Adding battery question

[fox islander]

Memorial day weekend I was forced to sail into my slip due to not enough amperage to crank over the motor, due to leaving the switch on ALL during an extended sail. A little stressful as it was obviously a very busy weekend with a lot of boat traffic...getting into the slip went OK but I'm determined to have a dedicated starter battery. I currently have the typical two "marine" wet cells. I found a nicely done schematic over at the international C-30 site. My question is this. If I have the two relatively new wet cell batts (which will be parralled into one bank)...should the new starter motor be wet cell also, or is it OK to add an AGM for the starter batt? I was thinking an AGM might be preferable as its location (next to the water heater) would be open to the motor.
My charger is a west marine WC-20 Smart charger.

thanks...

Steve
S/V Sonrisa
1990 C-30 MkII

 

[Stu Jackson]

Sure, why not, backups are good

All battery charging regimens including AGMs are shown on the bottom off the page in the table on PDF page 9 here: http://www.balmar.net/PDF/2005-mc-612-manual.pdf PRG 4 for AGMs is very similar to PRG 6 for standard flooded lead acid (regular) batteries. This is a very handy battery charging resource, as are many installation manuals.

Not knowing how you're charging doesn't help me help you, but this link should help you.

What's the link to the wiring diagram/schematic on the C30 'site?

 

[fox islander]

adding starter batt. schemetic

Stu,
...it was this one:

http://www.catalina30.com/TechLib/BatteryCircuits/DC Power Diagram new.pdf

...and thanks for the Balmar link.

-s

 

[Stu Jackson]

Links for you to read

The downside of this wiring is the "giveaway" where the output of the 1-2-B switch goes to "Starter, alternator, etc.", indicating a lack of understanding of what's there.

Lots of us have modified it by having the 1-2-B switch output go to only the starter and wire the alternator output directly to the house bank and then use whatever means you like to get the reserve bank what little charging it may need from the alternator with a manual switch or an echo charger.

See these for some other discussions:

http://forums.catalina.sailboatowners.com/showthread.php?p=601215

http://forums.sbo.sailboatowners.com/showthread.php?t=102027

http://forums.catalina.sailboatowners.com/showthread.php?p=520854

http://forums.catalina.sailboatowners.com/showthread.php?t=107413

http://c34.org/bbs/index.php/topic,4949.msg30101.html#msg30101

 

[Bad Obsession]

I have modified the battery set-up in my MKII Catalina 30. I moved the spare battery from the battery compartment to the area underneath the quarter berth. I got a group 24 starting battery that is sealed from West Marine. I fiberglassed a battery platform in that location and the red battery cable from the battery position in the original battery box into the quarter berth.

Once that was done and the new battery was mounted, I placed two group 27 batteries in my battery compartment that are deep cycle. Those batteries are wired in parallel so that the red battery cable labeled for Battery #2 on the switch to the hot post of one of the batteries. I took a new red battery cable of the same size and ran that from the second battery hot post to the post of the first group 27 battery that is wired to the switch of Battery #2. I then took the ground cable (black Cable) and ran it from the battery box off the post of the first battery 2 to the negative side of the post of the second battery in battery 2. I then ran a cable from there to the aux. battery (battery #1).

I usually start off of battery position #2. The first battery is auxilary and I rarely use it.

I also added a Xantrex Link 10 to my battery system so I know what I have left as far as amp hours, the battery percentage left, and what battery percentage I am using.

This was a very easy upgrade and well worth doing for peace of mind alone.

 

[Bob S]

BadO,

I just finished my upgrade as per Stu's recommendations. I ran the alternator directly to the house bank. I got 2 group 31's from Defender that fit perfectly in the battery compartment. Like you, I added a platform for a group 24 reserve battery under the aft birth. I went a little crazy running almost all new wiring I got from Boater's World going out of business sale. I did Mainesail's Leece Neville 90 amp alternator with a Balmar regulator, echo charger and battery monitor. I would recommend fusing everything.

 

[Bad Obsession]

Good show.

If I ever end up adding refrigeration I think that I will add a third battery into the system. I am still trying to figure out where to put this though. Maybe across the boat in that small open area behind the holding tank.

Who knows.