based upon cost / benefit ($200 each) I installed
2 Interstate SRM-4D lead acid batteries for the house bank providing a
combined capacity of 410 Ah.  (I know, they are not a pure deep cycle
battery, but readily available without paying huge shipping charges)
I am ready to purchase the dedicated start battery.  I am looking at a Group
24 (11x 6 7/8 x 9 1/2 inch) lead acid rated at 800 CCA and 1000 MCA.
Looking at my Perkins shop manual, the required starting current is 540A.
Does this seem reasonable, or am I reading the spec sheet incorrectly?
Also, assuming 540A is correct, I have been looking for a fuse to install at
the battery "+" (Blue Sea MEGA SEA fuse block p/n 5001), but it seems that
300A is the maximum fuse (per Defender Catalog).  I think that this fuse
rating would be inadequate, any other suggestions?     Alan;  Hull #67;
Holland MI; launching last week of April or first week of May, weather and
ice dependent !!