Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 07-01-2011, 10:01   #1
Registered User
 
Capt.Don's Avatar

Join Date: Aug 2010
Location: Altadena, CA
Boat: Tartan 3500
Posts: 610
Images: 1
Life Expectancy Group 27 AGM Batteries

Surveyor recommended replacing 6 year-old Group 27 AGM batteries. What is a reasonable life expectancy of these? Currently (no pun intended), they hold a charge and the engine starts. Do you I have a couple more years before they require replacing?
__________________

__________________
Capt.Don is offline   Reply With Quote
Old 07-01-2011, 11:17   #2
Senior Cruiser
 
roverhi's Avatar

Cruisers Forum Supporter

Join Date: Aug 2005
Location: Kona, Hawaii, Carlsbad, CA
Boat: 1969 Pearson 35 #108 & 1976 Sabre 28
Posts: 6,002
Send a message via Yahoo to roverhi
Heard of some people claiming 10 years for these batteries. Of course others have had theirs crap out in a couple of years which makes their added cost a questionable investment. It all depends on where you're going and what your needs are. Batteries seldom die without some warning. If you can live with going down to the boat and hearing the click of death when you turn the key or worse yet off on a sail, don't worry, be happy. But be ready to swap a new battery in the moment they show signs of not holding a charge. If you absolutely have to have the confidence that the battery will start the engine, the batteries are overdue for replacement.
__________________

__________________
roverhi is offline   Reply With Quote
Old 07-01-2011, 11:55   #3
Registered User
 
Capt.Don's Avatar

Join Date: Aug 2010
Location: Altadena, CA
Boat: Tartan 3500
Posts: 610
Images: 1
Roverhi - thanks. I've also seen claims of 10 years.

The batteries have been on a Heart 1000 charger/inverter. Boat has been unused with batteries on shore power/charger for 6 months. Prior to that, the boat had minimal use - mostly shore power and an occasional sail around the bay.

Is there a way to check their health other than waiting for the "click of death"? Would an auto shop battery tester tell me anything?
__________________
Capt.Don is offline   Reply With Quote
Old 07-01-2011, 11:59   #4
Registered User

Join Date: Jan 2010
Location: Wells, Vt
Boat: 42ft Colvin Gazelle - TLA HLA
Posts: 504
So much depends. Are they showing signs of failure? I certainly wouldn't just get new ones because of their age. Good agms that aren't overcharged can go a long time. With the extra cost involved in agms it is worth taking them as far as you can. If you are headed someplace where batteries aren't available (or agms in particular if you feel you have a need for them) then it might be worth replacing just for the heck of it but there certainly aren't any garentees there iether. Well, there might be but they won't do you any good if you are in the place where the batteries aren't and if you're in a place where they are then might as well replace them when they are no longer acceptable. Years don't nescessarily equate to cycles directly and so long as they have been left in fully charged state some agms are reported to have great storage life, unlike wet cells which have high self discharge rates and require regular care. If they are in good shape and six years old the charging set up is probably right and you may be fine for many more to come. You can check their condition realizing their specs and that degradation happens with time and use. Will they take full charge? Does amp hour drain equate to charge level? Ultimately, are they suitible for your intended use? Only you can answer. But I certainly wouldn't go looking to drop that kind of money unless there was a reason. If you do, however, I'm sure there would be a happy cruiser in your neck of the woods who would take the old ones off your hands...
__________________
ConradG is offline   Reply With Quote
Old 07-01-2011, 12:09   #5
Registered User

Join Date: Jan 2010
Location: Wells, Vt
Boat: 42ft Colvin Gazelle - TLA HLA
Posts: 504
Quote:
Originally Posted by Capt.Don View Post
Roverhi - thanks. I've also seen claims of 10 years.

The batteries have been on a Heart 1000 charger/inverter. Boat has been unused with batteries on shore power/charger for 6 months. Prior to that, the boat had minimal use - mostly shore power and an occasional sail around the bay.

Is there a way to check their health other than waiting for the "click of death"? Would an auto shop battery tester tell me anything?
Yes. If you have monitor and understand voltage and amps and rest periods, you can watch performance yourself. There are some very sophisticated analizers out there also (see oddysey battery analizer and the like) and probably your auto parts store will have one that's good enough. If I were you I'd fully charge them. Give them a rest with no load and check the voltage accurately. Then give them a known discharge in amps (somewhere around 50% total spec'd amp hrs), give them a rest and check again. Should give you an idea of how "good" they are or at least if they are good enough for your intended use. But perhaps a good book on batteries would be the first step?
__________________
ConradG is offline   Reply With Quote
Reply

Tags
agm, battery

Thread Tools
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
Life Expectancy of a Yanmar 3GM30 clausont Engines and Propulsion Systems 27 10-09-2017 01:24
Chartplotter Life Expectancy Shorty Marine Electronics 11 10-11-2010 08:05
Perkins 4-108 Life Expectancy ????? cburger Engines and Propulsion Systems 7 22-09-2008 14:38
Life expectancy of items Randall General Sailing Forum 1 14-04-2008 21:31
Solar panels - life expectancy Talbot Construction, Maintenance & Refit 3 16-11-2005 17:52



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 05:10.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.