[C320-list] New Batteries for Odyssey

[Troy Dunn]

Rod

I converted to GC2s.  Soooo much easier to deal with weight wise.  Here are
some other pros:

1) they are true deep cycle batteries designed to take a lot of punishment.
2) they are generally cheaper per usable amp hour per cycles delivered than
any 4D battery
3) they are generally more forgiving than an AGM if abused

Some cons

1) they are not a perfect fit..two 6V GC2s in series will be slightly
longer and slightly narrower than a single 12V 4D.
2) like all lead acid batteries they deliver significantly less usable amp
hours than the 20 hr rated capacity.   Figure for GC2s about half rated
capacity.
3) some day soon they will not be a better deal than carbon foam batteries
and then you'll be second guessing if you should have split up the problem
and put carbon foam (or maybe even Lithium Ion Phosphate) in for your house
and a cheaper FLA for your backup/reserve/start (depending on how you wire
this all up.)
4) they are not valve regulated so they must be watered.

I ended up with four GC2s for my house.  On the upper Chesapeake they have
not gone below 85% SOC on a 3 day weekend.   I've cranked the fridge.  Run
the halogens in the salon, left the deck light on until bedtime, used the
Axiom pro as an anchor alarm all night, etc.   it's a great bank for the
upper Chesapeake and your normal gunkholing activities.    I must point out
that I also installed a Balmar alternator.   When I first start the Yanmar
to leave an anchorage the batteries are asking for about 70 amps.   That
falls off rapidly after about 30 minutes (about the time it takes to leave
an anchorage, raise the sails and shut down the engine.

I will be taking a long trip in a few weeks and will have a much better
idea on how the batteries perform but I'm expecting to be very satisfied.
I have not yet even considered running the engine just to charge the
batteries.

I posted all the pictures of my power upgrades in my photo album, including
wiring diagrams.   I upgraded alternator, added smart gauge and ACR before
getting rid of the 4Ds.   If all you want to do is convert to GC2s, you can
skip all that, modify the battery tray to accommodate the slightly longer
length and add a small cable to wire each set of two 6V batteries in
parallel.   Be advised you may need to cut some holes in the compartment
covers for the battery posts.  I went the distance and dropped the shelves
enough to eliminate that problem too.

If you do go the GC2 route.  I went with US Battery 2200 XC2 They are rated
at 232 Amp-Hr at the 20 hour rate.  I found the prices at Tri State Battery
in Newark,DE to be incredibly attractive.  I think the Trojan equivalent is
slightly more expensive.  There are other golf cart batteries you can buy
at Sam's club that may not be quite as good but are actually probably the
better overall bargain when factoring in price per amp hr per cycle.   For
me...changing the batteries less often was worth a small premium, the
batteries are lighter than 4D, but...they are still a big chunk of back
breaking lead.

FWIW-

Troy Dunn
Hull #514