Originally Posted by deckofficer
I don't agree.
Problem with that graph, as with all "sales tools", is just what is the "leading GEL battery"?????
I tend to prefer to focus on companies who sell GEL, AGM
and Flooded batteries such as Deka/East Penn and Trojan. They have less to lose/gain by stating that GEL batteries off better cycle life than AGM and Trojan and Deka are at least honest about it.
You can disagree with my observations all you want. I come at this from the perspective of a marine
electrician who works on lots of boats not just an n=1 or n=a few.
In the real world of marine
installations I see properly installed & charged GELS consistently outlast all the AGM brands..
I have one customer with a Tartan 4100 that is a 1998 boat. His GEL batteries (East Penn) are still going strong in 2012 at 14 years old. 14 year old AGM's? Never seen them in a boat......
I install Odyssey, Lifeline, Deka, Rolls, Trojan, Full River, US Battery
, Crown, Superior and others and the GELS consistently outlast all the AGM's including the Odyssey & Lifeline batteries. I currently have a bank of four PC2150's showing about 80% of new capacity at just four years old. This bank has an alt capable of 35% of "C" and is properly programmed for the exact profile Odyssey wants. Not bad, but also not GEL...
Odyssey rates their AGM's (laboratory ratings) at 400 cycles to 80% DOD. Deka/East Penn make both AGM and GEL and rate their GEL batteries at more than double the cycle life of their AGM batteries..
What I see, measure and work with in the real world is that GEL batteries outlast AGM easily and consistently time after time. They appear far more tolerant of less than "full charges" than any of the AGM's. The Tartan 4100 only got solar
this year and the boat has been on a mooring
since 2004. The GEL batteries have still survived that abuse.
Interestingly enough I don't see much life cycle difference between Lifeline and the Deka product but the Lifeline CAN be equalized/conditioned making it the better value IMHO. Course this relies on owners who know how & when to do this, which most don't, and who actually do it, which most don't. Often by the time I get called in the batteries are expensive plastic boxes filled scrap metal..
Both AGM & GEL need proper charging
or they will both die ahead of inexpensive flooded cells. I've yet to see many boats that can supply the 40% / "C" in current
that Odyssey wants and many can't even supply the 20% minimum Lifeline wants to see.
That said I do really like the Odyssey AGM's but they need to be installed as a "system" and it can easily push 4k by the time you are done with a new charger
, alt, temp sensors serpentine or dual pulley kit etc. etc. etc......
The average life I see on most AGM's, here in Maine
where boats are mooring
sailed, is 3-4 years. I can greatly extend that with solar
but without it they don't even last as long as inexpensive wet cells..
I will be replacing a three year old bank of Lifeline 4D's on a J-42 in the spring because he has no solar and killed them they were technically dead in September but we are holding off until spring....
The best I can do is share my real world experiences and data (I use Midtronics and Argus analyzers as well as Carbon pile load and 20 hour capacity testing). There are definitely benefits to AGM batteries I just don't find cycle life to be one of them.
Trojan has this to say, and they also sell GEL & AGM batteries:
— "Gel batteries are more suitable for deep cycling applications whereasAGM batteries are more for light cycling and engine-starting applications."