I am adding a second battery to my small cabin sailboat, as a "house"
battery. Basically, it will run one thermoelectric cooler while away from
shore power. I am NOT planning on using a battery switch. I would sure
like to add a simple schematic to my post....but since binaries are frowned
upon (and I don't have the means to draw one on the computer anyway,)
here's the plan:

Engine (40hp Suzuki) NEGATIVE to battery #1 (starting) NEGATIVE. Engine
POSITIVE to center (feed) terminal of isolator. The isolator OUTPUTS will
go to the POSITIVES of batteries #1 and #2, respectfully.

CABLE from NEGATIVE of battery #1, to NEGATIVE of battery #2.

Accessories such as stereo, VHF, the feed for cabin and navigation light
panel will be attached to battery #1 + and -.

The accessory plug for the cooler will bridge the battery #2 + and -. (the
cooler draws 6 amps....my 100 a/h gel cell runs it all night after a good
charge now.)

I am NOT too worried about using battery #2 for starting.....I have a "jump
start" battery that is always well maintained....and have never had to use
it even after an overnight with stereo playing, judicious cabin lighting
use, and burning anchor light after dark.

Any potential for unwanted power feedback with this plan?

Any suggestions would be greatly appreciated!

My thanks in advance!

Joe
s/v "South of 80"
Charlestown, MD
(PLEASE remove the obvious anti-spam text from my e-mail address if you
reply there)

JAD wrote:

I am adding a second battery to my small cabin sailboat, as a "house"
battery. Basically, it will run one thermoelectric cooler while away from
shore power. I am NOT planning on using a battery switch. I would sure
like to add a simple schematic to my post....but since binaries are frowned
upon (and I don't have the means to draw one on the computer anyway,)
here's the plan:

Engine (40hp Suzuki) NEGATIVE to battery #1 (starting) NEGATIVE. Engine
POSITIVE to center (feed) terminal of isolator. The isolator OUTPUTS will
go to the POSITIVES of batteries #1 and #2, respectfully.

CABLE from NEGATIVE of battery #1, to NEGATIVE of battery #2.

Accessories such as stereo, VHF, the feed for cabin and navigation light
panel will be attached to battery #1 + and -.

The accessory plug for the cooler will bridge the battery #2 + and -. (the
cooler draws 6 amps....my 100 a/h gel cell runs it all night after a good
charge now.)

I am NOT too worried about using battery #2 for starting.....I have a "jump
start" battery that is always well maintained....and have never had to use
it even after an overnight with stereo playing, judicious cabin lighting
use, and burning anchor light after dark.

Any potential for unwanted power feedback with this plan?

Any suggestions would be greatly appreciated!

My thanks in advance!


A third jumper battery?

with only two batteries, if you should need to use a jumper
(Why?) you will make a spark as you connect it. Aside from the
explosion and fire hazard if there are gas fumes about, you will
also charge the dead battery with the charged house one,
weakening it, so I would consider not using a jumper, but instead
a switch, disconnecting one before connecting the other, to
maximise emergency starting energy available. You might not want
to do this if the engine is running, if your suzuki has an
alternator instead of a dynamo in the flywheel, more so if you
have electronic ignition.

'Course, you can always pull the start string, eh?

Your isolator diode block will prevent your batteries from
attaining full charge as they 'contribute' a .6v or so voltage
drop in the charging circuit, unless the alternator regulator is
compensated to overcharge the battery / isolator diode
combination.

In principle, I like the solenoid charging combiner idea best, as
it is more efficient in one sense, but if a solenoid must conduct
staring current, it will be so big that it's coil might use more
power to energise it for charging than you might otherwise lose
from the diode block. This would affect fuel usage a very little,
and charging time. If the solenoid were to be connected only so
as to enable charging current in the house battery, it would use
a much smaller solenoid and coil, wasting less energy overall,
while still permitting a jumper cable to be used to start the
engine if you get tired of pulling the string. I know it's a
sequential non sequiter, but who cares?

So, my favorite plan is to hook up the one battery start circuit
as if there were no second battery used, without a blocking
diode, then add a smaller, 'smart' charge voltage sensing
solenoid that would enable charging the house battery, which
would drop out when the engine is stopped. As soon as the engine
started, the solenoid would engage, replenishing the charge taken
out of the starting battery, recharging it quickly from the house
battery, and discharging the house battery somewhat. A .1 ohm
(eg) resistor in the house battery charge / boost / recharge
circuit would prevent heavy equalisation charging if you did suck
down the start battery very far. That resistor would be in series
with the solenoid charge circuit and the direction of current
flow though it could be used to shunt it during normal charge
with an active sense circuit arrangement and another small
solenoid. It would take a little logic. That would be the most
elegant solution. There are several possible variations on this
theme, all the way up to 3000 dollar charge controllers.

You could still use a jumper cable or switching arrangement to
boost or replace the starting battery, if the other battery was
ok. If you have a third battery, I would connect it to the house
battery to increase the house system reserve, provided it was a
suitable type.

Heck, if the pull start works good, chuck all of the extra
batteries to save weight, and keep the fridge door (top opening,
right, with a block of ice in a camp drinking water bag on top of
the food?) closed, and the stereo down. If the o/b is working
right, it should start easily anyway.

Ain't nothin' like messin' with a boat?
--
Terry K - My email address is MY PROPERTY, and is protected by
copyright legislation. Permission to reproduce it is
specifically denied for mass mailing and unrequested
solicitations. Reproduction or conveyance for any unauthorised
purpose is THEFT and PLAGIARISM. Abuse is Invasion of privacy
and harassment. Abusers will be prosecuted. -This notice footer
released to public domain. Spamspoof salad by spamchock -
SofDevCo

Terry Spragg wrote:

JAD wrote:

I am adding a second battery to my small cabin sailboat, as a "house"
battery. Basically, it will run one thermoelectric cooler while away from
shore power. I am NOT planning on using a battery switch. I would sure
like to add a simple schematic to my post....but since binaries are frowned
upon (and I don't have the means to draw one on the computer anyway,)
here's the plan:

Engine (40hp Suzuki) NEGATIVE to battery #1 (starting) NEGATIVE. Engine
POSITIVE to center (feed) terminal of isolator. The isolator OUTPUTS will
go to the POSITIVES of batteries #1 and #2, respectfully.

CABLE from NEGATIVE of battery #1, to NEGATIVE of battery #2.

Accessories such as stereo, VHF, the feed for cabin and navigation light
panel will be attached to battery #1 + and -.

The accessory plug for the cooler will bridge the battery #2 + and -. (the
cooler draws 6 amps....my 100 a/h gel cell runs it all night after a good
charge now.)

I am NOT too worried about using battery #2 for starting.....I have a "jump
start" battery that is always well maintained....and have never had to use
it even after an overnight with stereo playing, judicious cabin lighting
use, and burning anchor light after dark.

Any potential for unwanted power feedback with this plan?

Any suggestions would be greatly appreciated!

My thanks in advance!


A third jumper battery?

with only two batteries, if you should need to use a jumper
(Why?) you will make a spark as you connect it. Aside from the
explosion and fire hazard if there are gas fumes about, you will
also charge the dead battery with the charged house one,
weakening it, so I would consider not using a jumper, but instead
a switch, disconnecting one before connecting the other, to
maximise emergency starting energy available. You might not want
to do this if the engine is running, if your suzuki has an
alternator instead of a [magneto -tk] in the flywheel, more so if you
have electronic ignition.

'Course, you can always pull the start string, eh?

Your isolator diode block will prevent your batteries from
attaining full charge as they 'contribute' a .6v or so voltage
drop in the charging circuit, unless the alternator regulator is
compensated to overcharge the battery / isolator diode
combination.

In principle, I like the solenoid charging combiner idea best, as
it is more efficient in one sense, but if a solenoid must conduct
staring current, it will be so big that it's coil might use more
power to energise it for charging than you might otherwise lose
from the diode block. This would affect fuel usage a very little,
and charging time. If the solenoid were to be connected only so
as to enable charging current in the house battery, it would use
a much smaller solenoid and coil, wasting less energy overall,
while still permitting a jumper cable to be used to start the
engine if you get tired of pulling the string. I know it's a
sequential non sequiter, but who cares?

So, my favorite plan is to hook up the one battery start circuit
as if there were no second battery used, without a blocking
diode, then add a smaller, 'smart' charge voltage sensing
solenoid that would enable charging the house battery, which
would drop out when the engine is stopped. As soon as the engine
started, the solenoid would engage, replenishing the charge taken
out of the starting battery, recharging it quickly from the house
battery, and discharging the house battery somewhat. A .1 ohm
(eg) resistor in the house battery charge / boost / recharge
circuit would prevent heavy equalisation charging if you did suck
down the start battery very far. That resistor would be in series
with the solenoid charge circuit and the direction of current
flow though it could be used to shunt it during normal charge
with an active sense circuit arrangement and another small
solenoid. It would take a little logic. That would be the most
elegant solution. There are several possible variations on this
theme, all the way up to 3000 dollar charge controllers.

You could still use a jumper cable or switching arrangement to
boost or replace the starting battery, if the other battery was
ok. If you have a third battery, I would connect it to the house
battery to increase the house system reserve, provided it was a
suitable type.

Heck, if the pull start works good, chuck all of the extra
batteries to save weight, and keep the fridge door (top opening,
right, with a block of ice in a camp drinking water bag on top of
the food?) closed, and the stereo down. If the o/b is working
right, it should start easily anyway.

Ain't nothin' like messin' with a boat?
--repost, my mistake -tk
--
Terry K - My email address is MY PROPERTY, and is protected by
copyright legislation. Permission to reproduce it is
specifically denied for mass mailing and unrequested
solicitations. Reproduction or conveyance for any unauthorised
purpose is THEFT and PLAGIARISM. Abuse is Invasion of privacy
and harassment. Abusers will be prosecuted. -This notice footer
released to public domain. Spamspoof salad by spamchock -
SofDevCo

"JAD" I do not think you will be satisfied with the results of
powering a thermoelectric cooler on your sailboat unless the batteries
are connected to a shore power every twelve hours. There are small
portable compressor driven refrigerators like the Engel or WAECO that
can be operated for days with the help of solar panels and an outboard
alternator.

As to the power distribution system the use of a battery isolator is
not a good idea due to the voltage loss created by the isolator of
about seven tenths of a volt. The alternator on the outboard lacks the
potential to over come any added resistances; the answer is to use a
battery combiner. Battery combiners are electronic switches that close
when a charging voltage is present and opens when the charging voltage
drops below 12.8 volts. I have two basic wiring designs for boats with
outboard motors in my new 12/24 volt boat refrigeration manual. I will
describe them but if you need the hard drawings send me you're mailing
address or Fax number.
For the first system, remove any house loads that are presently
connected to the starting battery and connect them to the house
battery: Refrigerator, Dome lights Radio, Solar Panels and battery
charger. The start battery and the house battery grounds are connected
together with a new cable, this means there is now two ground cables
connected to the one ground post of the start battery. Installing the
battery combiner is simple there are two large terminals and one
small, connect the small terminal to one of the grounds and run a
large wire from each of the large terminals to the its respective
battery positive post. You need one additional item a battery charge
indicator wired across the house battery terminals. Large cruising
boats have expensive meters that even record amp-hrs but a twenty
dollar meter like those used for trolling motors or gulf carts will
do. These meters read in full and empty or percent of charge and come
with a push to test button.

The second system has a large battery selector in parallel with the
combiner so that the house battery can be used for starting. I have
this wiring system on a pontoon party barge except there is a Adler
Barbour cold machine connected to a holding plate in a large Igloo
cooler ( Picture on the first page of web site). The pontoon is
powered by a 40 HP. Honda with an eight amp-hr alternator and two
group 27 house batteries.


If you need more information on boat refrigeration or the combined
effects of refrigeration and battery chargers check my web site

http://www.Kollmann-marine.

I do not think you will be satisfied with the results of powering a
thermoelectric cooler on your sailboat unless the batteries are
connected to a shore power every twelve hours. There are small
portable compressor driven refrigerators like the Engel or WAECO that
can be operated for days with the help of solar panels and an outboard
alternator.

As to the power distribution system the use of a battery isolator is
not a good idea due to the voltage loss created by the isolator of
about seven tenths of a volt. The alternator on the outboard lacks the
potential to over come any added resistances; the answer is to use a
battery combiner. Battery combiners are electronic switches that close
when a charging voltage is present and opens when the charging voltage
drops below 12.8 volts. I have two basic wiring designs for boats with
outboard motors in my new 12/24 volt boat refrigeration manual. I will
describe them but if you need the hard drawings send me you're mailing
address or Fax number.
For the first system, remove any house loads that are presently
connected to the starting battery and connect them to the house
battery: Refrigerator, Dome lights Radio, Solar Panels and battery
charger. The start battery and the house battery grounds are connected
together with a new cable, this means there is now two ground cables
connected to the one ground post of the start battery. Installing the
battery combiner is simple there are two large terminals and one
small, connect the small terminal to one of the grounds and run a
large wire from each of the large terminals to the its respective
battery positive post. You need one additional item a battery charge
indicator wired across the house battery terminals. Large cruising
boats have expensive meters that even record amp-hrs but a twenty
dollar meter like those used for trolling motors or gulf carts will
do. These meters read in full and empty or percent of charge and come
with a push to test button.

The second system has a large battery selector in parallel with the
combiner so that the house battery can be used for starting. I have
this wiring system on a pontoon party barge except there is a Adler
Barbour cold machine connected to a holding plate in a large Igloo
cooler ( Picture on the first page of web site). The pontoon is
powered by a 40 HP. Honda with an eight amp-hr alternator and two
group 27 house batteries.


If you need more information on boat refrigeration or the combined
effects of refrigeration and battery chargers check my web site

http://www.Kollmann-marine.

THANK YOU RICHARD!

This is indeed exactly what I was looking for.

Yandina makes a 50 amp combiner (Sold under West Marine) that looks as if it
will do. They provided a .pdf document with install instructions (on web)
that parallels your instructions. The unit is TINY, temperature protected,
has status lights for it's operation, and can be wired in a number of
simple, inexpensive ways for automatic or manual operation. I can hook my
gel/ flooded single bank charger to the house battery sans problem.

I bought the combiner directly from Yandina (Beaufort, S.C.) at a $30
savings over West Marine, by choosing a rebuilt unit with full warranty.

Sincere thanks once again!

Joe
s/v "South of 80"
Charlestown, MD

"Richard Kollmann" wrote in message
m...
I do not think you will be satisfied with the results of powering a
thermoelectric cooler on your sailboat unless the batteries are
connected to a shore power every twelve hours. There are small
portable compressor driven refrigerators like the Engel or WAECO that
can be operated for days with the help of solar panels and an outboard
alternator.

As to the power distribution system the use of a battery isolator is
not a good idea due to the voltage loss created by the isolator of
about seven tenths of a volt. The alternator on the outboard lacks the
potential to over come any added resistances; the answer is to use a
battery combiner. Battery combiners are electronic switches that close
when a charging voltage is present and opens when the charging voltage
drops below 12.8 volts. I have two basic wiring designs for boats with
outboard motors in my new 12/24 volt boat refrigeration manual. I will
describe them but if you need the hard drawings send me you're mailing
address or Fax number.
For the first system, remove any house loads that are presently
connected to the starting battery and connect them to the house
battery: Refrigerator, Dome lights Radio, Solar Panels and battery
charger. The start battery and the house battery grounds are connected
together with a new cable, this means there is now two ground cables
connected to the one ground post of the start battery. Installing the
battery combiner is simple there are two large terminals and one
small, connect the small terminal to one of the grounds and run a
large wire from each of the large terminals to the its respective
battery positive post. You need one additional item a battery charge
indicator wired across the house battery terminals. Large cruising
boats have expensive meters that even record amp-hrs but a twenty
dollar meter like those used for trolling motors or gulf carts will
do. These meters read in full and empty or percent of charge and come
with a push to test button.

The second system has a large battery selector in parallel with the
combiner so that the house battery can be used for starting. I have
this wiring system on a pontoon party barge except there is a Adler
Barbour cold machine connected to a holding plate in a large Igloo
cooler ( Picture on the first page of web site). The pontoon is
powered by a 40 HP. Honda with an eight amp-hr alternator and two
group 27 house batteries.


If you need more information on boat refrigeration or the combined
effects of refrigeration and battery chargers check my web site

http://www.Kollmann-marine.