New starting/house batteries

bshock

bshock

.
Jan 18, 2013
126
Beneteau 361 Sandusky Harbor Marina
Hi All,

I have a B361 with a Westerbeke 30B3 diesel engine and I have to replace the starting battery. Does anyone know how many cranking amps is appropriate for that engine? I tried to find something in the manual that says what to get, but no dice there. My marina's service center is quoting me a 1000 CCA 4D starting battery by Crown Batteries.

I'm also replacing my 4D house battery, and the service center is recommending a single Group 27 75 Ah deep cycle battery. That seems kind of low to me, however we don't have AC, heat, or a fridge and would only use the house battery to power lights and instruments.

I had thought I could put in two 4D deep cycle batteries, one would essentially be dual purpose serving as both the starting battery and a house battery. But that's not what the service center is suggesting.

Any insight is greatly appreciated. :)
 
C

Captn TJ

.
Nov 24, 2012
586
My practice is always to have a engine battery that is isolated from the house side. A 4d would be overkill for the engine. On our 42 we have a 27 for the engine and 2 4D for house.
 
Ron20324

Ron20324

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Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Are you sure those battery numbers are not transposed? 27 to start, 4d for house?
 
Maine Sail

Maine Sail

.
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
Even a personal watercraft battery can start your engine. A 4D is gross overkill. Even the smallest group 24 deep cycle battery would be fine as a starter.. Put the Ah's into your house bank not the starter...

If you had a sport fishing boat with twin 3208 Cats then a 4D would be a suitable choice...
 
bshock

bshock

.
Jan 18, 2013
126
Beneteau 361 Sandusky Harbor Marina
Thanks All, and those numbers were not transposed. I thought it was odd too. I'll talk to the service center and get a 4D deep cycle for the house.
 
joker460

joker460

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Apr 27, 2010
968
Beneteau 352 Hull #276 Ontario
My boat came with a Deka Intimidator AGM 27 starter battery and 2 - 8D House batteries.
 
J

Joe2954

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Jan 22, 2008
169
Beneteau 343 Saint Helens, Oregon OR
To give you a ballpark number the starter in a 3YM30 is rated for 250 amps at 8V under load. Service manual states 12V64ah but it should be spec'd in cranking amps.
Mine came with Gp 24 dual.purpose.
House is wired to four 6vGC. Batteries combine when key switch is on but am plannijng to switch out relay to keep from boiling out starting battery when bowmar goes into equalize.
 
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