Reply
 
Thread Tools Display Modes
 
Old 11-18-2012, 06:29 AM   #21
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,531
"2) As a bank ages, capacity reduces."

One usual reason for this is the failure to recharge to 100% full each and every discharge.

As the last 10% takes "forever" most noisemaker folks wont bother.

Only solar ( wind is too loud ) seems to be able to get top 100% with great regularity.

The system should be sized so the boat can live between 50% and 85% SOC , and allow for the system shrinkage that is normal with only 85% recharges.
__________________
Advertisement

FF is offline   Reply With Quote
Old 11-18-2012, 09:36 AM   #22
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 6,372
My last set of Trojan 105s (house) went for 8 years with about 90% effective capacity still remaining, so said the Link monitor. Like tires, I replace batteries early but had I tried could have probably got another year or two out or them.

For several years I sold lead to battery manufacturers and learned about wet acid battery construction, some companies do it better than others. A quick read of Consumer Reports says the same, Die Hard always seems to top the list for cars. As stated by manufacturers, long battery life is normally related to using better marine rated charging systems, keeping them above 50% rated capacity and re-charging fully as says FF. For house, I've used Trojan brand for the past 30 years and never been let down. My industrial experience showed using NAPA with a 48 month guarantee was the most effective solution for large diesel engine starting.

If you enjoy gassing every year or so, you may add another few years of useful life, to your house batteries that is. This subject can become highly charged. Thanks P/F for starting it.
__________________

sunchaser is offline   Reply With Quote
Old 11-18-2012, 09:44 AM   #23
Guru
 
City: North Charleston, SC
Country: USA
Join Date: Sep 2010
Posts: 4,390
Quote:
Originally Posted by caltexflanc View Post
................... As a bank ages, capacity reduces. ...........
Correct. And that's why. unlike a fuel tank, you cannot determine the remaining power by calculating power used against power added (by charging).

Another factor is the recommendation to use no more than 50% of the capacity, then recharge. Even ignoring that recommendation, unlike the fuel system where the last gallon of fuel is as good as the first, as the battery nears discharge, the voltage lowers to the point where many loads won't work properly or at all.
rwidman is offline   Reply With Quote
Old 11-18-2012, 10:20 AM   #24
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 6,372
But Ron, ultimate battery life is up to the abuser/user. Waving a hydrometer around is like using a thermometer for deducing if you have a hangover. Like many things in life, treat batteries right and they go for a long time. Just like diesels.

Another way to look at it is why does a routinely waxed boat look better and have higher resale value longer than its unwaxed counterpart - because the owner cares. The list of care vs life goes on and on, indeed including lead, acid and allowable voltage fluctuation.
sunchaser is offline   Reply With Quote
Old 11-18-2012, 10:51 AM   #25
Guru
 
Phil Fill's Avatar
 
City: Everett Wa
Country: US
Vessel Name: Eagle
Vessel Model: Roughwater 58 pilot house
Join Date: Oct 2007
Posts: 2,919
Sq





I started this disvussion to give a cheap siple way of estimating % of charge left. Not to start a long discussion. I check the batteries omce a month. The batteries last an average of 7 years. Use it. Dont use it. Its up to you.
Phil Fill is offline   Reply With Quote
Old 11-18-2012, 11:04 AM   #26
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 6,372
P/F

Of course you know there is no such thing as a short discussion on TF regarding something 100% of us have buried in our hulls.
sunchaser is offline   Reply With Quote
Old 11-18-2012, 03:15 PM   #27
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,920
Quote:
Originally Posted by Phil Fill View Post
Sq





I started this disvussion to give a cheap siple way of estimating % of charge left. Not to start a long discussion. I check the batteries omce a month. The batteries last an average of 7 years. Use it. Dont use it. Its up to you.
The reason it turned into a discussion is there is disagreement whether your method is "good enough".
psneeld is offline   Reply With Quote
Old 11-18-2012, 06:58 PM   #28
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,573
Quote:
Originally Posted by FF View Post
Only solar ( wind is too loud ) seems to be able to get top 100% with great regularity.
90 watts of solar to each (of 2) 200ah wet cell batteries keeps them full and pretty much supplies day fridge use. 90watts x2 does much more than maintain, 25watts should do that, it does for the genset 150ah battery. Panels are getting cheaper, your first cost of installing is your last cost, but do fit a regulator (90w ones have equalization, but not the 25w panel).
Your batteries will appreciate the charge, top them up at least monthly.
__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 11-18-2012, 08:16 PM   #29
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
Quote:
Originally Posted by Phil Fill View Post
Sq





I started this disvussion to give a cheap siple way of estimating % of charge left. Not to start a long discussion. I check the batteries omce a month. The batteries last an average of 7 years. Use it. Dont use it. Its up to you.
Phil, staring a thread is a bit like having kids, your create them but where they end up is out of your hands.
Andy G is offline   Reply With Quote
Old 11-18-2012, 11:53 PM   #30
Newbie
 
City: Kent Narrows, MD
Country: USA
Join Date: Oct 2012
Posts: 3
If I may make a contribution to this discussion, I am an electronic technician and some years ago I did some research into the discharge/charge performance of gel lead acid batteries for my employer. My more useful and recent experience is with a 105 amp hour deep cycle battery I bought from K Mart to run a trolling motor on my canoe. I believe its draw was about 35 amps wide open. When underway I kept a small quality digital multimeter (3 1/2 digits) connected across the battery so I could watch the voltage fall. Running the motor at a little less than full power I got 4 or 5 hours cruising before the voltage fell to 11.1 to 11.5 volts. This is clearly more than the recommended discharge to 50% charge level (probably down to 10-20%) and the motor was running noticeably slower.

Rules for maximum life span (number of charge cycles) for a lead acid battery:
1. Always keep the battery fully charged.

2. Always keep the water level above the top of the plates.

Obviously Rule 1 isn't practical for yacht house banks; they are going to sit partially discharged for one or more days before recharging. This problem will be solved when the price of lithium ion batteries becomes reasonable and to a lesser extent lithium polymer batteries. LI batteries couldn't care less if you discharge them to 0%. In fact I have read that if you are going to store them for any length of time they should be discharged fully first! Talk about the very opposite from lead acid. The problem here with lead acid batteries is that as they are discharged a layer of lead sulfate forms on one of the two battery plates. It is normally removed by the charging current but the longer you wait to recharge the harder the sulfate gets and in a short time it isn't removeable by normal charging voltages. Intelligent battery chargers' equalization function applies 16-16.5 volts to blast the sulfate loose or cause it to dissolve in the electrolyte. Sounds brutal to me!

I dealt with rule one by putting the battery on charge as soon as I got home. I used a simple minded $25 Auto store 10 amp charger which I left connected all night.

The fully charged voltage of a lead acid battery is 12.70 volts. I seldom if ever saw more than 12.69 volts. The battery has to be open circuit-no connections, or battery switch off, and it must have rested about 24 hours to remove the surface charge on the plates that forms during recharge- this is a layer of hydrogen bubbles that cover the plates. This surface charge is why you must apply higher voltages to recharge the battery- 13.7 volts in the beginning, rising to 14.4. Until this surface charge is removed the voltmeter reading is of no use.

But! You don't have to wait 24 hours! A small discharge current for a minute or two should do the trick. I have read several times that if you have been driving your car for awhile and want to check the battery voltage, just shut off the engine and turn on the headlights (about a 20 amp load) for 1-2 minutes, then turn them off. Then you should get a voltage of 12.70 volts or less if the battery has been fully recharged. Watch the voltmeter for 15-20 seconds to see if it rises. If it does, wait until it stops rising and you have your true open circuit rest voltage. It worked for me.

If you had an accurate table of terminal open circuit rest voltages versus %discharge you should be able to accurately determine the state of charge. The reason that intelligent chargers can't perform this simple test is that during charging, they have no quick way to remove the surface charge before measuring.

I apologize if this is longwinded but battery chemistry is not so simple and there is a lot of misinformation flying around,
Edistoart is offline   Reply With Quote
Old 11-19-2012, 12:22 AM   #31
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,573
There you are Phil, an electronic tech, using both theory and practical testing, agrees: you get good guidance on battery state of charge from voltage.
__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 11-19-2012, 07:44 AM   #32
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,531
The batteries last an average of 7 year

Easy to do if you only leave the dock a couple of times a year!
FF is offline   Reply With Quote
Old 11-19-2012, 09:24 AM   #33
Guru
 
jleonard's Avatar
 
Join Date: Jun 2008
Posts: 2,740
Quote:
Originally Posted by Phil Fill View Post
Sq





I started this disvussion to give a cheap siple way of estimating % of charge left. Not to start a long discussion. I check the batteries omce a month. The batteries last an average of 7 years. Use it. Dont use it. Its up to you.
Phil,
I had been using "your" method for many years. I installed a Link Lite and used that this past summer, but still fall back to use the voltage method using the Link's readings..
I also get good battery life, so I will continue to use the voltage method.
__________________
Jay Leonard
Attitude Adjustment
40 Albin
Mystic,Ct. /New Port Richey,Fl
jleonard is offline   Reply With Quote
Old 11-20-2012, 06:46 AM   #34
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,531
For folks that wish to use Voltage , it would pay to install a spot or pick up point where even a cheap radio shack $7.00 digital meter can do the measuring.

An analog gauge is usually not accurate enough for meaningful measurements.
FF is offline   Reply With Quote
Old 11-20-2012, 07:59 AM   #35
Guru
 
City: North Charleston, SC
Country: USA
Join Date: Sep 2010
Posts: 4,390
Quote:
Originally Posted by BruceK View Post
There you are Phil, an electronic tech, using both theory and practical testing, agrees: you get good guidance on battery state of charge from voltage.
I am an electronics technician also. I just look to see how bright my lights are and how dim they get when the water pump comes on.
rwidman is offline   Reply With Quote
Old 11-20-2012, 01:10 PM   #36
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: 10,189
For the cost of 50 gals of diesel, you can pick up a monitor and get any reading you want at the push of a button. Seems like a no-brainer when it comes to health of battery banks that exceed $500 in value.
__________________
Al

Custom Google Trawler Forum Search
FlyWright is online now   Reply With Quote
Old 11-20-2012, 09:12 PM   #37
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: 10,265
Quote:
Originally Posted by FlyWright View Post
For the cost of 50 gals of diesel, you can pick up a monitor and get any reading you want at the push of a button. Seems like a no-brainer when it comes to health of battery banks that exceed $500 in value.
Yeah. Get a battery monitor.

__________________
Kar-KEEN-ez Koot
markpierce is offline   Reply With Quote
Old 11-23-2012, 04:46 PM   #38
Guru
 
dhmeissner's Avatar
 
City: Seattle
Country: North America
Vessel Name: The Promise
Vessel Model: Roughwater 35
Join Date: Sep 2012
Posts: 1,326
Quote:
Originally Posted by BruceK
There you are Phil, an electronic tech, using both theory and practical testing, agrees: you get good guidance on battery state of charge from voltage.
So does this one.

Sent from my iPad using Trawler
__________________
Dave & Suzie - Roughwater 35
http://thepromiserwb1029.org/2012/09...the-promise-2/
dhmeissner is offline   Reply With Quote
Old 11-23-2012, 09:16 PM   #39
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,721
I scanned this thread and see no mention of battery type.

When we installed AGM batteries we were told charging voltage was 14 or so and fully charged seemed to be about 12.8. I think 10.5 was dead.

I usually charge my entire bank of two AGM house batts and one AGM high current start batt when my voltage goes down to 12.2 to 12.5 volts.

If I had standard flooded lead/acid batts all the above voltages would be lower.
One's charger should be adjusted to voltages appropriate to battery type.

All numbers are rough recollection.
__________________

__________________
Eric

North Western Washington State USA
Nomad Willy 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 01:25 AM.


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