[C320-list] Couple of start Battery questions

[Mark Cole]

I added a start battery to my boat a couple of years ago and went with a Group 27, 100AH, 640CCA and it has worked fine.  I made a note that a starter usually draws (engine cubic inches x 2) amps and for my Perkins M30 that was 60ci x 2 = 120 amps, so I used 0 AWG wire from the battery to the starter.

You might also want to take a look at a dual circuit switch like the Blue Seas 5511a.  This switch has separate circuits for the start battery and the house bank permanently wired (no A/B setting) so the start battery is always connected to the starter and the house bank is always connected to the DC distribution panel.  No need to change the selector at all and no chance of drawing down the wrong bank, unless you need to combine both banks.  Big plus is that it is the exact same size as the DC battery switch on the 320 panel and is easy to change out.

Mark Cole
Fiddler’s Green #8
Puget Sound

> On Jan 27, 2019, at 3:08 PM, Stephen Cox <scox at timmin.com> wrote:
> 
>> 
>> I just need to make sure I have a Start Battery large enough 
>> to crank the Yanmar 3GM30F.
>> 
>> 
>> 
>> FYI ..   I "was" not going to use AGM for the start battery.  
>> I was going to use cheaper non-serviceable Lead Acid since 
>> the Balmar DDC 12/24 allows you to configure for any kind you 
>> want.  It only charges the Start Battery when needed and 
>> pulls the charge from the house bank source.  (Assuming I do 
>> things the way I plan).
>> 
>> While writing this...I just found an AGM at 800 CCA for the 
>> same price so I may change my mind on AGM start battery.
>>  Anybody know the minimum/ideally sized start battery for the Yanmar?
>> 
> 
> 
> From the manual... 12V 64 AH or more (type 95D31L or equivalent)
> 
> I seem to recollect reading somewhere else that 650 CCA was recommended and
> looking up 95D31l batteries on the net, they seem to come in around the 650 -
> 750 CCA mark so an 800 CCA battery should be fine.
> 
> Regards,
> 
> Stephen Cox
> Tegwen #1141
>