Charge rate up to 40%

[Ross MacKillop]

How much faster would 110a (two 55's) be over a 75?

With three 210 Ah batteries half discharged

2 hours 47 minutes--- generator run time with 100 AMP charger or
4 hours 10 minutes-- generator run time with 75 amp charger.

100 amp Overkill? No By this article maximum charger could higher.-- from
boatus ttp://www.boatus.com/boattech/battchg.htm

If you own a small boat and
you only need battery power at dockside intermittently for things like
lights and bilge pumps, an SCR (silicone-controlled rectifier)
charger may work best for you. It varies its charge to keep your battery
at a constant 13.4 volts. The ones we carry are fully automatic and have
multiple charging capabilities.


Live-aboards and larger boats with many 12-volt accessories usually
have ferro-resonant chargers that put out 12 volts continuously
to keep up with constant power demands. Ours are fully automatic,
self-regulating,
and ruggedly built to give many years of dependable service.


Experts agree that the best way to replace the energy you consume from
your boat's batteries is through a controlled, multi-stage process.
Both conventional lead-acid (flooded) batteries and gel cells will
charge
faster and last longer if they are charged in distinct phases that
take
into account their chemical and physical complexities. The recommended
three-stage charging process works as follows:

1.
Bulk Stage: This first stage provides a constant amperage bulk charge
of 25-40% of the battery's capacity (in amp hours, Ah) up to about
14.4
volts (14.2 for gel cells). This bulk charge will restore about 75%
of the battery's total capacity. It takes less time than tapering
chargers,
like ferro-resonant and SCR chargers, because the smart charger
delivers
greater current to the batteries which can accept greater current
loads
when they are discharged.

2.
Absorption Stage: The remaining 25% of capacity is restored at a
decreasing rate. Maintaining the battery at 14.4 volts (14.2 for gel),
the amperage is steadily reduced. The battery is considered fully
charged
when it will accept only 2-4% of its amp-hour capacity at 14.4 volts.

3.
Float Phase: The charge amperage has declined to 2-4% of the battery's
capacity, and voltage drops to 13.5 (13.8 for gel cells). This
maintains
the battery without losing electrolyte from gassing.

4.
Equalization: Applies to lead-acid batteries only. This fourth,
manually triggered stage prevents lead-acid batteries from aging
prematurely
by applying a small, constant current until the battery reaches 16
volts,
which dissolves the hardened lead sulfate crystals on the battery
plates
and prolongs battery life.






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http://www.flickr.com/gift/

[Don Bradner]

In general it is true that bigger is better. With 3-stage chargers, though, you
do not get 33% faster full charge with 100 amps than you do with 75 amps

That is because, after the initial bulk charge has brought the voltage up to
14.x volts the amps start to drop. Once the output of the 100-amp charger has
dropped to 75 amps the time advantage has been exhausted, and the remainder of
the charge will take the same amount of time with each charger.

My charger puts out 105 amps peak. When my 660AH of batteries are around 50%
depleted it runs at that 105 amps for about 1 hour before reaching peak voltage
and beginning to drop. At that point it still has over 200AH left to put into
the batteries, and will take several hours to get there. Real-world says that
100 amps would do it in about 5 hours, and 75 amps in about 6 hours.

Because of that, when boondocking, I don't run the generator to anywhere near
full charge most of the time. Once the charge rate drops off to between 60 and
80 amps I turn the generator off.

This is not the best thing for the batteries, and shortens their life by some
percentage, but when you figure the cost of running a 15KW generator just to put
30-40 amps into the batteries to top them off I figure to save enough on fuel to
make the loss of battery life (which will still be many years with AGMs)
reasonable.

With my method, having more amps of charging is a good thing. I wouldn't mind
having 200 amps of charge, but you have to realize if you do that it will finish
bulk really quickly and rapidly drop off from there.

On 2/22/2008 at 8:20 PM Ross MacKillop wrote:

>How much faster would 110a (two 55's) be over a 75?
>
>With three 210 Ah batteries half discharged
>
>2 hours 47 minutes--- generator run time with 100 AMP charger or
>4 hours 10 minutes-- generator run time with 75 amp charger.
>
>100 amp Overkill? No By this article maximum charger could higher.-- from
>boatus ttp://www.boatus.com/boattech/battchg.htm
>
>If you own a small boat and
> you only need battery power at dockside intermittently for things
>like
> lights and bilge pumps, an SCR (silicone-controlled rectifier)
> charger may work best for you. It varies its charge to keep your
>battery
> at a constant 13.4 volts. The ones we carry are fully automatic
>and have
> multiple charging capabilities.
>
>
> Live-aboards and larger boats with many 12-volt accessories
>usually
> have ferro-resonant chargers that put out 12 volts continuously
> to keep up with constant power demands. Ours are fully
>automatic, self-regulating,
> and ruggedly built to give many years of dependable service.
>
>
> Experts agree that the best way to replace the energy you
>consume from
> your boat's batteries is through a controlled, multi-stage
>process.
> Both conventional lead-acid (flooded) batteries and gel cells
>will charge
> faster and last longer if they are charged in distinct phases
>that take
> into account their chemical and physical complexities. The
>recommended
> three-stage charging process works as follows:
>
> 1.
> Bulk Stage: This first stage provides a constant amperage bulk
>charge
> of 25-40% of the battery's capacity (in amp hours, Ah) up to
>about 14.4
> volts (14.2 for gel cells). This bulk charge will restore about
>75%
> of the battery's total capacity. It takes less time than
>tapering chargers,
> like ferro-resonant and SCR chargers, because the smart charger
>delivers
> greater current to the batteries which can accept greater
>current loads
> when they are discharged.
>
> 2.
> Absorption Stage: The remaining 25% of capacity is restored at a
> decreasing rate. Maintaining the battery at 14.4 volts (14.2 for
>gel),
> the amperage is steadily reduced. The battery is considered
>fully charged
> when it will accept only 2-4% of its amp-hour capacity at 14.4
>volts.
>
> 3.
> Float Phase: The charge amperage has declined to 2-4% of the
>battery's
> capacity, and voltage drops to 13.5 (13.8 for gel cells). This
>maintains
> the battery without losing electrolyte from gassing.
>
> 4.
> Equalization: Applies to lead-acid batteries only. This fourth,
> manually triggered stage prevents lead-acid batteries from aging
>prematurely
> by applying a small, constant current until the battery reaches
>16 volts,
> which dissolves the hardened lead sulfate crystals on the
>battery plates
> and prolongs battery life.
>
>
>
>
>
>
> Looking for the perfect gift? Give the gift of Flickr!
>
>http://www.flickr.com/gift/
>
>
>
>
>Yahoo! Groups Links
>
>
>

[Gregory OConnor]

Shure sounds like more to it. I did some simple math and got this
crude result:
*Ross 100ampCharger 2 hour 47min = 167min
167 min 100 amp = 315 ah
167 min 1 amp = 3.15 ah
1 min 1 amp = .01886 ah
53 min 1 amp = 1 ah

*Ross 75ampCharger 4 hour 10 min = 250 min
250 min 75 amp = 315 ah
250 min 1 amp = 4.2 ah
1 min 1 amp = .0168 ah
59 min 1 amp = 1 ah


Don,
Are you saying 200 amp would charge your example in in 4 1/2 hours?
your bulk charge numbers agree with Ross. maybe there is charger
technology out there that could top off the batteries quicker?? Or
it may be cause to get a honda 2000watt minigenset for balance of
charge??




--- In WanderlodgeForum@yahoogroups.com, "Don Bradner"
wrote:
>
> In general it is true that bigger is better. With 3-stage
chargers, though, you do not get 33% faster full charge with 100
amps than you do with 75 amps
>
> That is because, after the initial bulk charge has brought the
voltage up to 14.x volts the amps start to drop. Once the output of
the 100-amp charger has dropped to 75 amps the time advantage has
been exhausted, and the remainder of the charge will take the same
amount of time with each charger.
>
> My charger puts out 105 amps peak. When my 660AH of batteries are
around 50% depleted it runs at that 105 amps for about 1 hour before
reaching peak voltage and beginning to drop. At that point it still
has over 200AH left to put into the batteries, and will take several
hours to get there. Real-world says that 100 amps would do it in
about 5 hours, and 75 amps in about 6 hours.
>
> Because of that, when boondocking, I don't run the generator to
anywhere near full charge most of the time. Once the charge rate
drops off to between 60 and 80 amps I turn the generator off.
>
> This is not the best thing for the batteries, and shortens their
life by some percentage, but when you figure the cost of running a
15KW generator just to put 30-40 amps into the batteries to top them
off I figure to save enough on fuel to make the loss of battery life
(which will still be many years with AGMs) reasonable.
>
> With my method, having more amps of charging is a good thing. I
wouldn't mind having 200 amps of charge, but you have to realize if
you do that it will finish bulk really quickly and rapidly drop off
from there.
>
> On 2/22/2008 at 8:20 PM Ross MacKillop wrote:
>
> >How much faster would 110a (two 55's) be over a 75?
> >
> >With three 210 Ah batteries half discharged
> >
> >2 hours 47 minutes--- generator run time with 100 AMP charger or
> >4 hours 10 minutes-- generator run time with 75 amp charger.
> >
> >100 amp Overkill? No By this article maximum charger could
higher.-- from
> >boatus ttp://www.boatus.com/boattech/battchg.htm
> >
> >If you own a small boat and
> > you only need battery power at dockside intermittently
for things
> >like
> > lights and bilge pumps, an SCR (silicone-controlled
rectifier)
> > charger may work best for you. It varies its charge to
keep your
> >battery
> > at a constant 13.4 volts. The ones we carry are fully
automatic
> >and have
> > multiple charging capabilities.
> >
> >
> > Live-aboards and larger boats with many 12-volt
accessories
> >usually
> > have ferro-resonant chargers that put out 12 volts
continuously
> > to keep up with constant power demands. Ours are fully
> >automatic, self-regulating,
> > and ruggedly built to give many years of dependable
service.
> >
> >
> > Experts agree that the best way to replace the energy
you
> >consume from
> > your boat's batteries is through a controlled, multi-
stage
> >process.
> > Both conventional lead-acid (flooded) batteries and gel
cells
> >will charge
> > faster and last longer if they are charged in distinct
phases
> >that take
> > into account their chemical and physical complexities.
The
> >recommended
> > three-stage charging process works as follows:
> >
> > 1.
> > Bulk Stage: This first stage provides a constant
amperage bulk
> >charge
> > of 25-40% of the battery's capacity (in amp hours, Ah)
up to
> >about 14.4
> > volts (14.2 for gel cells). This bulk charge will
restore about
> >75%
> > of the battery's total capacity. It takes less time than
> >tapering chargers,
> > like ferro-resonant and SCR chargers, because the smart
charger
> >delivers
> > greater current to the batteries which can accept
greater
> >current loads
> > when they are discharged.
> >
> > 2.
> > Absorption Stage: The remaining 25% of capacity is
restored at a
> > decreasing rate. Maintaining the battery at 14.4 volts
(14.2 for
> >gel),
> > the amperage is steadily reduced. The battery is
considered
> >fully charged
> > when it will accept only 2-4% of its amp-hour capacity
at 14.4
> >volts.
> >
> > 3.
> > Float Phase: The charge amperage has declined to 2-4%
of the
> >battery's
> > capacity, and voltage drops to 13.5 (13.8 for gel
cells). This
> >maintains
> > the battery without losing electrolyte from gassing.
> >
> > 4.
> > Equalization: Applies to lead-acid batteries only. This
fourth,
> > manually triggered stage prevents lead-acid batteries
from aging
> >prematurely
> > by applying a small, constant current until the battery
reaches
> >16 volts,
> > which dissolves the hardened lead sulfate crystals on
the
> >battery plates
> > and prolongs battery life.
> >
> >
> >
> >
> >
> >
> > Looking for the perfect gift? Give the gift of Flickr!
> >
> >http://www.flickr.com/gift/
> >
> >
> >
> >
> >Yahoo! Groups Links
> >
> >
> >
>

[Don Bradner]

On 2/23/2008 at 6:43 AM Gregory OConnor wrote:

>Are you saying 200 amp would charge your example in in 4 1/2 hours?

Probably more like 3 to 3-1/2 hours. The first 100AH would flood into the
batteries in about 1/2 hour, and then the rate would start dropping, but it
would still be putting it in way faster than a 75 or 100-amp charger for quite
awhile. In the comparisons we were doing, 75 to 100 is not a huge increase. 100
to 200 is huge.

>your bulk charge numbers agree with Ross. maybe there is charger
>technology out there that could top off the batteries quicker??

I don't believe there is any way you can push juice into a battery at maximum
amps while constraining voltage. If there is, that would be fast, but it defies
the nature of a lead-acid battery.

>Or it may be cause to get a honda 2000watt minigenset for balance of
>charge??

I've certainly thought of it, and might consider it if I was a year-round
boondocker like some people I know. For us it is about 40-60 nights per year,
and not worth the aggravation.

[Troy Tikalsky]

Should the 12 volt accessories that are also using voltage during this time be considered?

Troy

----- Original Message -----

From: "bluethunder@arcatapet.com"

To: "WanderlodgeForum@yahoogroups.com"

Sent: Saturday, February 23, 2008 9:37 AM

Subject: Re: [WanderlodgeForum] Re: Charge rate up to 40%

On 2/23/2008 at 6:43 AM Gregory OConnor wrote:

>Are you saying 200 amp would charge your example in in 4 1/2 hours?

Probably more like 3 to 3-1/2 hours. The first 100AH would flood into the batteries in about 1/2 hour, and then the rate would start dropping, but it would still be putting it in way faster than a 75 or 100-amp charger for quite awhile. In the comparisons we were doing, 75 to 100 is not a huge increase. 100 to 200 is huge.

>your bulk charge numbers agree with Ross. maybe there is charger
>technology out there that could top off the batteries quicker??

I don't believe there is any way you can push juice into a battery at maximum amps while constraining voltage. If there is, that would be fast, but it defies the nature of a lead-acid battery.

>Or it may be cause to get a honda 2000watt minigenset for balance of
>charge??

I've certainly thought of it, and might consider it if I was a year-round boondocker like some people I know. For us it is about 40-60 nights per year, and not worth the aggravation.

[Don Bradner]

Yes. I have about 5 amps of drain that is continuous, so if I'm showing 105 amps
it is really 100 for charge purposes. Not many DC items beyond that drain
normally when parked except some lights at night.

Don Bradner
90 PT40 "Blue Thunder"
Posting today by satellite from Dead Horse Ranch State Park, Cottonwood, AZ

On 2/23/2008 at 12:53 PM Troy Tikalsky wrote:

>Should the 12 volt accessories that are also using voltage during this
>time be considered?
>
>Troy
>
>
> ----- Original Message -----
> From: Don Bradner
> To: WanderlodgeForum@yahoogroups.com
> Sent: Saturday, February 23, 2008 9:37 AM
> Subject: Re: [WanderlodgeForum] Re: Charge rate up to 40%
>
>
> On 2/23/2008 at 6:43 AM Gregory OConnor wrote:
>
> >Are you saying 200 amp would charge your example in in 4 1/2 hours?
>
> Probably more like 3 to 3-1/2 hours. The first 100AH would flood into
>the batteries in about 1/2 hour, and then the rate would start dropping,
>but it would still be putting it in way faster than a 75 or 100-amp
>charger for quite awhile. In the comparisons we were doing, 75 to 100 is
>not a huge increase. 100 to 200 is huge.
>
> >your bulk charge numbers agree with Ross. maybe there is charger
> >technology out there that could top off the batteries quicker??
>
> I don't believe there is any way you can push juice into a battery at
>maximum amps while constraining voltage. If there is, that would be fast,
>but it defies the nature of a lead-acid battery.
>
> >Or it may be cause to get a honda 2000watt minigenset for balance of
> >charge??
>
> I've certainly thought of it, and might consider it if I was a
>year-round boondocker like some people I know. For us it is about 40-60
>nights per year, and not worth the aggravation.

[joewalton2003]

It is my understanding that the batteries will dictate how much
amperage they draw. In other words, if your batteries are down and
they attempt to pull 150 amps from a 100 amp charger, two things will
happen. First, you will overload your charging system. Second, you
will shorten your battery life by allowing your batteries to accept a
surface charge. Deep Cycle batteries need a deep charge to retain
their capacity. There is excellent information on this subject at
David Smead's website, - amplepower.com.


Joe
91 PT40
Arizona
--- In WanderlodgeForum@yahoogroups.com, "Troy Tikalsky"
wrote:
>
> Should the 12 volt accessories that are also using voltage during
this time be considered?
>
> Troy
>
>
> ----- Original Message -----
> From: Don Bradner
> To: WanderlodgeForum@yahoogroups.com
> Sent: Saturday, February 23, 2008 9:37 AM
> Subject: Re: [WanderlodgeForum] Re: Charge rate up to 40%
>
>
> On 2/23/2008 at 6:43 AM Gregory OConnor wrote:
>
> >Are you saying 200 amp would charge your example in in 4 1/2
hours?
>
> Probably more like 3 to 3-1/2 hours. The first 100AH would flood
into the batteries in about 1/2 hour, and then the rate would start
dropping, but it would still be putting it in way faster than a 75 or
100-amp charger for quite awhile. In the comparisons we were doing,
75 to 100 is not a huge increase. 100 to 200 is huge.
>
> >your bulk charge numbers agree with Ross. maybe there is charger
> >technology out there that could top off the batteries quicker??
>
> I don't believe there is any way you can push juice into a
battery at maximum amps while constraining voltage. If there is, that
would be fast, but it defies the nature of a lead-acid battery.
>
> >Or it may be cause to get a honda 2000watt minigenset for
balance of
> >charge??
>
> I've certainly thought of it, and might consider it if I was a
year-round boondocker like some people I know. For us it is about 40-
60 nights per year, and not worth the aggravation.
>

[Don Bradner]

Batteries don't "attempt to pull" any particular charge rate. The charger
regulates the current, and internal resistance then dictates the voltage. As the
charge continues, the voltage will always rise if the current is above trickle
levels, as the resistance increases but the charger continues to put out the
amps.

It doesn't matter if your battery bank is 200AH, 400AH, or 1200AH, 75 or 100 amp
chargers are equally capable of raising the voltage to 14.x; it just takes
longer at 75 amps. The fact that a 1200AH bank can be bulk-charged at 300 amps
without harm does not mean that 75 amps will be unable to charge it, nor will 75
amps only produce a surface charge if maintained long enough (hours, in this
case) to bring the voltage all the way up.

If the charger is constant output, the batteries would eventually reach a
resistance/voltage where they would literally boil. A charger should instead
begin to reduce the current such that voltage remains constant during the
acceptance stage.

On 2/24/2008 at 1:32 AM joewalton2003 wrote:

>It is my understanding that the batteries will dictate how much
>amperage they draw. In other words, if your batteries are down and
>they attempt to pull 150 amps from a 100 amp charger, two things will
>happen. First, you will overload your charging system. Second, you
>will shorten your battery life by allowing your batteries to accept a
>surface charge. Deep Cycle batteries need a deep charge to retain
>their capacity. There is excellent information on this subject at
>David Smead's website, - amplepower.com.
>
>
>Joe
>91 PT40
>Arizona
>--- In WanderlodgeForum@yahoogroups.com, "Troy Tikalsky"
> wrote:
>>
>> Should the 12 volt accessories that are also using voltage during
>this time be considered?
>>
>> Troy
>>
>>
>> ----- Original Message -----
>> From: Don Bradner
>> To: WanderlodgeForum@yahoogroups.com
>> Sent: Saturday, February 23, 2008 9:37 AM
>> Subject: Re: [WanderlodgeForum] Re: Charge rate up to 40%
>>
>>
>> On 2/23/2008 at 6:43 AM Gregory OConnor wrote:
>>
>> >Are you saying 200 amp would charge your example in in 4 1/2
>hours?
>>
>> Probably more like 3 to 3-1/2 hours. The first 100AH would flood
>into the batteries in about 1/2 hour, and then the rate would start
>dropping, but it would still be putting it in way faster than a 75 or
>100-amp charger for quite awhile. In the comparisons we were doing,
>75 to 100 is not a huge increase. 100 to 200 is huge.
>>
>> >your bulk charge numbers agree with Ross. maybe there is charger
>> >technology out there that could top off the batteries quicker??
>>
>> I don't believe there is any way you can push juice into a
>battery at maximum amps while constraining voltage. If there is, that
>would be fast, but it defies the nature of a lead-acid battery.
>>
>> >Or it may be cause to get a honda 2000watt minigenset for
>balance of
>> >charge??
>>
>> I've certainly thought of it, and might consider it if I was a
>year-round boondocker like some people I know. For us it is about 40-
>60 nights per year, and not worth the aggravation.
>>
>
>
>
>
>
>Yahoo! Groups Links
>
>
>