Comments below:

Len wrote in message ...
I experience a very short battery-life and I want to know the cause
before I install anything new.
The fridge / freezer and other consumers constantly draw power
(between 4 and 11 amp)
I have a 3-stage 120 amp charger (bulk at 14,4,absorption at 13,6 and
float at 13,0)
My batteries are 18 months old. 6 x 180 Ah. They were called
"Maintenance-free". As I understand now that means you can't add
destilled water later on, don't see any advantage of that.
At present my battery-capacity is very low. As I look at it now I'm
confronted with replacing my batteries after 18 months.


Anyone familiar with such problems that (maybe) arise from using the
charger as a power supply during float-charging?

Do I bourdon my batteries by creating a lot of small
discarge/charge-cycles?

Any advice is welcomed for this (surely not unique?) liveaboard-
stuation with 220AC shore-power and use of 12-v appliances.

Thanks in advance, Len.

I suspect that your charger sees a lower battery voltage when you are using
it as a power supply. As a result it comes out of float and goes back to
either bulk or absorption voltage levels, boiling the electrolyte out of
your "maintenance free" batteries. Many maintenance free batteries actually
have caps that can be removed by careful prying, they come off in groups of
three. Check yours and see if your electrolyte level is way low. Adding
some distilled water to refill and then charging will get some capacity
back. Next time buy flooded batteries and "Hydrocaps" for them.
http://www.solar-electric.com/hydrocaps.html
--
Ken Heaton & Anne Tobin
Cape Breton Island, Canada
kenheaton AT ess wye dee DOT eastlink DOT ca