One or 2 groups of Batteries??
 

Do you consider it better to have one or 2 sets of house batteries?

From the material I have read and some practical experience one seems
to be a better answer with a separate battery for the starter or as
the dock side house battery.

I think Nigel Calder goes with the one set of batteries for the house?

http://www.amplepower.com/primer/prefer/index.html

" The Preferred System

The Preferred System consists of a single house bank, and a dedicated
starter battery for all engines. A separate generator battery is
sometimes present. "

"......a two house bank system is no longer necessary. In fact, the
more battery banks in use, the less reliable the system will be, while
also increasing cost and management problems."

"Instead of a 1-2-both switch, a simple parallel switch can be used to
start the engine from the house bank if needed. "

"But, if you make the house bank from parallel batteries a cell
failure in one only knocks out that battery."

"There are other positive benefits of a single house bank versus two."
"...a gain in effective capacity results because the rate of discharge
relative to battery capacity is reduced."


FYI
http://www.amplepower.com/wire/dual_alt/index.html

Dual Alternator Controller

Installation and Operating Instructions

Ample Power Models DAC-12 and DAC-24 August 16, 2005

INCLUDING DIAGRAM

XXXXXXXXXXXX

http://www.amplepower.com/wire/next/nextp.html

Next step reg. DIAGRAM

One big house bank and a separate starting battery is best for a number
o reasons.

Doug
s/v Callista

"Mic" wrote in message
...
Do you consider it better to have one or 2 sets of house batteries?

From the material I have read and some practical experience one seems
to be a better answer with a separate battery for the starter or as
the dock side house battery.

I think Nigel Calder goes with the one set of batteries for the house?

http://www.amplepower.com/primer/prefer/index.html

" The Preferred System

The Preferred System consists of a single house bank, and a dedicated
starter battery for all engines. A separate generator battery is
sometimes present. "

"......a two house bank system is no longer necessary. In fact, the
more battery banks in use, the less reliable the system will be, while
also increasing cost and management problems."

"Instead of a 1-2-both switch, a simple parallel switch can be used to
start the engine from the house bank if needed. "

"But, if you make the house bank from parallel batteries a cell
failure in one only knocks out that battery."

"There are other positive benefits of a single house bank versus two."
"...a gain in effective capacity results because the rate of discharge
relative to battery capacity is reduced."


FYI
http://www.amplepower.com/wire/dual_alt/index.html

Dual Alternator Controller

Installation and Operating Instructions

Ample Power Models DAC-12 and DAC-24 August 16, 2005

INCLUDING DIAGRAM

XXXXXXXXXXXX

http://www.amplepower.com/wire/next/nextp.html

Next step reg. DIAGRAM

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote:

One big house bank and a separate starting battery is best for a number
o reasons.

We have two house banks, and no starting battery. I think there are
advantages each way.

With two house banks, we can be sure that we won't use up all the
battery capacity overnight, and will have plenty of power to start the
engine up in the morning. Since most of our battery use is NOT for
starting the engine, it doesn't make any sense to have the type of
battery which is basically only good for that type of use. It is
unused most of the time, and is basically wasted power. And won't the
charging system have to be different for just the one battery, than
for the house bank?

We do have a large number of batteries - each bank is eight 6 volt
batteries. I think it would be hard to find enough space for that
many batteries in one place without putting them into the living
space.

Bob converted a car to run on electricity and ran it to work for 5
years - in the car he had 16 or 18 six volt batteries plus a 12 volt
battery for the lights and radio.


"Mic" wrote in message
...
Do you consider it better to have one or 2 sets of house batteries?

From the material I have read and some practical experience one seems
to be a better answer with a separate battery for the starter or as
the dock side house battery.

I think Nigel Calder goes with the one set of batteries for the house?

http://www.amplepower.com/primer/prefer/index.html

" The Preferred System

The Preferred System consists of a single house bank, and a dedicated
starter battery for all engines. A separate generator battery is
sometimes present. "

"......a two house bank system is no longer necessary. In fact, the
more battery banks in use, the less reliable the system will be, while
also increasing cost and management problems."

"Instead of a 1-2-both switch, a simple parallel switch can be used to
start the engine from the house bank if needed. "

"But, if you make the house bank from parallel batteries a cell
failure in one only knocks out that battery."

"There are other positive benefits of a single house bank versus two."
"...a gain in effective capacity results because the rate of discharge
relative to battery capacity is reduced."


FYI
http://www.amplepower.com/wire/dual_alt/index.html

Dual Alternator Controller

Installation and Operating Instructions

Ample Power Models DAC-12 and DAC-24 August 16, 2005

INCLUDING DIAGRAM

XXXXXXXXXXXX

http://www.amplepower.com/wire/next/nextp.html

Next step reg. DIAGRAM


grandma Rosalie

(Mic) wrote in :


" The Preferred System

The Preferred System consists of a single house bank, and a dedicated
starter battery for all engines. A separate generator battery is
sometimes present. "

I disagree....

"......a two house bank system is no longer necessary. In fact, the
more battery banks in use, the less reliable the system will be, while
also increasing cost and management problems."

Ol' Nigel, the expert just because he has a publisher, must have a pretty
large boat. If he does, then he can have one huge house battery. But,
real boaters don't have that luxury. The batteries go where they can. One
house bank means a 130AH deepcycle or two 230AH golf cart batteries in
series because there's just no place to put them. This isn't enough power
if you have radio/radar/autopilot/refridgerator/pumps/computer and lights
running 24/7 at sea. Then, what happens if a cell shorts or opens or just
decays? Is ol Nigel gonna run it off the starting battery? I think NOT.
He's gonna sit in the dark while we go on with our redundant system of TWO
house battery banks, only concerned with a little conservation.

NASA has at least two, if not 4 to 8, of everything aboard any spacecraft.
A ship is a spacecraft...stranded in its environment with no hope of
repairs...it still needs redundancy. Even two sets of 130AH deep cycles,
which now require no maintenance, is better than one set of golf cart
batteries, which do. Nobody in a boat has too much power...especially sail

"Instead of a 1-2-both switch, a simple parallel switch can be used to
start the engine from the house bank if needed. "

Unless, of course, your NOT at the dock out there in the 8' waves where you
can't work to disconnect the shorted starting battery being beaten to death
by the sea. I use a simple paralleling switch in my stepvan because if I
have to I can stop, get out, and fix whatever's wrong. A 33' sloop in 8'
seas doesn't have that luxury, what with everyone hanging on for dear life
rockin' and rollin' just trying to keep her pointed home. A simple switch
paralleling the two banks on a shorted starting battery will simply short
the whole house. It isn't going to start.


"But, if you make the house bank from parallel batteries a cell
failure in one only knocks out that battery."

See? He answers my problem in the paragraph above. This is why Lionheart
has TWO 1-2-Both battery switches. One switch selects which house battery
powers the house. The other battery switch selects whether the house or
the starting battery starts the Perkins. If you put both switches in BOTH,
they all crank the Perkins and power the house. REDUNDANCY...always
REDUNDANCY.

I like redundant charging, too. The Perkins has TWO alternators, 80A for
the starting battery on the original engine mount and 120A on the house
batteries connected to a diode separator that charges both banks. If one
alternator fails, simply put both switches in BOTH and either one of the
alternators charges all the batteries at once. Power is our FRIEND.


"There are other positive benefits of a single house bank versus two."
"...a gain in effective capacity results because the rate of discharge
relative to battery capacity is reduced."

Nope...doesn't wash.....

The ampere-hour rating of any battery, even his, depends on the LOAD
current on that battery. The lighter the load, the higher the actual amp-
hour capacity of the battery. Put a 1A light bulb across a 130AH deepcycle
and time how long it takes it to die.....MUCH longer than 130 hours. 130AH
is the 20 amp load rating. Draw 50A off it and it's dead in minutes, not
hours, because the chemical reaction of acid and lead can only happen so
fast.

When one has two battery banks, the load current is halved on them. The
real amp-hour rating at this load goes up significantly as the results.
Nigel has it backwards!


FYI
http://www.amplepower.com/wire/dual_alt/index.html

Dual Alternator Controller

REDUNDANCY....always REDUNDANCY. This controller fails you gots NO
CHARGING! Two SIMPLE regulators reduces your total failure probablility to
near zero.

I like integrated regulators....GASP!...WHAT?!!....Integrated regulators?!
How can this be?!

The integrated, internal regulators in all your cars works just fine. When
was the last time you lost a REGULATOR when your car's alternator went out?
You didn't. You lost a brush or a more probably a rectifier diode. The
internal regulator reduces the wiring maze in the engine room, another
point of failure. The internal regulator is made for THAT alternator, not
a whole series of alternators like these gee-whiz expensive beasts with
their LED lights, plugs that corrode, etc. What is this fascination with
ever-increasing the complexity of such a simple device? Regulators are
VERY accurately controlled by Zener diodes in 2005. They've been that way
for decades. You don't need to be screwing around with "settings" on
regulators. Put 14-14.5V to the house battery and he's one happy camper!

The other thing I don't like, but Lionheart has already, is these BIG
alternators. Ever look at a battery charger? Do you charge it at 120
amps? No? Why? Battery charging chemistry is S-L-O-W! Time is your
charging battery's friend. The longer you take to charge it, the more
charge it absorbs and the safer it is for it....especially DEEP CYCLE house
batteries. Starting batteries, like your car battery, made of lots more
plates with huge surface areas to create huge currents for seconds can
charge at much higher rates than a deep cycle with its low count, thick
plates with much lower surface area. The charging current per square inch
of plate surface is the same, it's just that the deep cycle has lots LESS
surface area on thicker plates. This charging them for an hour at 100A is
absurd! The chemistry just can't absorb the current you're shoving in
there fast enough, so it rids itself of excess by getting HOT. Heat
generated at high charging rates DOESN'T charge it. You end up with a gas
station surface charge, which doesn't last. Golf cart 230AH batteries LOVE
about 25-30A of charge. They hardly get warm and the specific gravity goes
all the way up to 1.260 without percolating them. So, why do we need an
alternator bigger than 30A + the house load current while we're charging?
We don't.


Ample power......two banks of L-16s at 1.260 gravity....ahh...ample power.

--
Larry

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
:

One big house bank and a separate starting battery is best for a number
o reasons.



Any idea why?

--
Larry

On Sat, 20 Aug 2005 08:38:41 -0400, Larry wrote:

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
:

One big house bank and a separate starting battery is best for a number
o reasons.



Any idea why?

http://www.vonwentzel.net/Battery/03.Banks/index.html

"Some things to keep in mind:

The only caveat to large banks of batteries is proper internal fusing.
If a cell shorts out in a battery, the battery voltage will drop
approximately 2 Volts. All batteries in the bank will start
discharging into the shorted battery, unless fuses take the bad
battery out of the circuit. Thus, battery banks need to be fused
internally as well as externally."

--
Larry

"Rosalie B." wrote in message
...
"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote:

One big house bank and a separate starting battery is best for a number
o reasons.

We have two house banks, and no starting battery. I think there are
advantages each way.

Not really.

With two house banks, we can be sure that we won't use up all the
battery capacity overnight, and will have plenty of power to start the
engine up in the morning.

Same with 1 hourse and one starting battery.

Since most of our battery use is NOT for
starting the engine, it doesn't make any sense to have the type of
battery which is basically only good for that type of use.

Yes it is since a house bank is deep cycle which is different than a
starting battery.
Using a deep cycle battery to start an engine is hard on the battery and if
for
some reason the engine is being hard to start, it may not provide enough
current
and will further damagage the bank.

It is
unused most of the time, and is basically wasted power.

Not wasted. Is your EPIRB wasted money? It is guaranteed to be
there when it is needed no matter how forgetful the operator is. The battery
is small and cheap. Mine is 1300 CCA and cost about $70.

And won't the
charging system have to be different for just the one battery, than
for the house bank?

Different, but not complex. A parallelling solenoid is the simplest solution
and
something like The Eliminator or Echo Charge is the optimal solution.


We do have a large number of batteries - each bank is eight 6 volt
batteries. I think it would be hard to find enough space for that
many batteries in one place without putting them into the living
space.

Lost you here. Another point is one large unified house bank will have a
longer
total lifetime that two separate banks. I have a set of 2 8D gels that are
over
12 years old and still doing fine in almost everyday use. The boat has two
8D
AGM that have onlt barely started to loose capacity and are 6 years old.

Bob converted a car to run on electricity and ran it to work for 5
years - in the car he had 16 or 18 six volt batteries plus a 12 volt
battery for the lights and radio.

That's only because the lights and radio needed 12V and the driver motors
run at a higher voltage. Different situation.

Doug
s/v Callista


"Mic" wrote in message
...
Do you consider it better to have one or 2 sets of house batteries?

From the material I have read and some practical experience one seems
to be a better answer with a separate battery for the starter or as
the dock side house battery.

I think Nigel Calder goes with the one set of batteries for the house?

http://www.amplepower.com/primer/prefer/index.html

" The Preferred System

The Preferred System consists of a single house bank, and a dedicated
starter battery for all engines. A separate generator battery is
sometimes present. "

"......a two house bank system is no longer necessary. In fact, the
more battery banks in use, the less reliable the system will be, while
also increasing cost and management problems."

"Instead of a 1-2-both switch, a simple parallel switch can be used to
start the engine from the house bank if needed. "

"But, if you make the house bank from parallel batteries a cell
failure in one only knocks out that battery."

"There are other positive benefits of a single house bank versus two."
"...a gain in effective capacity results because the rate of discharge
relative to battery capacity is reduced."


FYI
http://www.amplepower.com/wire/dual_alt/index.html

Dual Alternator Controller

Installation and Operating Instructions

Ample Power Models DAC-12 and DAC-24 August 16, 2005

INCLUDING DIAGRAM

XXXXXXXXXXXX

http://www.amplepower.com/wire/next/nextp.html

Next step reg. DIAGRAM


grandma Rosalie

"Mic" wrote in message
...
On Sat, 20 Aug 2005 08:38:41 -0400, Larry wrote:

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
:

One big house bank and a separate starting battery is best for a number
o reasons.



Any idea why?

http://www.vonwentzel.net/Battery/03.Banks/index.html

"Some things to keep in mind:

The only caveat to large banks of batteries is proper internal fusing.
If a cell shorts out in a battery, the battery voltage will drop
approximately 2 Volts. All batteries in the bank will start
discharging into the shorted battery, unless fuses take the bad
battery out of the circuit. Thus, battery banks need to be fused
internally as well as externally."

--
Larry

Good point, but a fuse will not neccessarirly mitigate a failure of this
sort.

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote:
"Rosalie B." wrote in message
.. .
"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote:

One big house bank and a separate starting battery is best for a number
o reasons.

We have two house banks, and no starting battery. I think there are
advantages each way.

Not really.

Well you have said what you prefer, and I have said what Bob prefers.
Are you saying that Bob has no logical reason for using two house
banks? If so, that is very annoying and rude of you. If not, then
you need to work on being more tactful.

With two house banks, we can be sure that we won't use up all the
battery capacity overnight, and will have plenty of power to start the
engine up in the morning.

Same with 1 hourse and one starting battery.

Not really.

Since most of our battery use is NOT for
starting the engine, it doesn't make any sense to have the type of
battery which is basically only good for that type of use.

Yes it is since a house bank is deep cycle which is different than a
starting battery.
Using a deep cycle battery to start an engine is hard on the battery and if
for
some reason the engine is being hard to start, it may not provide enough
current
and will further damagage the bank.

It is
unused most of the time, and is basically wasted power.

Not wasted. Is your EPIRB wasted money? It is guaranteed to be
there when it is needed no matter how forgetful the operator is. The battery
is small and cheap. Mine is 1300 CCA and cost about $70.

This is irrelevant. You might just as well say that the battery
operated searchlight is wasted money because we might never need it.
Or indeed any battery operated item. Doesn't have a thing to do with
starting batteries or house batteries.

And won't the
charging system have to be different for just the one battery, than
for the house bank?

Different, but not complex. A parallelling solenoid is the simplest solution
and
something like The Eliminator or Echo Charge is the optimal solution.


We do have a large number of batteries - each bank is eight 6 volt
batteries. I think it would be hard to find enough space for that
many batteries in one place without putting them into the living
space.

Lost you here. Another point is one large unified house bank will have a
longer
total lifetime that two separate banks. I have a set of 2 8D gels that are
over
12 years old and still doing fine in almost everyday use. The boat has two
8D
AGM that have onlt barely started to loose capacity and are 6 years old.

We have had 8D wet cell batteries which came with the boat in 1998 as
the original house bank, and we replaced them with golf cart batteries
last year. When we bought her, the boat didn't have a second bank
or a starting battery IIRC.

Bob considered the cost and life span of the various types of
batteries, and decided that the life span of the new techie batteries
was not long enough to make up for the extra expense and trickier
charging problems. He figured he could replace the pack of wet cell
or golf cart 3 or 4 times for the cost of one battery pack of the more
'advanced' batteries, which would at best last twice as long. He
doesn't mind watering the batteries and checking on them occasionally.

Bob converted a car to run on electricity and ran it to work for 5
years - in the car he had 16 or 18 six volt batteries plus a 12 volt
battery for the lights and radio.

That's only because the lights and radio needed 12V and the driver motors
run at a higher voltage. Different situation.

Yes I know. But he researched the batteries for the car, and he used
golf cart batteries for that too. The whole car conversion cost less
than $5,000.00, including buying the car to convert.

Doug
s/v Callista


"Mic" wrote in message
...
Do you consider it better to have one or 2 sets of house batteries?

From the material I have read and some practical experience one seems
to be a better answer with a separate battery for the starter or as
the dock side house battery.

I think Nigel Calder goes with the one set of batteries for the house?

http://www.amplepower.com/primer/prefer/index.html

" The Preferred System

The Preferred System consists of a single house bank, and a dedicated
starter battery for all engines. A separate generator battery is
sometimes present. "

"......a two house bank system is no longer necessary. In fact, the
more battery banks in use, the less reliable the system will be, while
also increasing cost and management problems."

"Instead of a 1-2-both switch, a simple parallel switch can be used to
start the engine from the house bank if needed. "

"But, if you make the house bank from parallel batteries a cell
failure in one only knocks out that battery."

"There are other positive benefits of a single house bank versus two."
"...a gain in effective capacity results because the rate of discharge
relative to battery capacity is reduced."


grandma Rosalie

On Sat, 20 Aug 2005 15:59:29 GMT, Rosalie B.
wrote:

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote:
"Rosalie B." wrote in message
. ..
"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote:

One big house bank and a separate starting battery is best for a number
o reasons.

We have two house banks, and no starting battery. I think there are
advantages each way.

Not really.


Have a look at these links:
http://www.vonwentzel.net/Battery/04.Costs/index.html

Comparing Life-Cycle Costs By Battery Technology

Excellent graphics chart

http://www.vonwentzel.net/Battery/05.Model/index.html

How the Model Calculates Life-Cycle Costs

Again an excellent resource with detailed charting


http://www.vonwentzel.net/Battery/

Comparing Marine Battery Technologies
(Gel, Absorbed Glass Mat (AGM), Flooded Lead Acid, and Nickel-Cadmium)

http://www.vonwentzel.net/Battery/00...ary/index.html

How Lead Acid Batteries Work

http://www.vonwentzel.net/Battery/01.Type/index.html

Battery Types: Flooded versus AGM and Gel
On the kinds of batteries we may use on board:

http://www.uuhome.de/william.darden/

The ultimate on Battery INFO\

http://www.uuhome.de/william.darden/batbrand.htm

BATTERY MANUFACTURERS AND BRAND NAMES LIST

HUGE list

http://www.uuhome.de/william.darden/batlinks.htm
BATTERY INFORMATION LINKS LIST
Index:

Alternators

Cable, Connectors and Wiring Products

Chargers

Converters (AC to DC) and DC Power Supplies

Converters (DC to DC)

Desulfators and Pulse Chargers

Float Chargers and Battery Maintainers

Generators and Gensets

Inverters, Inverter-Chargers and Converters, (DC to AC)

Isolators, Combiners and Seperators

Jump Starters and Jumper (or Booster) Cables

Low Voltage Disconnects

Miscellaneous Battery Information

Regulators and Charge Controllers

Solar and Photovoltaic (PV)

"Smart" Chargers

Switches

Test and Monitor Equipment

http://www.uuhome.de/william.darden/batlinks2.htm

HUGE list

BATTERY REFERENCES LINK LIST

Larry wrote:
....

There's no way I know of to keep the shorted cell from exploding,
distributing its acid over everthing in every drawer in the boat....what a
mess.

My batteries are on the bridge deck in the cockpit, with a heavy
fiberglass cover. Reaching the cabin or bilge would require going
through a major bulkhead.

Of course, I wouldn't want to be sitting on the cover at the time ...

We do have a large number of batteries - each bank is eight 6 volt
batteries. I think it would be hard to find enough space for that
many batteries in one place without putting them into the living
space.


My gosh!

That is a bunch of batteries.

it would be helpful to know what you are useing them all for.

For what i used on my ancient ChisCraft 28 ft'r. was a normal 800CCA
battery for the one engine, and an 8-D "Cat" battery for the cabin. i
used a battery isolator which splits the two systems. so your cabin
battery never runs down your start battery. but when engine is running
both sets are charged. pretty simple and effective.

however it's probably obvious that my demands are far different from
yours.


Tim

On Sat, 20 Aug 2005 16:12:46 -0400, Larry wrote:

(Mic) wrote in :

The only caveat to large banks of batteries is proper internal fusing.
If a cell shorts out in a battery, the battery voltage will drop
approximately 2 Volts. All batteries in the bank will start
discharging into the shorted battery, unless fuses take the bad
battery out of the circuit. Thus, battery banks need to be fused
internally as well as externally."


If a cell shorts out in a battery, the cell explodes boiling its
electrolyte into steam, damn near instantly, unless it's already dead. The
other cells in SERIES with the dead cell have no current through it. The
other batteries may explode if not properly fused, even if the other good
cells in the blown battery oppose them, overcharging like mad in the
process. All batteries MUST BE FUSED! I like about 150% of the starter
current and the wiring must be able to handle that current level to blow
the fuse....not the crap house wiring I see on house batteries all the
time.

There's no way I know of to keep the shorted cell from exploding,
distributing its acid over everthing in every drawer in the boat....what a
mess.

I had a cell in one of two parallelled 4D batteries develop a short,
without exploding, or any other serious consequences.

I noticed while cruising that I was unable to get my batteries above
13 volts or so, despite using a 40 amp charger for 24 hours - but I
was still able to start the engine and run all accessories.

After the cruise, I was checking battery water, and found that one
battery required lots of water in all but one cell, while the other
didn't need any. Switching to the thirsty battery only, I was unable
to start the engine, and the voltage on that battery was only 10 volts
or so, while the other was over 12.

I expect that the "shorted" cell was really a low resistance, rather
than a zero-ohm short.

I've since replaced the 4Ds with 4 Golf Carts as a house bank, and a
Group 27 for starting. I don't have fuses on the two series pairs of
GCs, but do have a 1-both-2 switch so I can easily test each series
pair independently.

A problem I see with fusing sections of a battery bank is selecting a
fuse rating high enough that it won't blow when starting, or running
the bow thruster, but low enough that it will blow on a fault.



--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

"Rosalie B." wrote in message
...
"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote:
"Rosalie B." wrote in message
. ..
"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote:

One big house bank and a separate starting battery is best for a number
o reasons.

We have two house banks, and no starting battery. I think there are
advantages each way.

Not really.

Well you have said what you prefer,

What else would I have contributed.

and I have said what Bob prefers.

What do you prefer?

Are you saying that Bob has no logical reason for using two house
banks?

Yes.

If so, that is very annoying and rude of you. If not, then
you need to work on being more tactful.

No I don't You need to get into the 21st century..

With two house banks, we can be sure that we won't use up all the
battery capacity overnight, and will have plenty of power to start the
engine up in the morning.

Same with 1 hourse and one starting battery.

Not really.

Since most of our battery use is NOT for
starting the engine, it doesn't make any sense to have the type of
battery which is basically only good for that type of use.

Yes it is since a house bank is deep cycle which is different than a
starting battery.
Using a deep cycle battery to start an engine is hard on the battery and
if
for
some reason the engine is being hard to start, it may not provide enough
current
and will further damagage the bank.

It is
unused most of the time, and is basically wasted power.

Not wasted. Is your EPIRB wasted money? It is guaranteed to be
there when it is needed no matter how forgetful the operator is. The
battery
is small and cheap. Mine is 1300 CCA and cost about $70.

This is irrelevant. You might just as well say that the battery
operated searchlight is wasted money because we might never need it.
Or indeed any battery operated item. Doesn't have a thing to do with
starting batteries or house batteries.

And won't the
charging system have to be different for just the one battery, than
for the house bank?

Different, but not complex. A parallelling solenoid is the simplest
solution
and
something like The Eliminator or Echo Charge is the optimal solution.


We do have a large number of batteries - each bank is eight 6 volt
batteries. I think it would be hard to find enough space for that
many batteries in one place without putting them into the living
space.

Lost you here. Another point is one large unified house bank will have a
longer
total lifetime that two separate banks. I have a set of 2 8D gels that are
over
12 years old and still doing fine in almost everyday use. The boat has two
8D
AGM that have onlt barely started to loose capacity and are 6 years old.

We have had 8D wet cell batteries which came with the boat in 1998 as
the original house bank, and we replaced them with golf cart batteries
last year. When we bought her, the boat didn't have a second bank
or a starting battery IIRC.

Bob considered the cost and life span of the various types of
batteries, and decided that the life span of the new techie batteries
was not long enough to make up for the extra expense and trickier
charging problems. He figured he could replace the pack of wet cell
or golf cart 3 or 4 times for the cost of one battery pack of the more
'advanced' batteries, which would at best last twice as long. He
doesn't mind watering the batteries and checking on them occasionally.

Bob is wrong. The "techie" batteries are only about double the cost of
wet batteries and last more than twice the lifetime. Nothing "tricky" about
the charging, just set the charger to the right settings.

Bob converted a car to run on electricity and ran it to work for 5
years - in the car he had 16 or 18 six volt batteries plus a 12 volt
battery for the lights and radio.

That's only because the lights and radio needed 12V and the driver motors
run at a higher voltage. Different situation.

Yes I know. But he researched the batteries for the car, and he used
golf cart batteries for that too. The whole car conversion cost less
than $5,000.00, including buying the car to convert.

Golfcart batteries are very good. Higher energy density for the cost. But
none
of this has much to do with 1 house bank vs 2.

Doug
s/v Callista


"Mic" wrote in message
...
Do you consider it better to have one or 2 sets of house batteries?

From the material I have read and some practical experience one seems
to be a better answer with a separate battery for the starter or as
the dock side house battery.

I think Nigel Calder goes with the one set of batteries for the house?

http://www.amplepower.com/primer/prefer/index.html

" The Preferred System

The Preferred System consists of a single house bank, and a dedicated
starter battery for all engines. A separate generator battery is
sometimes present. "

"......a two house bank system is no longer necessary. In fact, the
more battery banks in use, the less reliable the system will be, while
also increasing cost and management problems."

"Instead of a 1-2-both switch, a simple parallel switch can be used to
start the engine from the house bank if needed. "

"But, if you make the house bank from parallel batteries a cell
failure in one only knocks out that battery."

"There are other positive benefits of a single house bank versus two."
"...a gain in effective capacity results because the rate of discharge
relative to battery capacity is reduced."


grandma Rosalie

"Tim" wrote in message
oups.com...
We do have a large number of batteries - each bank is eight 6 volt
batteries. I think it would be hard to find enough space for that
many batteries in one place without putting them into the living
space.


My gosh!

That is a bunch of batteries.

it would be helpful to know what you are useing them all for.

For what i used on my ancient ChisCraft 28 ft'r. was a normal 800CCA
battery for the one engine, and an 8-D "Cat" battery for the cabin. i
used a battery isolator which splits the two systems. so your cabin
battery never runs down your start battery. but when engine is running
both sets are charged. pretty simple and effective.

however it's probably obvious that my demands are far different from
yours.

I think we are talking about cruising sailboats here.


Tim

"Larry" wrote in message
...
(Mic) wrote in :

The only caveat to large banks of batteries is proper internal fusing.
If a cell shorts out in a battery, the battery voltage will drop
approximately 2 Volts. All batteries in the bank will start
discharging into the shorted battery, unless fuses take the bad
battery out of the circuit. Thus, battery banks need to be fused
internally as well as externally."


If a cell shorts out in a battery, the cell explodes boiling its
electrolyte into steam, damn near instantly, unless it's already dead.
The
other cells in SERIES with the dead cell have no current through it. The
other batteries may explode if not properly fused, even if the other good
cells in the blown battery oppose them, overcharging like mad in the
process. All batteries MUST BE FUSED!

Nobody sugggested that fusing isn;t necessary. Just that is does not
necessarily protect against a shorted cell. I had a cell short once and
all it did was lower the voltage of the battery and discharge the parallel
battery. No dramatic event, just dead batteries.

I like about 150% of the starter
current and the wiring must be able to handle that current level to blow
the fuse....not the crap house wiring I see on house batteries all the
time.

There's no way I know of to keep the shorted cell from exploding,
distributing its acid over everthing in every drawer in the boat....what a
mess.



--
Larry

"Tim" wrote:

We do have a large number of batteries - each bank is eight 6 volt
batteries. I think it would be hard to find enough space for that
many batteries in one place without putting them into the living
space.

My gosh!

That is a bunch of batteries.

it would be helpful to know what you are useing them all for.

We have a CSY 44. The refrigeration is either engine driven or shore
power, and is not on the 12V system. We have 4 solar panels and a
wind generator to charge the batteries, although if we are on the hook
or a mooring, we run the engine twice a day for 35-40 minutes for the
refrigeration.

Otherwise, everything is on the 12v system.

We really don't have a lot of things that other people have that
require power. We don't have a power windlass. We don't have A/C.
We don't have a microwave. We have a propane stove, and no heater,
except that if it gets cold (below 45 deg F) we will go into a marina
and plug into shore power to run a little electric space heater.

We do have 2 Lectrasan toilets, a DirecTV dish with a Follow Me
antenna, and two TVs and two DirecTV receivers. We have a LCD radar,
an autopilot, and I run the computers most of the time. We have 12V
reading lights. Bob has a whole bunch of tools, and some of them are
12V power tools and some he runs off an inverter (like the sewing
machine).

I sometimes plug the phones in to charge them. We have a SSB and two
VHF radios (one of which is on most of the time we are on the boat),
plus a couple of AM/FM radio/CD players and one or two little fans.
We have a pressure water system. And of course running lights etc.

For what i used on my ancient ChisCraft 28 ft'r. was a normal 800CCA
battery for the one engine, and an 8-D "Cat" battery for the cabin. i
used a battery isolator which splits the two systems. so your cabin
battery never runs down your start battery. but when engine is running
both sets are charged. pretty simple and effective.

however it's probably obvious that my demands are far different from
yours.


Tim

grandma Rosalie

Jeff wrote in :

Reaching the cabin or bilge would require going
through a major bulkhead.

If it's not GAS TIGHT where all the holes in its bulkheads go through with
the wires, it'll get in the cabin. Seal up all the cables to prevent it.
Proper stuffing tubes would be nice, instead of a little dab of RTV.

--
Larry

Peter Bennett wrote in
news.com:

I expect that the "shorted" cell was really a low resistance, rather
than a zero-ohm short.


It wasn't a shorted cell. It was a "dead cell". That cell had converted
lead and acid into lead sulphate crystals, so had a low gravity situation,
causing the ongoing charging problem because its voltage wouldn't come up.
These cells have quite low resistance, that's true. Lead sulphate is a
good conductor dissolved in water. What's missing is the acid. The other
cells simply forced current through the bad cell, attempting to charge it
backwards in the process, as you used it. It won't explode.

A normal battery cell that develops a short, where the plates actually
touch, is different from a dead cell. A thousand amps boils the
electrolyte as the acid-lead chemical reaction goes crazy. Acid steam
results and blows the cell, and the case, apart. Other cells may become
shorted from the impending distortion of the shorted cell pressing them
from the middle of the battery case. It isn't pretty....but it's quick!

--
Larry

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
:

Nobody sugggested that fusing isn;t necessary. Just that is does not
necessarily protect against a shorted cell. I had a cell short once
and all it did was lower the voltage of the battery and discharge the
parallel battery. No dramatic event, just dead batteries.


If you had measured the voltage across the internal straps on the "shorted
cell", I doubt you would have found it to be zero, like a shorted cell must
be. You'd have found a "dead cell", one whos acid and lead had been
converted into lead sulphate crystals that can't be charged.

Big difference.

--
Larry

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
:

Subject: One or 2 groups of Batteries??
From: "Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom
Newsgroups: rec.boats.cruising


"Rosalie B." wrote in message
...


Sorry, Rosalie. He's quite wound up this morning...(C;

--
Larry

"Larry" wrote in message
...
"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
:

Nobody sugggested that fusing isn;t necessary. Just that is does not
necessarily protect against a shorted cell. I had a cell short once
and all it did was lower the voltage of the battery and discharge the
parallel battery. No dramatic event, just dead batteries.


If you had measured the voltage across the internal straps on the "shorted
cell", I doubt you would have found it to be zero, like a shorted cell
must
be. You'd have found a "dead cell", one whos acid and lead had been
converted into lead sulphate crystals that can't be charged.

Big difference.

--
Larry

How would I go about measuring the voltage across the internal straps?

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
:

How would I go about measuring the voltage across the internal straps?


Put the meter probes down into the cell hole and press them into two
adjacent plate ends. They're flat. You'll be measuring the voltage across
the one cell your holing.

Don't forget to wash off the meter probes in clean water with your hands
after you're done. Submarine batteries are easier...individual cells...but
I wouldn't want to be 150' down when there was a short...6,250AH cells.

The battery shop at the Charleston Naval Shipyard rebuilt diesel sub
batteries when I was a young sailor. They'd take an overhead crane and
pick up the plates out of the rubber case by its big terminals. After it
drained for a while, they'd lay the plates on a regular wooden pallet. A
steel bar, probably 2" in diameter was placed across both terminals to
short the plates. That bar would glow red hot for hours on a cell with NO
ELECTROLYTE, running on the acid left in the separators. I was always
fascinated in that shop and learned a lot about battery maintenance and
repair from the experts that had done it for years. In the charging
theatre, the cells were set in lines with aisles between so each cell could
be constantly monitored and tested. Huge conductors were attached to each
cell from overhead. Standing above it all was the operator's control room,
looking over the babies on the floor. The "charger" was another BUILDING
with huge, open-faced generators powered by the shipyard's steam plant
system. Each cell was "cycled" 3 times to soften the plates before it was
charged for the "load test" it had to pass before being loaded back on
railroad cars back to the subs for replacement. Huge load banks with
monstrous fans carried off the energy discharged from the cells. There was
enough heat coming out of the building to heat all the homes in the city
all winter...just vented outside. Acid was recycled but used to be just
dumped into the river way back. Even small batteries the Navy owned (er,
ah, and some lucky sailors' batteries) could be easily repaired, bad cells
replaced then the whole thing brought up and standarized like new. There
was one under the rear seat of my 1967 Volkswagen Campmobile (Kombi) that
took up the whole compartment. It was a Greyhound bus battery that was
restored at the battery shop by some friends. The poor VW never charged
under 20A. The shop converted it from a diesel starting battery to an
850AH long-life deep cycle. Starting the little 57hp VW engine didn't even
dim the headlights!...(c; I used to camp with it where there was no power,
leaving the drop lights in my campsite on all night, all weekend. Fans,
TV, we had it all...(c;

--
Larry

In article ,
(Mic) wrote:

Do you consider it better to have one or 2 sets of house batteries?

snip

http://www.amplepower.com/primer/prefer/index.html

" The Preferred System

The Preferred System consists of a single house bank, and a dedicated
starter battery for all engines. A separate generator battery is
sometimes present. "

We have two banks for much the same reasons as Rosalie, but for our
moderate needs that are now mostly handled by solar, I'm tending towards
a smallish battery directly connected to the alternator with a
paralleling switch if I need to charge the house.

That would make it impossible to fry the alternator by switching the
wrong way by accident. In addition, I could shorten the primary battery
cables considerably, making it more likely that we'll start under all
conditions. The only downside is if the starting battery dies, but since
it won't usually have any but starting loads, it'll last a longer; I've
had original-equipment car batteries last a dozen years.


--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/