[C320-list] Couple of start Battery questions

[David Swanson]

   Scott,

   I installed a separate start battery and combined by house bank years
   ago.  The start battery was installed purely as a back up.

   I installed the start battery installed on a custom wood shelf mounted
   to the hull forward of the main battery bank on the starboard side of
   the boat.  I don?t recall the group number, but it was sized with
   enough CCA to be able to start the Yanmar diesel engine.  It is a West
   Marine brand maintenance free lead-acid battery.

   I have my house bank on the OEM battery switch position 1 and the start
   battery on position 2.  Consequently, I use a Xantrex Echo Charge to
   keep it charged from the main house bank.  I generally start the engine
   with the main house bank, but the start battery is there in case I draw
   down my house bank while at an extended anchorage.  I researched option
   quite a bit on Sailnet, Crusiers Forum, etc. before I embarked on this
   project.  I followed the advice in the Compass Marine website for the
   start battery and combining the house bank and upgrading the house bank
   to 6V golf cart batteries.  The Compass Marine website has solid
   advice.  Subsequently I have installed a flexible Solbian 125W solar
   panel on our bimini.  It is a great set up that allows me to be at
   anchor for weeks and still have enough power for refrigeration.

   Most all of my work can be seen at the C320IA owners website under our
   boat name.  Good luck with your project.

   Dave Swanson

   S/V Emily Ann

   2007 C320 MK II, No. 1107

   Mukilteo, Washington

   On Sun, Jan 27, 2019 at 6:49 AM Scott Westwood
   <scottwestwood at bellsouth.net> wrote:

     Decided to install start battery.
     If you have a separate start battery.....
     What size do you have?  i have heard Grp27 and Grp25?  What CCA?
     etc...??  Optima has a Grp34 that has 800CCA and is only (LxWxH): 10
     x 6 7?8 x 7 13?16 in and, according to them, is leak proof and take
     vibration for only $196??
     Next question gets more complicated.   Here is what I was thinking:
     I was going to combine my 2 batteries into single house bank.  Then
     install a Balmar DDC 12/24 Duo charge.
     I was told.... that if I connect the start battery to switch 2
     (Switch 1 would be house bank) that I could turn the switch to Pos
     2, then start the engine, then quickly turn the switch through
     "Both" to Pos1.  This would not cause any issues.
     Any thoughts on that?
     I was hoping to use the existing Pos2 wire that (I think) will reach
     my start battery if I can fit it into the space behind the Anchor
     Windlass switch.
     Thoughts?  Last thing I want to do is cause damage to expensive
     batteries or equipment.
     Thanks,
     Scott Westwood scottwestwood at bellsouth.net H (919)-362-8538    C
     (919)-618-7185