Use of AGM/Glass mat batteries - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
  #1  
Old 02-24-2001
Junior Member
 
Join Date: Feb 2001
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
santorinidon is on a distinguished road
Use of AGM/Glass mat batteries

I am thinking of switching from wet-cell batteries to AGM batteries. Would like to hear from anyone who has used these batteries, and could I except signicantly longer life from AGM batteries.
Reply With Quote Quick reply to this message Share with Facebook
  #2  
Old 02-24-2001
Member
 
Join Date: Dec 2000
Posts: 60
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 14
Constantin is on a distinguished road
Use of AGM/Glass mat batteries

Don,
The life of any battery is a function of its duty cycle, the quality of its construction, and the maintenance it received. Some flooded cells like the CS series from Rolls/Surrette will last longer than AGMs under ideal conditions.

However, the many benefits of AGMs (little self-discharge, high efficiency, no spill, low chance of fumes, little maintenance, etc.) have made me convert over.

Particularly if you use your main engine to recharge your banks and bulk charge each day, will the higher charge acceptance and efficiency of AGMs end up making them a cheaper option than flooded cells. More on that on my web-site: http://www.vonwentzel.net

I go through the benefits of AGMs and also have a bulk-charging battery model available that you can customize to compare batteries based on your specifications.
Reply With Quote Quick reply to this message Share with Facebook
  #3  
Old 03-01-2001
Senior Nappy Headed Ho
 
Join Date: Feb 2001
Posts: 734
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Denr is an unknown quantity at this point
Use of AGM/Glass mat batteries

Santorinidon:
Do make sure before you abandon the wet cell batteries that your charger is compatible with the AGM batteries. AGM batteries have a recommended charging voltage and procedure. If you deviate from this recommendation you''ll get no better life or performance from the AGM batteries than you would from the "wet ones"! You might want to add another battery to your bank as the AGM batteries have lower AMP hour capacities as compared to wet cells. Check this out very carefully.
Reply With Quote Quick reply to this message Share with Facebook
  #4  
Old 03-03-2001
Member
 
Join Date: Dec 2000
Posts: 60
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 14
Constantin is on a distinguished road
Use of AGM/Glass mat batteries

The amp hour capacity of AGMs per unit volume is usually the same if not higher than premium flooded cells. Only the cheapest of flooded cells will have higher Ah capacities (due to very thin Pb plates) but will have correspondingly shorter lifespans.

AGMs are a premium energy storage system. As such, they deserve a charge system that is worthy of them. I''d make sure the system on board is capable of dealing with AGMs and that the charging voltages are set correctly. These voltages do not differ very much from flooded cells (unlike Gel) and thus even a "flooded" setting on a regulator is unlikely to damage an AGM.

The primary difference is the bulk stage where AGMs can be recharged up to 18x faster than flooded cells. Not too many people have that kind of charging capability on board... Anyway, see my website mentioned above for sizing and other considerations.
Reply With Quote Quick reply to this message Share with Facebook
  #5  
Old 07-12-2006
Junior Member
 
Join Date: Apr 2006
Location: NH
Posts: 18
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
captw3 is on a distinguished road
I added a bank of 2 series 31 AGM batteries as a house bank with a flooded cell series 27 for the engine starter. I used a combiner with a high voltage sensor to charge the banks in unision unless the flooded cell draws at a higher rate, ( above 14.2 volts ) then the sensor disconnects the AGMs until the flooded cell charge rate drops and the combiner ties them together again. I used a Yandina combiner.
Reply With Quote Quick reply to this message Share with Facebook
  #6  
Old 07-13-2006
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,291
Thanks: 0
Thanked 11 Times in 11 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
Definitely have to check your charger, as AGM batteries like to be charged at a lower peak voltage than wet cell batteries. The are more susceptible to serious damage from overcharging or charging at too high a voltage.
__________________
Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
Reply With Quote Quick reply to this message Share with Facebook
  #7  
Old 07-13-2006
Member
 
Join Date: Apr 2006
Location: Spokane, WA
Posts: 93
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
dave.verry is on a distinguished road
AGM batteries are known in the industry as VRLA (valve regulated lead acid). These batteries have a stringent charge requirement to prevent a condition known as thermal runaway at high temperatures and maintain full charge at low temperatures. Without the proper charger these batteries have been known to explode at high temperatures (such as a boat in the sun w/o ventilation). Admittedly, these explosions have happened as far as I know only in industrial settings. I have never heard of one happening on a boat, but there is always a first time. I have yet to see a marine charger with temperature compensation (lowering the float or charging voltage at high temperature and raising it at low temperature). They may be out there, if so, those of you who have sealed batteries should invest in one.

As an electrical engineer who has specialized in DC power, i.e. battery charging, I have flooded (or wet) cells on my boat. They can take much more abuse; can tolerate a deeper discharge, more discharge cycles, higher & lower temperatures then sealed batteries. Wet cells vent the hydrogen that sealed batteries store, under pressure, within the cells. That does not mean that sealed batteries don’t vent, that’s what the valve is for, to vent pressure, i.e. hydrogen that builds up during use/abuse. A good wet cell should outlast a AGM cell considerably. Just make sure the water in the cells is always topped off.

Always vent the battery compartment, weather you are using wet or VRLA batteries, to the outside to prevent hydrogen gas build-up. Hydrogen is very volatile (explosive) but fortunately is lighter then air.
Reply With Quote Quick reply to this message Share with Facebook
  #8  
Old 07-15-2006
camaraderie's Avatar
moderate?
 
Join Date: May 2002
Location: East Coast
Posts: 13,877
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 15
camaraderie is a jewel in the rough camaraderie is a jewel in the rough camaraderie is a jewel in the rough
Wet cells on a boat are a pain to maintain and most (not the real expensive ones) wear out relatively quickly in the heavy duty cycling of live aboard use. This is anecdotal based on my own experience and that of many fellow cruisers I've chatted with.Whether this is due to poor maintenance or deep discharging or simply design factors is not something I know enough about to comment on...but I can say that despite my attempts at good maintenance and proper cycling, I have been disappointed in wet cells (East Penn Mfg. & West Marine 8D's).
On the other hand, I am well pleased with the trouble free nature of my present AGM bank which also seems much more robust after over a year in everyday use. No real worries about charging with these compared to wet cells...it is the Gel Cells that require less than 14.1V bulk charging.
Reply With Quote Quick reply to this message Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sulphated batteries drynoc Gear & Maintenance 6 05-11-2005 07:29 PM
Golf cart batteries hathanger Gear & Maintenance 8 03-13-2005 04:23 PM
Batteries tm3 Gear & Maintenance 20 12-08-2003 04:10 PM
AGM batteries has any one used them obiec Gear & Maintenance 4 04-04-2003 12:27 PM
battery nightmares pmills42255 Gear & Maintenance 9 03-16-2003 08:17 AM


All times are GMT -4. The time now is 11:18 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.