Equalizing batteries

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Steve Laume
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Joined: Feb 13th, '05, 20:40
Location: Raven1984 Cape Dory 30C Hull #309Noank, CT
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Equalizing batteries

Post by Steve Laume »

I currently have two Lifeline, group 27, AGM batteries aboard my boat. The only regular monitoring I have is the original CD volt meter that seems to be accurate to + or - a volt or there abouts. I check the batteries with a hand held digital meter at times. I never seem to be able to get them to maximum charge and this seems to indicate it is time to equalize them. The Lifeline web site suggests charging to full capacity, then charging at 15.5 volts for 8 hours. That seems simple enough. Now how do I get a charger to put out 15.5 volts, and does charger amperage come into play at all? I want to make some changes in the battery management of my boat but I am just not sure what is needed. I had thought the Link 20 seemed like to right instrument for the job but now it seems as if it is being phased out. One thing I can't begin to understand is how I can go to Sears and buy a digital multi meter for $9.99 and a simple single function digital volt meter costs $99.99, Steve.
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Clay Stalker
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Joined: Feb 5th, '05, 12:07
Location: 17' Town Class Sloop

Alternator?

Post by Clay Stalker »

Hi Steve:

What kind of a charging system (alternator) do you have? Unless you have a "smart" system, somewhat complicated, you might be better off with basic, group 27 wet cell batteries....previous posts have discussed at length the benefits of the different types of batteries...I personally came to the conclusion that with my stock alternator I was better off with a couple of group 27 100 amp wet-cells...they certainly have advantages and disadvantages, but have not failed me yet as I use them. Others on the board, most with more electrical knowledge then I, have some pretty complicated systems that work well for them...

Clay
Clay Stalker
Westmoreland, NH and Spofford Lake, NH
Boyd
Posts: 403
Joined: May 9th, '05, 10:23
Location: CD 30 MkII

AGM's

Post by Boyd »

Hi:

I had a set of AGM"s several years ago and it was my understanding from their literature that you NEVER equalize that type of battery. I know of RV owners who have over charged AGM's and caused them to swell and die. If LifeLine has changed their recommendations then the only option I know to equalize these batteries is a "Smart" 3 stage charger. Most of them (Xentrix) for example have "equalizing" cycles that you initiate by pushing a special recessed button. Personally I never equalize even wet cell batteries.

After a very bad experience with AGM's I went to golf cart batteries. They are so cheap that when I even suspect a battery I just replace it.

Boyd
s/v TERN
CD30 MkII
Fort Lauderdale, Fla.
Leo MacDonald
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Joined: Feb 5th, '05, 21:00
Location: 'EVENING LIGHT' CD33 No. 38, Pine Isl. Bay, Groton, CT

Post by Leo MacDonald »

Hi Steve,

With correct battery management in mind, a Link-20 is a real good investment. As is an aftermarket Alternator and 3-Stage Regulator.

A lot has been previously discussed in this area. Search for "AGM"
or “Leo” and “AGM”

Fair Winds,
Leo MacDonald
"Evening Light" CD33 No. 38
Pine Isl. Bay, Groton, CT
Fair Winds,
Leo MacDonald
Founding Fleet Capt., NE Fleet
Past Commodore, Member No. 223
A 'Cape Dory Board' supporting member ~1999 to ~2015 :-)
L.DeMers
Posts: 21
Joined: Dec 5th, '05, 18:00
Location: CD30c "DeLaMer"
Sailing Lake SUperior

Equalizing AGM's

Post by L.DeMers »

I searched the internet for information on equalization of AGM's, and the only opinion that I got was to NOT do it. On the Lifeline Battery site, there is no reference to equalization that I could find.

I would not do it. The higher voltage is a critical value. generally, 15.5v is considered the most that an AGM can stand before there is internal damage done to the battery (I suspect that the high voltage will puncture through the plate separators, causing an internal short between plates). Another reason not to is that the AGM is a sealed battery, so the active gassing that occurs in the equalizing stage will create venting problems, and possibly explode the battery (since they are sealed). You only gain a 5% advantage in capacity too.
I would recommend that you get a good high frequency 3 stage battery charger that includes an AGM setting. Properly charging your bank is the way to keep it alive and kicking. AGM's are expensive batteries too, so I would not exceed the manufacturers charging rates.

Personally, I like Trojan T105's (6v golf cart batts.) I have 440 Ah capacity now, in two banks..reefer and house. I also have a dedicated truck type (non deep cycle) starting battery, that is now 10 years old and in great condition.

To charge and monitor your boat power bank, get a LINK 2000, and a battery combiner. This will send the battery charge where it is needed, and it will tell you the condition of each bank of batteries, like a fuel gauge (ie: full thru empty are graphicly shown).

Then you will know enough about your battery banks to maintain them safely and effectively.

Contact me offline if you want.

Larry DeMers
s/v DeLaMer
Cape Dory 30
Lake Superior
Larry DeMers
S/V DeLaMer
Cape Dory 30c
Lake Superior
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Steve Laume
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Joined: Feb 13th, '05, 20:40
Location: Raven1984 Cape Dory 30C Hull #309Noank, CT
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Equalizing on Life line site

Post by Steve Laume »

I found the site that suggested equalizing AGM batteries. http://www.lifelinebatteries.com/manual.php
On page two they specify the voltage and time. Some where else I had read this should only be done when capacity is lost and once a year at most. It seems like I would need a shore powered charger that has an equalization mode to accomplish this if it proves prudent. I really like the idea of no maintainance of fluid levels and no chance of an acid leak in the boat. Life is a compromise, Steve. [/u][/url]
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