Boat battery question???
 

On Thu, 25 Jun 2009 16:41:55 GMT, "Lew Hodgett"
wrote:

2000/15% = 13,333 AH of battery bank is required for a 2,000 amp
charging rate.

Normal charging voltage is anywhere from 13.2VDC-13.8VDC.

Lew, I respectully disagree with both of those statements.

A recharge rate of 25% is normally acceptable for the bulk charging
phase, up to 70 or 80% of full charge.

13.2 to 13.8 is usually considered the "float" range where the battery
is being maintained at full charge.

Boat battery question???
 

"Wayne.B" wrote:

Lew, I respectully disagree with both of those statements.

A recharge rate of 25% is normally acceptable for the bulk charging
phase, up to 70 or 80% of full charge.

The operative word is "AVERAGE".

Yes, you can have 25% recharge rate for a portion of the cycle;
however, the 15% recharge rate is a design parameter given to me by a
Trojan application engineer who at the time was older than dirt, and
had forgotten more about wet cell batteries than either one of us will
ever learn.

IOW, the time to completely recharge will be Total AH/15%.

13.2 to 13.8 is usually considered the "float" range where the
battery
is being maintained at full charge.

Back in the days when I was in this business, regulators were set as
low as possible to minimize boiling.

Basic spec was 13.6 +\- 0.2.

Lew

Boat battery question???
 

On Thu, 25 Jun 2009 23:29:36 GMT, "Lew Hodgett"
wrote:

Back in the days when I was in this business, regulators were set as
low as possible to minimize boiling.

Basic spec was 13.6 +\- 0.2.

That's a good "float" voltage for a battery that doesn't get
discharged very much, like an engine starting battery. A deep cycle
battery which routinely gets disharged down to the 50% level would
take forever to recharge at 13.6 volts. That's why multi-stage
chargers have become popular on cruising boats.

Boat battery question???
 

"Wayne.B" wrote:

A deep cycle
battery which routinely gets disharged down to the 50% level would
take forever to recharge at 13.6 volts.

"Forever" is a relative term.

Just turning on the engine is beyond "forever" for me.

Basic reason I had provided for 16, T-105s and solar panels until the
money ran outG.

A L/N 4800 machine goes a long way to minimize engine time.

It will give you 120A @ 2,000 alternator RPM which BTW, is a "hot"
rating, not "cold" as most competitors offer.

Lew

Boat battery question???
 

On Thu, 25 Jun 2009 09:28:33 -0400, Wayne.B
wrote:

On Thu, 25 Jun 2009 18:50:25 +0700, Bruce In Bangkok
wrote:

Larry posted about people who had multiple 250 Amp alternators
installed. I simply asked how many volts it would take to charge a
battery bank at the installed 2,000 amps.

You seem to be saying that with 14.2 - 14.4 VDC the current flow will
be 2,000 amps, which would make the battery resistance about .00715
Ohms.

Somehow I don't think that is correct..

Actually it is because that is the voltage that *all* 12 volt lead
acid batteries get charged at. The point is, that to charge at 2,000
amps, you need to have about 8,000 amp-hours of battery capacity,
which is not very practical for a 12 volt system because of connection
and wiring losses.

You seem to be confused.

As far as the charger is concerned a battery is just a resister and
acts the same as any other resister. If you increase the voltage
output of the charger you will increase the amperage flowing through
the battery.

You also seem to have missed the point of the entire exchange between
Larry and myself which was a rather (I thought) understated bit of
sarcasm about people who seem to believe that installing massive
amounts of charging capacity is going to shorten significantly the
amount of time to charge a given sized battery bank.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Boat battery question???
 

On Thu, 25 Jun 2009 10:58:42 -0500, cavelamb
wrote:

Bruce In Bangkok wrote:
On Thu, 25 Jun 2009 05:08:26 -0400, Wayne.B
wrote:

On Thu, 25 Jun 2009 14:40:38 +0700, Bruce In Bangkok
wrote:

O.K., if you want to be pedantic,
How much voltage do you need to pump approximately 2000 X ( 6.242 ×
1018^18) electrons per second into a battery.
If the battery is sized properly, 14.2 volts will get the job done,
maybe 14.4 for the first 70 or 80% if you're in a hurry.


Larry posted about people who had multiple 250 Amp alternators
installed. I simply asked how many volts it would take to charge a
battery bank at the installed 2,000 amps.

You seem to be saying that with 14.2 - 14.4 VDC the current flow will
be 2,000 amps, which would make the battery resistance about .00715
Ohms.

Somehow I don't think that is correct..

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Hey Bruce,

Your math is correct.

The problem is that the internal resistance of a healthy battery is a lot higher
than that (which would limit current).

I know....
Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Boat battery question???
 

On Fri, 26 Jun 2009 00:28:39 GMT, "Lew Hodgett"
wrote:


"Wayne.B" wrote:

A deep cycle
battery which routinely gets disharged down to the 50% level would
take forever to recharge at 13.6 volts.

"Forever" is a relative term.

Just turning on the engine is beyond "forever" for me.

Basic reason I had provided for 16, T-105s and solar panels until the
money ran outG.

A L/N 4800 machine goes a long way to minimize engine time.

It will give you 120A @ 2,000 alternator RPM which BTW, is a "hot"
rating, not "cold" as most competitors offer.

I have a pair of these guys rated at 250 amps and running with dual
belts:

http://www.alternatorparts.com/Extreme%20Duty%20Dual%20Rectifier%20CS-144%20type.htm

They are performing very well so far and are much less expensive than
L/Ns.

Boat battery question???
 

"Wayne.B" wrote:

I have a pair of these guys rated at 250 amps and running with dual
belts:

http://www.alternatorparts.com/Extreme%20Duty%20Dual%20Rectifier%20CS-144%20type.htm

They are performing very well so far and are much less expensive
than
L/Ns.

Did they include an output curve?

High output at low RPM isn't Low cost.

Neither is a "hot" rating.

Lew

Boat battery question???
 

On Fri, 26 Jun 2009 01:46:44 GMT, "Lew Hodgett"
wrote:

Did they include an output curve?

High output at low RPM isn't Low cost.

Neither is a "hot" rating.

They do OK on both counts based on my observations. They're mounted
on DD6-71 diesels with about a 3 to 1 sheave diameter ratio. They
start producing full output at around 1200 engine RPMs which would be
3600 alternator RPM. I have not run any long term stress tests at
high temps but have measured them with an IR gun at about 170F while
producing 200 amps. I've only got about 50 hours on them at this
point so long term durability is still a question mark. At $450 I
can afford to carry around a spare however. They are also relatively
cheap/easy to rebuild.

Boat battery question???
 

"Wayne.B" wrote:

They do OK on both counts based on my observations. They're
mounted
on DD6-71 diesels with about a 3 to 1 sheave diameter ratio. They
start producing full output at around 1200 engine RPMs which would
be
3600 alternator RPM.

I would expect a high output alternator to produce about 80% of
nameplate at 2,000 alternator RPM and full output at no more than
3,000 RPM.

Based on your description above doubt they would meet those output
points.

Got any idea of output at 1200-1400 engine RPM?

What is top end of the DD6-71?

Difficult to tell from limited pics on web site, but it appears you
have a small case design, but that is just a guess.

Small case design offers the designer more challenges than larger
cases.

It's mostly a thermal problem.

I have not run any long term stress tests at
high temps but have measured them with an IR gun at about 170F while
producing 200 amps. I've only got about 50 hours on them at this
point so long term durability is still a question mark. At $450 I
can afford to carry around a spare however. They are also
relatively
cheap/easy to rebuild.

$450 seems a bit high, but then I haven't looked at a price for a few
years.

Lew

Boat battery question???
 

On Fri, 26 Jun 2009 04:06:40 GMT, "Lew Hodgett"
wrote:

What is top end of the DD6-71?

Difficult to tell from limited pics on web site, but it appears you
have a small case design, but that is just a guess.

They will top out at 2400 RPM but we never push them beyond 1800 for
any length of time, and more typically cruise at 1400 to 1500.

They are based on the Delco CS-144 which is considered large case in
the automotive world, but they are not a J-180 mount which is a big
plus for me. My engines are set up for a 2 inch Delco foot except
that they have a 1/2 inch mounting bolt instead of 3/8ths. Drilling
out the alternator foot to 1/2 inch is easy and there is plenty of
metal left over.

Boat battery question???
 

On Fri, 26 Jun 2009 06:25:30 -0400, Wayne.B
wrote:

y engines are set up for a 2 inch Delco foot except
that they have a 1/2 inch mounting bolt instead of 3/8ths. Drilling
out the alternator foot to 1/2 inch is easy and there is plenty of
metal left over.

That's interesting. I wonder why 3/8 isn't enough. I had a 4250 pound
airplane with the wings each held on by a couple of 1/4-20 bolts.
Loaded in double shear. [Beech D-17S].

Casady

Boat battery question???
 

Richard Casady wrote:
On Fri, 26 Jun 2009 06:25:30 -0400, Wayne.B
wrote:

y engines are set up for a 2 inch Delco foot except
that they have a 1/2 inch mounting bolt instead of 3/8ths. Drilling
out the alternator foot to 1/2 inch is easy and there is plenty of
metal left over.

That's interesting. I wonder why 3/8 isn't enough. I had a 4250 pound
airplane with the wings each held on by a couple of 1/4-20 bolts.
Loaded in double shear. [Beech D-17S].

Casady


No, Richard.

You might want to remeasure...

Boat battery question???
 

On Fri, 26 Jun 2009 09:38:57 -0500, Richard Casady
wrote:

On Fri, 26 Jun 2009 06:25:30 -0400, Wayne.B
wrote:

y engines are set up for a 2 inch Delco foot except
that they have a 1/2 inch mounting bolt instead of 3/8ths. Drilling
out the alternator foot to 1/2 inch is easy and there is plenty of
metal left over.

That's interesting. I wonder why 3/8 isn't enough. I had a 4250 pound
airplane with the wings each held on by a couple of 1/4-20 bolts.
Loaded in double shear. [Beech D-17S].


Everything about a DD6-71 is industrial strength overkill. They were
designed originally to power Sherman tanks. My main generator is
powered by a Yanmar industrial diesel and it is built like a toy in
comparison.

Boat battery question???
 

On Fri, 26 Jun 2009 10:25:58 -0500, cavelamb
wrote:

Richard Casady wrote:
On Fri, 26 Jun 2009 06:25:30 -0400, Wayne.B
wrote:

y engines are set up for a 2 inch Delco foot except
that they have a 1/2 inch mounting bolt instead of 3/8ths. Drilling
out the alternator foot to 1/2 inch is easy and there is plenty of
metal left over.

That's interesting. I wonder why 3/8 isn't enough. I had a 4250 pound
airplane with the wings each held on by a couple of 1/4-20 bolts.
Loaded in double shear. [Beech D-17S].

Casady


No, Richard.

You might want to remeasure...

I disassembled the thing, I ought to know. 1/4 inch bolts.

Casady

Boat battery question???
 

On Sat, 20 Jun 2009 18:00:46 -0400, jeff wrote:

Tuuk wrote:
Hi

I bought the two Nautaulis deep cycle big batteries for 139. ea. Also the
motomaster 10/2 amp automatic charger regurlarily 70.

I have had the 2amp charger on one of the batteries for about 6 hours or 8
hours and little bubbling going on I can hear and the charger still is not
changing from red light (charging) to green light (charged).

Should I keep it on the 2am for longer? Batteries are only 1 week old from
Canadian Tire and charger is also new.


random thoughts:

Its hard to say about the bubbling because a small amount of bubbling is
expected, but a large amount means possible overcharging. As others
say, get a simple Voltmeter and a cheap specific gravity tester - you
can get both for under $10. And of course make sure the battery has the
proper amount of distilled water.

Your batteries hold a bit over 100 Amp-hours, meaning that if the were
totally dead it would take over 50 hours for your 2 Amp charger to get
one close to full. The last 10% could take some hours more. However,
they should have be delivered with at least a 50% charge - otherwise
you'd have a case to return them as DOA, since taking them below 50%
diminishes the lifetime. Look for a manufacturing code to make sure it
hasn't sat on the dealer's shelf for 6 months or more.

That said, I would expect the batteries to need a significant initial
charge (unless the dealer claimed they were fully charged) so the 2 Amp
mode really will take overnight or more to get it up to full. Or you
could use the 10 Amp mode to do it faster. BTW, I regularly charge at a
rate double that (scaled for my larger bank) but my charger is well
controlled so it doesn't apply too high a Voltage. In fact, the
purpose of a deep cycle battery is to be able to take them down to about
50%, and then recharge them reasonably quickly, and repeat this about
500 times. If you really want to charge at a slow rate, this is the
device to get:
http://www.amazon.com/Battery-Tender...dp/B00068XCQU/




You would have a hard time seriously overcharging a 100 amp hour
flooded deep cycle battery using a 2 amp trickle charger.

Being a new battery, it probably has never been fully and properly
charged. Battery charging is more complicated than merely stuffing
electricity back into the battery. The last 5-10% of capacity is the
hardest to achieve.

Boat battery question???
 

On Sun, 28 Jun 2009 11:37:39 -0400, wrote:



Being a new battery, it probably has never been fully and properly
charged. Battery charging is more complicated than merely stuffing
electricity back into the battery. The last 5-10% of capacity is the
hardest to achieve.

Seems that getting batteries with 5-10% more capacity than you need,
and not worrying about the last 5-10% would be a solution.
I suspect that is too easy, aside from psychology, and somebody will
explain why.
I do know that I always find something in the last place I look for it
though. No doubts there.

--Vic

Boat battery question???
 

On Sun, 28 Jun 2009 10:53:27 -0500, Vic Smith
wrote:

On Sun, 28 Jun 2009 11:37:39 -0400, wrote:



Being a new battery, it probably has never been fully and properly
charged. Battery charging is more complicated than merely stuffing
electricity back into the battery. The last 5-10% of capacity is the
hardest to achieve.

Seems that getting batteries with 5-10% more capacity than you need,
and not worrying about the last 5-10% would be a solution.

Batteries are never quite big enough. I think there is a tendency to
add things that draw power., or simply get more casual about useage,
as your battery banks and charging system expand.

I changed over to AGM batteries for a number of reasons, but one was
lower internal resistance, which makes for faster and easier charging.
That effectively increased my capacity without adding any weight.


I suspect that is too easy, aside from psychology, and somebody will
explain why.
I do know that I always find something in the last place I look for it
though. No doubts there.

--Vic

Boat battery question???
 

On Sun, 28 Jun 2009 12:32:26 -0400, wrote:

Batteries are never quite big enough. I think there is a tendency to
add things that draw power., or simply get more casual about useage,
as your battery banks and charging system expand.

Additionally, batteries gradually lose capacity as they age, combined
with the fact that you really shouldn't draw them down more than 50%.
In reality you can only use about 30 to 40% of rated capacity without
unduly shortening battery life.

Boat battery question???
 

On Sun, 28 Jun 2009 15:18:49 -0400, Wayne.B
wrote:

On Sun, 28 Jun 2009 12:32:26 -0400, wrote:

Batteries are never quite big enough. I think there is a tendency to
add things that draw power., or simply get more casual about useage,
as your battery banks and charging system expand.

Additionally, batteries gradually lose capacity as they age, combined
with the fact that you really shouldn't draw them down more than 50%.
In reality you can only use about 30 to 40% of rated capacity without
unduly shortening battery life.

Electrical buget is much easier if you just omit refrigeration, and
pay attention to everything else. Don't run anything unless you really
need to run it. You don't need your whole boat's interior lit up
bright enough to read by. Well thought out ventilation means you
almost never need to run even a small fan. I rarely run my batteries
down anywhere near 50%.

I enjoy that my boat's environment is very different from my land
bound home. I'm pretty conservative with energy there, too, but not to
the same degree. I did reduce my heating oil usage 27% this past
winter by adding a few hundred dollars worth of insulation in
strategic places. That will continue to save every year going forward.
I'm looking into geothermal for the primary house. Looks like about
20-30k, but part of that is absorbed by what it would cost me to
replace my present boiler when it's due in a few years, so it's not
really so bad. There are also usually all sorts of credits and tax
advantages available. I could probably even put up enough PV panels
(with a battery bank) to cover power for the geothermal's pumps and
controls. For me, it's not just about saving the money. I like the
idea of using less energy, even if there is no big savings. There are
savings, though. It just requires longer term thinking than many are
capable of.