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

I thought that equalizing was specifically forbidden with AGM since
overcharging is one of the few things that can kill them. How do you
replace the water boiled off?

And when you say "down to 12.1 volts" what load is on it?


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

Thanks for eh quick reply, Lifeline states that you can equalize at
15.5 volts and not to open the batteries. I check the voltage with no
load after about 20 min.

wrote in message
oups.com...
Thanks for eh quick reply, Lifeline states that you can equalize at
15.5 volts and not to open the batteries. I check the voltage with no
load after about 20 min.

My Lifeline batteries do not have caps that can be removed and equilization
was strongly discouraged. At least that was the story from Concord 6 years
ago when I bought my 2 8D batteries. Using voltage to measure the state
of a battery requires the battery sit without load for 24 hours. AGM
batteries
do not behave like liquid batteries. When put under load they sag lower
than liquid batteries initially. For example, when I put a 20A load on my
fully charged bank, the voltage will drop to 12.5 or so. But it will stay
there for many hours until it knees off. Capacity of the bank is fine, just
the
voltages are lower than in a liquid bank. I've had my 2 8D Lifeline
batteries for almost 6 years under rigorous use. They still have over 90%
of their original capacity.

Doug

So I shouldn't panic when the voltage goes down to 12.0 with an average
of about a 5 amp load? I will separate the batteries tomorow when they
are down to the 12.1 and are down about 80 and charge only one and see
if the other comes up.
Thanks.

Its been a great trip, everyone should go cruising

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. 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


Steve D'Antonio wrote a neat article on just this question in the
Nov/Dec issue of Ocean Navigator. And ON has made the article
available freely on its website at
http://www.oceannavigator.com/site/c...id=8685&page=1

Cheers

Bil

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.

What kind of charge regulator do you have on your alternator? AGM's are
more sensitive to chronic over- and/or under-charging. It may be that
running your engine to charge them has destroyed your batteries.


Velvet Paws wrote:
Steve D'Antonio wrote a neat article on just this question in the
Nov/Dec issue of Ocean Navigator. And ON has made the article
available freely on its website at
http://www.oceannavigator.com/site/c...id=8685&page=1


Excellent link, thanks for posting.

One reason why I am sticking with the old fashioned flooded batteries is
that any malfunction in the electrical system gets very expensive. I can
replace flooded type Gr-31s for $65 each if something goes wrong and I
can add water to them if they get a bit overcharged from time to time.
For the price of a set of AGM batteries I can replace my battery bank 3
or 4 times over.

Fresh Breezes- Doug King

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

Not at all, but 12.0 is about as low as you want to go. If you measure
a fully charged battery you will notice it is around 12.6 rather than the
typical 12.8 for a liquid battery.

Doug

wrote in message
oups.com...
So I shouldn't panic when the voltage goes down to 12.0 with an average
of about a 5 amp load? I will separate the batteries tomorow when they
are down to the 12.1 and are down about 80 and charge only one and see
if the other comes up.
Thanks.

Its been a great trip, everyone should go cruising

Hello Doug,

The data I see suggests that if you have a 6 ampere load and
you measure 12.0 volts, the battery is at something like a
15% state of charge. (Assuming a 420 AH bank)

As I posted elsewhere, a 6 ampere load on a new, fully
charged battery bank of 420 AH should give an almost no-load
voltage reading.

Unfortunately, we don't know the state of charge (either
perceived or actual) of the original poster's bank when he
measured 12.0 volts under a 6 ampere load.

Regards,

Chuck

Doug Dotson wrote:
Not at all, but 12.0 is about as low as you want to go. If you measure
a fully charged battery you will notice it is around 12.6 rather than the
typical 12.8 for a liquid battery.

Doug

wrote in message
oups.com...

So I shouldn't panic when the voltage goes down to 12.0 with an average
of about a 5 amp load? I will separate the batteries tomorow when they
are down to the 12.1 and are down about 80 and charge only one and see
if the other comes up.
Thanks.

Its been a great trip, everyone should go cruising