Reply
 
Thread Tools Display Modes
 
Old 10-09-2012, 08:52 PM   #1
Hospitality Officer
 
Andy G's Avatar
 
City: Pittwater
Country: Australia
Vessel Name: Sarawana
Vessel Model: IG 36 Quad Cabin
Join Date: Sep 2010
Posts: 1,557
Correct use of batteries

I have just replaced our two x 200amp, combination house/starting batteries after five years.

I always use the batteries on the 'both' setting rather than battery 1 or 2 setting.Apart from the obvious downside that if I flatten the batteries, the boat won't start, is there any other reason why this is not a good idea?
__________________
Advertisement

Andy G is offline   Reply With Quote
Old 10-09-2012, 08:59 PM   #2
Guru
 
Moonstruck's Avatar
 
City: Hailing Port: Charleston, SC
Country: USA
Vessel Name: Moonstruck
Vessel Model: Sabre 42 Hardtop Express
Join Date: Nov 2008
Posts: 7,848
Quote:
Originally Posted by Andy G View Post
I have just replaced our two x 200amp, combination house/starting batteries after five years.

I always use the batteries on the 'both' setting rather than battery 1 or 2 setting.Apart from the obvious downside that if I flatten the batteries, the boat won't start, is there any other reason why this is not a good idea?
If they are flooded batteries, 5 years is a pretty good service life. It shows that you have been taking good care of them. You could by monitoring them closely use them one at a time. That would keep one in reserve. Probably a good thing to do in remote places.

You didn't ask, but it would be a good idea to separate your starting and house banks by adding another battery. Just a suggestion as it seems you have been doing OK.
__________________

__________________
Don on Moonstruck
Sabre 42 Hardtop Express & Blackfin 25 CC
When cruising life is simpler, but on a grander scale (author unknown)
http://moonstruckblog.wordpress.com/
Moonstruck is offline   Reply With Quote
Old 10-09-2012, 09:00 PM   #3
Guru
 
djmarchand's Avatar
 
City: East Greenwich, RI
Country: USA
Vessel Name: Bella
Vessel Model: Mainship Pilot 34
Join Date: Aug 2012
Posts: 2,877
No.

David
djmarchand is online now   Reply With Quote
Old 10-09-2012, 09:06 PM   #4
TF Site Team
 
FlyWright's Avatar
 
City: California Delta and SF Bay
Country: Sacramento, CA, USA (boat in Vallejo)
Vessel Name: FlyWright
Vessel Model: Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 10,171
Andy, if you have a bad cell on one battery and its voltage drops and they are tied together in "ALL" or "BOTH", the good battery voltage will be dragged down by the bad battery.

Better to use a combiner to allow both to charge together then automatically separate when the charge stops.
FlyWright is online now   Reply With Quote
Old 10-09-2012, 09:37 PM   #5
Guru
 
Edelweiss's Avatar
 
City: PNW
Country: USA
Vessel Model: 1976 Californian Tricabin LRC
Join Date: May 2011
Posts: 1,834
Quote:
Originally Posted by Andy G View Post
I always use the batteries on the 'both' setting rather than battery 1 or 2 setting.Apart from the obvious downside that if I flatten the batteries, the boat won't start, is there any other reason why this is not a good idea?
-----------------------------------------

From my experience, when the engines are running, It's fine to leave the switch on both. But when you stop, anchor or dock. Switch to one battery or bank. You will get better battery life, avoid an accidental flattening and allows your smart charger to analyze, charge and float each of your batteries at the proper level. If you leave them on both when they're on the charger, all will charge and float at the same voltage.

I have always used flooded batteries ( I have a generator and I'm not afraid to use it, ) and I have one battery bank that is eleven years old and holding fine.
Larry B
Edelweiss is offline   Reply With Quote
Old 10-09-2012, 09:55 PM   #6
Master and Commander
 
markpierce's Avatar
 
City: Vallejo CA
Country: USA
Vessel Name: Carquinez Coot
Vessel Model: 2011 Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 10,254
Despite this photo, I normally keep the "parallel" switch turned to the off position for previously-stated reasons given by others. Having separate battery banks for engine starting versus house is also wise.



A battery monitor for the house bank is also a good idea ...



... here showing an 84.8% charge level.
__________________
Kar-KEEN-ez Koot
markpierce is offline   Reply With Quote
Old 10-10-2012, 06:00 AM   #7
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,518
is there any other reason why this is not a good idea?No, this is the modern way to use batts.

The old 1-2 them actually cuts the bank capacity in half , requiring 2x the discharge from the 1 working batt.

The less any batt is discharged , and the longer SOC is less than 100% the shorter the batt set life.

My question is why "combination " batts , which are usually poorer at either starting or cycling?

In warm climates most "Deep Cycle" batts will easily have the amperage for engine or noisemaker starting.

Since its the down cycling that wears the batt , not the starting any boat that can operate with deep cycles as starts will get longer batt set life.

Boats that operate in the cold ( under freezing) with no block heaters will need start batts to spin the crank faster to build enough heat for self ignition of the fuel.
FF is offline   Reply With Quote
Old 10-10-2012, 10:41 AM   #8
Guru
 
skipperdude's Avatar
 
City: Whittier AK
Country: USA
Vessel Name: Apache II
Vessel Model: 1974 Donald Jones
Join Date: Oct 2007
Posts: 3,147
I would say bad idea.
For the main reason you stated. The boat won't start.

I would always keep the start batterie for just starting the engine.

Nothing worse than dead in the water because you ran the batteries down.

Sd
__________________
If you can't repair it maybe it shouldn't be on the boat
skipperdude is offline   Reply With Quote
Old 10-10-2012, 11:03 AM   #9
Guru
 
Capn Chuck's Avatar
 
Join Date: Jan 2009
Posts: 899
Andy, For what it's worth, our philosophy has always been, if it ain't broke don't fix it. It it has worked for you for 5 years, why would you even wonder if there is a reason to change it? We ran one boat for 17 tears with only a house bank always connected. Don't complicate things if it's not necessary. Chuck
__________________
Blogs
Beach House
Sea Trek
Capn Chuck is offline   Reply With Quote
Old 10-10-2012, 12:18 PM   #10
Senior Member
 
jeffnick's Avatar
 
City: Spartanburg, SC
Country: USA
Vessel Name: Big Duck
Vessel Model: '72 Land-N-Sea
Join Date: Feb 2012
Posts: 425
So basically, you have a single 400a/h battery?
I like knowing I have a fully charged battery in reserve for emergency starts.
jeffnick is offline   Reply With Quote
Old 10-10-2012, 03:00 PM   #11
Guru
 
City: North Charleston, SC
Country: USA
Join Date: Sep 2010
Posts: 4,390
Quote:
Originally Posted by Andy G View Post
I have just replaced our two x 200amp, combination house/starting batteries after five years.

I always use the batteries on the 'both' setting rather than battery 1 or 2 setting.Apart from the obvious downside that if I flatten the batteries, the boat won't start, is there any other reason why this is not a good idea?
If you always leave the switch set on "Both", you don't need the switch, just wire them in parallel and be done with it. That's what the switch is doing in the "Both" position.

You should be reserving one position for engine starting and the other for use while anchored or otherwise without charging current. So - Switch to #1 to start the engine, switch to Both while underway so they both charge, then switch to #2 while anchored and using electrical power such as lights, radio, etc., then switch back to #1 to start the engine and back to Both so they both get recharged.

Or, just install a battery combiner or voltage sensing relay and have it done automatically for you. The part should be under $100 and they are very easy to install.
rwidman is offline   Reply With Quote
Old 10-10-2012, 03:31 PM   #12
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 6,360
R Widman says "switch to both while underway --" On some vessels this may be problematic for the diodes in the on engine alternator dependent upon the type of 1-2- both - off switch you have.
sunchaser is online now   Reply With Quote
Old 10-10-2012, 03:58 PM   #13
Guru
 
skipperdude's Avatar
 
City: Whittier AK
Country: USA
Vessel Name: Apache II
Vessel Model: 1974 Donald Jones
Join Date: Oct 2007
Posts: 3,147
Quote:
Originally Posted by rwidman View Post
If you always leave the switch set on "Both", you don't need the switch, just wire them in parallel and be done with it. That's what the switch is doing in the "Both" position.

You should be reserving one position for engine starting and the other for use while anchored or otherwise without charging current. So - Switch to #1 to start the engine, switch to Both while underway so they both charge, then switch to #2 while anchored and using electrical power such as lights, radio, etc., then switch back to #1 to start the engine and back to Both so they both get recharged.

Or, just install a battery combiner or voltage sensing relay and have it done automatically for you. The part should be under $100 and they are very easy to install.
To much to remember when trying to relax and enjoy a boating experience.
The best way IMHO is 3 on off switches as on Marks Coot.
one for house. One for start and one to combine all batteries for a sure start.

Sd
__________________
If you can't repair it maybe it shouldn't be on the boat
skipperdude is offline   Reply With Quote
Old 10-10-2012, 05:14 PM   #14
Guru
 
City: North Charleston, SC
Country: USA
Join Date: Sep 2010
Posts: 4,390
Quote:
Originally Posted by skipperdude View Post
To much to remember when trying to relax and enjoy a boating experience.
The best way IMHO is 3 on off switches as on Marks Coot.
one for house. One for start and one to combine all batteries for a sure start.

Sd
With the combiner there's no need to remember anything. That was my point. I probably should have been more clear.

If you have a fully charged starting battery but have discharged your house battery (bank) and combine them for starting, the fully charged starting bank will be trying to charge the house bank as it is also trying to start the engine.
rwidman is offline   Reply With Quote
Old 10-10-2012, 05:33 PM   #15
Guru
 
skipperdude's Avatar
 
City: Whittier AK
Country: USA
Vessel Name: Apache II
Vessel Model: 1974 Donald Jones
Join Date: Oct 2007
Posts: 3,147
Are you saying that a full or partial charged start battery will not get juice from a partially charged house bank if the two banks are paralleled.

Sort of like dumping a 1/2 bucket of water into another 1/2 bucket of water to get a full bucket.

Or doesn't it work like that?

In my experience it always seems to work that way. I have had a start bat run down and when I switch the parallel I get more cranks.

SD
__________________
If you can't repair it maybe it shouldn't be on the boat
skipperdude is offline   Reply With Quote
Old 10-10-2012, 06:02 PM   #16
Guru
 
City: North Charleston, SC
Country: USA
Join Date: Sep 2010
Posts: 4,390
Quote:
Originally Posted by skipperdude View Post
Are you saying that a full or partial charged start battery will not get juice from a partially charged house bank if the two banks are paralleled.

Sort of like dumping a 1/2 bucket of water into another 1/2 bucket of water to get a full bucket.

Or doesn't it work like that?

In my experience it always seems to work that way. I have had a start bat run down and when I switch the parallel I get more cranks.

SD
Are you responding to my post?

I am saying that if you have a discharged house battery or bank and you parallel it with a fully charged starting battery or bank and then try to start your engine, the fully charged battery or bank will be trying to charge the discharged bank at the same time it is trying to start the engine. It would be a better plan to start the engine using the starting batery alone and then switch the two together so they can both be charged by the alternator.

If the starting bank is discharged to the point where it cannot start the engine by itself, switching in the house bank may provide enough power to start the engine. It depends on the state of charge of both banks.

If the boat is wired properly with a combiner or VSR, the starting battery will be charged and ready to start the engine unless it is defective or incapable of starting the engine because it doesn't have the capacity to do so in the first place. Or you've run it down trying to start an engine with another problem.
rwidman is offline   Reply With Quote
Old 10-10-2012, 06:05 PM   #17
Guru
 
City: North Charleston, SC
Country: USA
Join Date: Sep 2010
Posts: 4,390
Quote:
Originally Posted by skipperdude View Post
...... Sort of like dumping a 1/2 bucket of water into another 1/2 bucket of water to get a full bucket..........
More like connecting the buckets together with a hose. One is full, the other 1/2 full and you end up with two buckets, each 3/4 full.
rwidman is offline   Reply With Quote
Old 10-10-2012, 06:10 PM   #18
Guru
 
skipperdude's Avatar
 
City: Whittier AK
Country: USA
Vessel Name: Apache II
Vessel Model: 1974 Donald Jones
Join Date: Oct 2007
Posts: 3,147
Ok so how does this happen? Do the electrons flow first to the undercharged bank before performing the work of starting the engine?

I can understand a charger doing that but one battery charging another.
I was not aware that was how it works.

I understand that electrons move at the speed of light. Of coarse taking Ohlms law into account for resistance.

Interesting.

Sd
__________________
If you can't repair it maybe it shouldn't be on the boat
skipperdude is offline   Reply With Quote
Old 10-10-2012, 06:29 PM   #19
JD
Guru
 
JD's Avatar
 
City: New Bern NC
Country: USA
Vessel Name: Stella Di Mare
Vessel Model: Mainship 34t
Join Date: Apr 2010
Posts: 1,702
Quote:
Originally Posted by skipperdude View Post
Ok so how does this happen? Do the electrons flow first to the undercharged bank before performing the work of starting the engine?

I can understand a charger doing that but one battery charging another.
I was not aware that was how it works.

I understand that electrons move at the speed of light. Of coarse taking Ohlms law into account for resistance.

Interesting.

Sd
The charger acts just like another big battery except it is connected to a never ending source, 110VAC. That's what happens when you jump a battery. One is discharged to say 9V, so it can't turn the engine and the other is at 12V. Connect them together and you get 10.5V or so and the engine can start. That is also why you can't start a car if the battery is really low say the lights were left on and they drained every last volt out of the car battery. You can disconnect the car battery and connect the jumpers to the cars cables or you need to charge the car battery awhile so that the car can be jumped off.
JD is offline   Reply With Quote
Old 10-10-2012, 07:00 PM   #20
Guru
 
City: North Charleston, SC
Country: USA
Join Date: Sep 2010
Posts: 4,390
Quote:
Originally Posted by skipperdude View Post
Ok so how does this happen? Do the electrons flow first to the undercharged bank before performing the work of starting the engine?
As soon as you connect the charged battery to the discharged battery, current flows from the charged battery to the discharged battery. Eventually, they will have the same state of charge, somewhere between charged and discharged.

If you're trying to start you engine, the fully charged battery is splitting its power between the starter and the discharged battery.
__________________

rwidman is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 05:00 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012