T&T: large batteries

[Krogenguy]

I just got to jump in here - it's a slow day in the PNW or just a  
reason not to go to the boat and make up some new dock lines.

Mostly, I agree w/ Denny about the most bang for the buck.  Our  
battery bank lasted 8+ years before it was changed out and was in  
good shape at the change.  I only changed because it was a  
combination of 8Ds and GCs plus we were heading out for an extended  
trip.  For a number of years, 5+-,  we operated them as separate  
banks i.e. one bank for house and one for start.  However for the  
remaining time we ran as one large bank - worked great.

The replacement batteries are all GCs w/ three stage charging, temp  
sensors and pulsers plus I added a battery watering system.  So far  
all is well.  The pulsers - one for each bank - are 12vdc powered and  
have voltage sensing capabilities - they are not battery maintainers  
or trickle chargers - left that job to the inverter/charger.

As far as history goes, our genset battery is now 10.8 years old, has  
been floated at 13.2vdc and pulsed.  Charge acceptance before the  
pulser was installed some 7 years ago was quite low (max 13.4vdc) but  
now it is in the normal range (13.8+vdc) and spins the genset like it  
is new.  This battery is charge by the single stage alternator that  
came w/ the genset - not very sophisticated at all.  The pulser w/  
its trickle charge made the difference.

As far as stratification goes, it has been hard to detect after we  
added the pulsers.  Our normal operation is to stay on the hook for 3 
+ days which pulls the batteries down to the 50/60% range.  Charging  
at rates up to 180 amps does have a tendency to stir the electrolyte  
but perhaps not as well as an equalizing charge.  We still equalize  
the main bank but infrequently, perhaps every 6 to 8 months or longer.

So, I'm sticking w/ 13.2vdc long term float at the dock, 14.4vdc max  
charge voltage and 13.5vdc float while under way.  Nothing new here  
except for the pulsers - just good battery maintenance as recommended  
by A and others.


Tom
Aventura
KK-42 #204
krogenguy at comcast.net