I think the deal with charging them to 100% is bull. We have had ours for 5+
years
and during a year of cruising only charged them to 80% on a regular basis.
Only charged
them to 100% on the rare occation we pulled into a marina. They are still
performing
fine. I've never equilized them since back when I got mine the concept of
equalizing
a sealed battery was unheard of. My charger doesn;t even support equilizing
an
AGM. After 5+ years they are performing about as well as they were when they
are new.

Doug

wrote in message
oups.com...
Thanks for the info, I have a Zantrex smart charger and have monitored
it closely as we have been living on the boat since last Aug, I set it
for AGM batteries and when I got it and have the 60 amp charger with
the internal voltage regulator removed. It charges at 50 amps for about
40 min then starts dropping down as the voltage rises. I have most
consistently charging from a -80 to about -20 daily. This has met
our demands and keeps the motor running down to about an hour. To go to
full charge or till the green light flashes on the Link 10 batteries
monitor would take another hour. Fully charged is about 12.7V. When we
are moving I usually run the motor for several hours and correct for
any miscalculation in the monitor. I thought this was reasonable from
the literature I had red and from the sales person of the batteries. I
then found the batteries operation manual on line and saw that they
recommended that the batteries be fully charged each time they are
charged. This is unreasonable for a cruiser and I wish I new that
before I purchased them. They only reason I went with the sealed
batteries is that I don't have an adequate vented batteries box. The
gel cells were working fine in the boat, but they were 12 years old and
swelling on the sides. We are cruising for a year and I didn't want
problems, which I am having. I now see everyone and his brother with
wet cells mounted inside the older boats and vent them into the cabin.
The literature did recommend that I equalize them at 15.5 Volts
for 5 hours. I did that and noticed some improvement. I am thinking
that they are sulfated and wonder if I can get more life back in them
by doing it again. I am worried about doing more damage though.
I will read the article, and again, thanks to everyone for you
opinions.

John

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
:

Under load the AGMs sag more than flooded batteries but then
level out and exhibit proper capacity.


Makes sense. The AGMs can't replace the acid-now-turned-to-lead-sulphate
with fresh acid like the wetcell with its convective electrolyte currents,
constantly refreshing the acid touching the surface of the plates.

I rechecked my voltage settings and they are right where the
manufactuer recommends. I have both the Xantrex truecharger for shore
power as well as the smart charger for the alternator. So I do not
think I have burned them up, but keeping then between -80 and sometimes
-100, then charging up to -20 on a 420 amp hour system seemed
resonable. From the ressearch I have done and other crusiers, it seems
like the older ones held up better then the new ones. I hve seen
several articles complaining about their performance, in ON and this
month in Latitude 38. I do remember that once we started living on the
hook last Oct the voltage would be at 12.2 with -80. But was told not
to worry about it because it could be measuring lower voltage from
having a load. So I didn't and this morning it is at 12.2 with onle -45
amp hours, after being fully charged to a standing voltage of 12.7
yesterday. It doesn't seem to go to the 12.85 like the starting battery
of the same vintage and type does.
I didn't like the ON article that was posted, it doesn't address
what crusiers should do to make them perform. If I would have seen the
article before I purchased them I would have never done so. The article
stated that the flodded type have the same problems as AGMs with
sulfation on the plates. But dosent follow up that equilizing is a
common method of maintaining the floded type, but the manufacturer only
recently recommends it on the Lifeline AGMs. If you follow the article,
the batteries should be sold with a big warning lable and a good set of
instructions. I was told that they were bullet proof, could take abuse
and all the amp hours you can through at them. The article makes it
sound like if you are .1 volt off and don't fully recharge, you are
tosting the batteries. That was not what was sold to me.
If any one has experence in bringing them back to life I would love
it. I want to leave from Cabo to Hawaii in three weeks and am
contimplating diching them and putting in flodded before I go, but what
a waste. I will contact Lifeline and see if tehy have any support in
Mexico, unlikly.

Thanks for all the suggestions.
John
S/V Pangea

wrote in
ups.com:

The article
stated that the flodded type have the same problems as AGMs with
sulfation on the plates. But dosent follow up that equilizing is a
common method of maintaining the floded type, but the manufacturer only
recently recommends it on the Lifeline AGMs. If you follow the article,
the batteries should be sold with a big warning lable and a good set of
instructions. I was told that they were bullet proof, could take abuse
and all the amp hours you can through at them. The article makes it
sound like if you are .1 volt off and don't fully recharge, you are
tosting the batteries. That was not what was sold to me.


Price is not an indication of quality in all things. Look inside one.
Very thin (they have to wrap them around a post you know)lead plates
separated by a gauze like mat soaked in sulphuric acid that, once used up
in an area, cannot MOVE like a LIQUID electrolyte can to cool the plates
with convection and mix with the rest of the electrolyte in the cell. All
this reminds one of gelcells with the jelly acid that doesn't move either
and when it "shrinks" away from the plate, that place is dead as there is
no contact.

Bulletproof it's not.

I'm concerned about the heat insulating qualities of this glass mat. We
use fiberglass to insulate our homes. How hot does this rolled up battery
get INSIDE when it is charged or discharged? How can you cool something
efficiently rolled up so tightly? At what temperature does the glass mat
and little rolled up plates warp? boil into steam? God the red starting
AGM in my stepvan just melted when one cell shorted out!

Let's ask some embarrassing questions about "sulphation". Lead is turned
into lead sulphate to make free electrons. As long as the lead sulphate
doesn't get too concentrated, it stays in solution in the electrolyte so we
can force it to revert back to sulphuric acid and elemental lead at the
surface of the plates. That's how it works, right? If we kill it too
dead, lead sulphate crystals form on the plates, insulating the lead plates
from the electrolyte. The cell is "dead" because the sulphuric acid is
used up, converted into lead sulphate crystals and we can't recover it
because the electrolyte now becomes almost an insulator, distilled water.

In a wetcell, lead sulphate crystals can and do fall off the lead plates,
exposing more lead as the crystals fall to the space at the bottom of the
container under the plates made just for this purpose. Life goes on, the
cell now has less "capacity" to charge because there is less acid in the
cell to use up as it discharges.

How do lead sulphate crystals precipitate out of a rolled up, acid soaked
guaze battery where nothing can move? Nothing can move anywhere in the AGM
(or gelcell) battery all squeezed inside that cylinder case, can it? I
can't adjust the specific gravity to make up for some of the acid loss
because it's all sealed. Balancing the cells adjusting acid concentrations
is impossible. What you get, you get.

No thanks. I think AGM batteries were invented to simplify battery
manufacture and the marketing mongers saw a great opportunity to create
market hype of a "new" and "extraordinary" new product we can sell at
exhorbitant profits. I'll keep my temperature-compensated hydrometer and
little distilled water filler monitoring what is really going on in the
cells.

Running my ham station is a set of "Edison Cells" given to me by a friend
who used to be a Holiday Inn innkeeper back in the 1960's. These cells use
Nickel and Iron for plates, making them an environmental disaster of nickel
pollution if you dump them, which you never need to do. The electrolyte is
potassium hydroxide, a base, not an acid. The date on the cells reads
1947, except on one cell that reads 1949. Nickel-Iron batteries last
virtually forever, of course making them a target to get rid of them by
battery manufacturers. These cells ran an old Holiday Inn telephone
exchange that required a live operator running a plugboard manually. The
cells are near 2V each. I have 7 in series charging them with a modified
simple SCR charger since the 1970s. Fork lift trucks used to all be
nickel-iron batteries you just charged and put distilled water into as it
is used up.

Too bad we can't put Ni-Fe batteries in a boat and replace them every 80
years or so....(c; Those are great batteries!

I found a website "expert" who says they are awful. I disagree:

"NiFe (Nickel Iron)

Energy storage density = 55 watts per kilogram
Alkaline-type electric cells using potassium hydroxide as the electrolyte
and anodes of steel wool substrate with active iron material and cathodes
of nickel plated steel wool substrate with active nickel material. This is
the original "Edison Cell". Very long life.

...."Our experience with customers using alkaline batteries in stand alone
AE systems suggests that they may have as many drawbacks as advantages when
compared to lead-acid type batteries. We suggest that potential alkaline
users evaluate the economics and performance claims carefully to determine
the suitability of any battery being considered..."
Christopher Freitas Trace Engineering
Downsides:

1. Low efficiency - may be as low as 50%, typically 60-65%.
2. very high rate of self-discharge
3. high gassing/water consumption
4. high internal resistance means you can get large voltage drops across
series cells.
5. high specific weight/volume

This also means that the output voltage varies with load and charge much
more than other batteries. If you are using an inverter, the inverter needs
to be designed with these voltage swings in mind. You may not be able to
use NiFe's if your system depends on a stable voltage, for example if you
are running certain common DC appliances such as a refrigerator directly
off the batteries. Also when using NiFe's to power DC lighting, you will
notice the light intensity fluctuates. One could always use a voltage
regulator to feed those appliances that need it, but that would decrease
the efficiency even more.

Currently, it appears that the only source for new NiFe batteries is from
Hungary, and we have heard mixed reports on them. In short, we do not
recommend them unless they are nearly free. The high losses in charging and
discharging will add an extra 25-40% to the size of the solar panels you
will need for the same energy usage.
In short, despite some hype about long life and thousands of cycles, we
feel that overall these batteries are a poor choice for nearly all solar
applications."

It's a moot point as you can no longer buy them......Did I mention you can
discharge them DEAD and they charge right back up to FULL capacity for
DECADES?......Of course, this guy saying this SELLS LEAD-ACID BATTERIES!!

Hello John,

I gather from your post that the AGMs performed this way
from the outset (i.e., when they were new).

New AGMs at 50% state of charge should measure something
like 12.5 volts.

A new, fully-charged AGM bank of 420 AH under a 5 ampere
load should see virtually no voltage drop from the 12.7 volt
nominal no-load voltage.

If the bank is 50% charged and you are drawing 60 amperes,
the voltage may drop to something like 11.7 volts under load.

As the Ocean Navigator article suggests, failure to charge
to 100% could result in degradation of performance. However,
this would not have been noticeable when the batteries were new.

Hope this info helps.

Chuck


wrote:
I have 2 4D Lifeline batteries. I bought them new last Augaust before
we left for Mexico. We have been having a great time but the batteries
are not doing nearly as well as advertised. They are in one bank of 420
amps for the house bank and I use it for everything including starting
the engine and leave another battery charged for emergency starting. We
use about 60 amps a day. I have been discharging to between 80 and 100
amps then charge back to between 20 to 40, depending on how long we
want to hear the motor running. I had thought this was a good way to
maintain the batteries. Unfortunately we are now down to about 12.1
volts after about a 60 amp discharge. I have done a 5 hour 15.5 volt
equalization and it now goes down to about 80 amps before it reaches
12.1 volts. I feel I should expect it to go down 200 amps before it
reaches 12 volts. Should I equalize again? Did I get bad batteries? or
am I doing something wrong? I have checked all connections and
separated the batteries, they don't discharge by them selves and they
go down in voltage at the same rate. Any suggestions would be helpful.
We are hoping to go to Hawaii in May from La Paz.
Thanks
John
S/V Pangea
Swan 38

On 17 Mar 2005 17:14:24 -0800, wrote:

I have 2 4D Lifeline batteries. I bought them new last Augaust before
we left for Mexico.
*snip!
I have done a 5 hour 15.5 volt
equalization and it now goes down to about 80 amps before it reaches
12.1 volts.
*snip!
Any suggestions would be helpful.
We are hoping to go to Hawaii in May from La Paz.
Thanks
John
S/V Pangea
Swan 38

John,
Over voltage or overcharging can damage AGM batteries. You need
some reliable information on AGM batteries and correct charging
procedures. I am not an expert and I have not used AGMs yet.
Try the battery manufacturer's web site or ask some place like
West Marine's support for correct charging procedure..