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.

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

Len wrote in message ...
I experience a very short battery-life and I want to know the cause
before I install anything new.

How short?


The fridge / freezer and other consumers constantly draw power
(between 4 and 11 amp)

sounds familiar.....

I have a 3-stage 120 amp charger (bulk at 14,4,absorption at 13,6 and
float at 13,0)

good.

My batteries are 18 months old. 6 x 180 Ah.

I am not familiar with a battery that is 180 amp-hours. What make/model are
these?

Is this six 12 volt batteries all in parallel?
Three sets of two 6 volt batteries?
six individual 2 volt cells?

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.

Yep. My translation of "Maintenance Free" is "Can't Maintain".

If you keep the charge and discharge rates low then the maintenance free
batteries work. They work just fine in your car. Where they typically
don't work is in a deep cycle application where the charge rates can be very
high.

On many of the maintenance free batteries you can gain access to the cells
but you have to work at it a little harder. They have a battery cap, it is
just a little harder to get off. Other batteries the caps were put on in
such a way that you will not be able to get them off without really messing
it up.


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

The type of charger you have is about the best you can get.

I suspect that you are in a different country than I am (I am in the USA) so
your choice of batteries might be a bit different. Here in the USA, the
most common use for deep cycle batteries are in Golf Carts. The standard
golf cart battery is easy to come by and fairly cheap, in fact they are
commonly found for less than an equivilant automotive battery. And they are
rugged: if you keep water in them they will last 5 years or more.

My advice is to dump the "maintenance free" batteries and go with the good
old "golf cart" batteries. In the USA, these are 6 volt batteries that are
in a case style that is referred to as T-105 or 2200. They are 10-3/8" long
by 7-1/8" wide by 10-7/8" tall, compared to the 27 series which is 12-3/4"
long by 6-3/4" wide by 9-3/4" tall. Connect two of these in series to get
12 volts. Connect as many of these sets in parallel as you need to get the
desired amp-hour capacity. One set of these batteries will provide you with
about 225 amp-hours each.

Good luck
Rod McInnis

What kind of batteries are these? I'm not sure I have
even seen a "Maintenance Free" deep cycle battery other
than gels or AGM. Maintenace Free batteries are usually
starved electrolyte type and are for starting applications.

Doug
s/v Callista

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.

"Doug Dotson" wrote in message
...
What kind of batteries are these? I'm not sure I have
even seen a "Maintenance Free" deep cycle battery other


"Delco Voyager" comes to mind. I bought several of these before I figured
out that they were crap.

Rod

Op Thu, 6 May 2004 07:19:34 -0300, schreef "Ken Heaton"
:


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


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

Everyone , thanks for your replies.
Ken, I think you hit it spot on.
Do you use the hydrocaps yourself ? Seems like the ultimate solution.

Thanks again, Len.

Op Thu, 6 May 2004 20:29:37 -0400, schreef "Doug Dotson"
:

What kind of batteries are these? I'm not sure I have
even seen a "Maintenance Free" deep cycle battery other
than gels or AGM. Maintenace Free batteries are usually
starved electrolyte type and are for starting applications.

Doug
s/v Callista


The brsand is Hoppecke.
Used in cars
I think you're right about the point their typical starting batteries.

Thanks for responding, Len.

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.


Most battery chargers will boil away water in lead acid batteries and
shorten their life when 12 volt refrigerators are left on. Over
charging is even possible with many of the expensive step chargers.
Only a charger that will hold the battery voltage in the float stage
when the refrigerator runs will prevent excessive water loss.
Examples, A Heart inverter/charger will remain in float phase when the
charger is set for 100 degree battery temperature voltages and the
refrigerator draws less than 6 amps., A 10 amp GUEST smart three step
charger with only one side used producing only 5 amps., causes minimal
water loss.
The best advice is not to use maintenance free lead acid batteries and
install a sacrificial battery for the refrigerator when at the dock. I
have one boat where the Adler Barbour has been running steady for 8
years on a old battery with the small Guest Charger. For more
information on Battery Stress from chargers click on BATTERY STRESS on
my web site http://www.kollmann-marine.com

From the author of four books on boat refrigeration

I think that a liquid lead-acid battery plus hydrocaps may be
about the same cost as a gel or AGM.

Doug
s/v CAllista

Len wrote in message ...
Op Thu, 6 May 2004 07:19:34 -0300, schreef "Ken Heaton"
:


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


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

Everyone , thanks for your replies.
Ken, I think you hit it spot on.
Do you use the hydrocaps yourself ? Seems like the ultimate solution.

Thanks again, Len.

I wish that were so, but a dozen hydrocaps is under $100. Replacing my 4 golf
cart batteries with AGMs will be about a $400 premium.



"Doug Dotson" wrote in message
...
I think that a liquid lead-acid battery plus hydrocaps may be
about the same cost as a gel or AGM.

Doug
s/v CAllista

Len wrote in message ...
Op Thu, 6 May 2004 07:19:34 -0300, schreef "Ken Heaton"
:


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


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

Everyone , thanks for your replies.
Ken, I think you hit it spot on.
Do you use the hydrocaps yourself ? Seems like the ultimate solution.

Thanks again, Len.