Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 03-03-2009, 08:51   #1
Registered User
 
theonecalledtom's Avatar

Join Date: Jan 2008
Location: Socal
Boat: Beneteau 36.7
Posts: 386
Images: 1
Equalizing AGMs

Who here has tried equalizing AGMs? What voltage did you do it at and for how long?

Originally I was under the impression that you should never go over the manufacturers max voltage for AGMs but since then I've seen a couple of mentions of equalizing them.

The situation I'm in is that my house bank is pretty old and won't hold a charge - replacing the bank is the next step if I can't improve matters so I'm not sure what I have to lose by trying to equalize, provided they won't explode, melt etc.
theonecalledtom is offline   Reply With Quote
Old 03-03-2009, 10:06   #2
CF Adviser
Moderator Emeritus
 
Hud3's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: Virginia
Boat: Island Packet 380, now sold
Posts: 8,942
Images: 54
Dave, a tech guy at Lifeline Batteries (AGM manufacturer), says to charge them fully first, and then apply a constant voltage of 15.5 VDC for eight hours. Equalizing will reduce the lifespan a bit, but will improve performance when they've lost some of their capacity.
__________________
Hud
Hud3 is offline   Reply With Quote
Old 03-03-2009, 10:19   #3
Registered User
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 8,462
And Trojan says that you should NOT equalize AGM or GEL batteries.

http://www.trojanbattery.com/Product...nglish_001.pdf
DeepFrz is offline   Reply With Quote
Old 03-03-2009, 12:37   #4
Registered User
 
theonecalledtom's Avatar

Join Date: Jan 2008
Location: Socal
Boat: Beneteau 36.7
Posts: 386
Images: 1
I think in my browsing I've read a lot more "dont do it" than "do it". However I figure that if I'm about to replace the batteries then I don't stand to lose much unless its dangerous.

Has anyone on this board actually done it?
theonecalledtom is offline   Reply With Quote
Old 03-03-2009, 13:53   #5
Registered User

Join Date: Jul 2005
Location: Bellingham
Boat: Outbound 44
Posts: 9,319
This AGM equalization procedure used to be on the Lifeline website. I don't see it there now. But here is a copy:
Lifeline AGM Batteries Charging Procedure

Paul L
Paul L is offline   Reply With Quote
Old 03-03-2009, 14:25   #6
Registered User
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 8,462
Tom, I have read here somewhere (I believe on this forum) that the capacity of the battery bank (AGM) can be, at least for the most part, restored by draining the bank down to about 11 volts and then fully charging. It may take several cycles to get the capacity up. They aren't fully restored but the procedure adds significant life to the batteries at times when the battery capacity has dropped prematurely due to improper charging.
DeepFrz is offline   Reply With Quote
Old 04-03-2009, 05:57   #7
Registered User

Join Date: May 2003
Location: East Coast & Other Forums!
Posts: 917
Each AGM battery is different. You need to CALL your mfr. to see if ANY EQ is possible and if so, at what Volatage and for how long. Otherwise, don't attempt it.
__________________

camaraderie is offline   Reply With Quote
Old 04-03-2009, 12:44   #8
Registered User
 
theonecalledtom's Avatar

Join Date: Jan 2008
Location: Socal
Boat: Beneteau 36.7
Posts: 386
Images: 1
Quote:
Originally Posted by camaraderie View Post
Each AGM battery is different. You need to CALL your mfr. to see if ANY EQ is possible and if so, at what Volatage and for how long. Otherwise, don't attempt it.
Don't because I'll break already broken batteries or don't because its dangerous?

I'll start with the discharging and recharging in a controlled manner idea to see if it helps. Calling the mfgs is a good idea - I think they are lifelines. Old, abused, lifelines.
theonecalledtom is offline   Reply With Quote
Old 05-03-2009, 09:44   #9
Registered User

Join Date: May 2003
Location: East Coast & Other Forums!
Posts: 917
Tom...if they are indeed Lifelines...you are in luck. Lifeline now call equalizing a conditioning charge which you should apply for 8 hours in a WELL ventilated space. The voltage used is dependent on ambient temperature as follows:
40 16.2
50 16.0
60 15.85
70 15.7
77 15.6
80 15.5
90 15.4
100 15.3
110 15.2
120 15.1
130 15.0
140 15.0
150 15.0
160 15.0
Over 160...shut it down!!
Note that you should bring the batteries to 100% charge before doing this. I've rounded off the voltages to the nearest tenth. Note the ventilation remarks!!
Do not do this with other AGM's unless you have confirmed SAFETY with the mfr.
Yes..AGM's can explode scattering a lot of nasty stuff if they get to overtemperature thermal runaway through overcharging!!
Suggest that even with Lifelines, you monitor temperature and do not permit the batteries to get over 160 degrees.
__________________

camaraderie is offline   Reply With Quote
Old 05-03-2009, 14:10   #10
Registered User

Join Date: Jan 2005
Location: Seattle area (Bremerton)
Boat: C&C Landfall 39 center cockpit "Anahita"
Posts: 1,077
Images: 6
Temperature limit of charging

It is not advisable to equalize any lead-acid battery at or above 120 deg F. Even near that temperature it requires a voltage-limited constant-current charger with good line and load regulation specs.

Most "marine" chargers are not up to this task. I've been equalizing (bringing back from the dead) AGM and gel-cell batteries for 20 years and it can be done. Those batteries which will not recover will exhibit a wide temperature range from cell-to-cell...this is one good indicator as to whether or not one will be successful.
__________________
"I don't think there'll be a return journey Mr. Frodo". Samwise Gamgee
Rick is offline   Reply With Quote
Old 06-03-2009, 04:26   #11
Registered User
 
Beach Cruiser's Avatar

Join Date: Apr 2004
Location: Cruising
Boat: Victory V35 - Beach Cruiser
Posts: 88
We have a Magnum charger/inverter and it has 2 agm settings. One for Lifeline batteries and the second for all other agm. Only the setting for Lifeline will allow us to equalize.

Barry
Beach Cruiser is offline   Reply With Quote
Old 14-03-2009, 14:01   #12
Registered User
 
Extemporaneous's Avatar

Join Date: Dec 2007
Location: Canada
Boat: Corbin 39 Special Edition
Posts: 909
Quote:
Originally Posted by theonecalledtom View Post
Don't because I'll break already broken batteries or don't because its dangerous?

I'll start with the discharging and recharging in a controlled manner idea to see if it helps. Calling the mfgs is a good idea - I think they are lifelines. Old, abused, lifelines.
I am now looking at Lifelines.
Do you know how old yours are?
Or how much abuse (and still gave acceptable performance) they have taken?
Do you know which model or size they are?
Any other comments about the Lifelines?
How has the discharge recharge regime worked out (if you know yet)?

An comments would be appreciated.
Extemp.
Extemporaneous is offline   Reply With Quote
Old 14-03-2009, 14:05   #13
Registered User
 
Extemporaneous's Avatar

Join Date: Dec 2007
Location: Canada
Boat: Corbin 39 Special Edition
Posts: 909
Quote:
Originally Posted by Beach Cruiser View Post
We have a Magnum charger/inverter and it has 2 agm settings. One for Lifeline batteries and the second for all other agm. Only the setting for Lifeline will allow us to equalize.

Barry
A little off topic, but I see you have a Magnum charger/inverter.
Have you noticed much RFI?
Is it a true Sine Wave model?
Do you like it?
Any other comments about it?

Thanks,
Extemp.
Extemporaneous is offline   Reply With Quote
Old 14-03-2009, 14:25   #14
Registered User

Join Date: Mar 2009
Location: Norfolk Virginia
Boat: Nordic 44 - Destiny
Posts: 8
I bought my 8D Lifelines in 2000, before we went cruising, and finally got rid of them in 2007, while in Venezuela. I would have replaced them with AGMs if they had been available there. I did 'equalize' them a few times according to directions I got from Lifeline. I used a Freedom 20 inverter/charger and set it to 'warm wet cell' to do the charge since that was closest to the voltage recommended by Lifeline (done after emails back/forth with the tech guy at Lifeline). I then monitored the process very closely, watching the amount of amps going in (very little) and the voltage. The batteries were fully charged when I did it. I shoul point out that I probably could have gotten a longer life out of them but I made several mistakes (undercharging) when they were new (I was using the wrong setting on my charge controller and didn't realize it).
HTH,
Larry
lerudnick is offline   Reply With Quote
Old 14-03-2009, 15:01   #15
Registered User
 
Beach Cruiser's Avatar

Join Date: Apr 2004
Location: Cruising
Boat: Victory V35 - Beach Cruiser
Posts: 88
I have a MS-2012 pure sine wave unit. I am very happy so far, but I have only been using it for a few months. I have not noticed any RFI.

Right now we are in the Abacos and I am spending all my time at anchor. I charge mostly with solar and wind, but I have a Honda eu2000i generator that I use for running the water heater and occasionally charging. I really like the fact that I can change the amps the charger puts out. This allows me to control the load on the Honda.

The optional battery monitor is excellent.

Barry

Quote:
Originally Posted by Extemporaneous View Post
A little off topic, but I see you have a Magnum charger/inverter.
Have you noticed much RFI?
Is it a true Sine Wave model?
Do you like it?
Any other comments about it?

Thanks,
Extemp.
Beach Cruiser is offline   Reply With Quote
Reply

Tags
agm

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
3 stage regulator or internal regulator for AGMs? sgtPluck Electrical: Batteries, Generators & Solar 13 05-09-2008 08:50

Advertise Here


All times are GMT -7. The time now is 12:22.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.