Agm batteries....who's the best or worst?

[blue otter]

This has probably been asked but I did one see it, so thought I would ask. I'm getting ready to replace the house bank and want. I want to squeeze as many amps as I can into the equation.

I don't want to start a food fight on the subject but what are the best batteries or what are the brands to stay away from.....my impressions are the lifeline and Victron are good.

Also while I have read as much as I can find about Firefly batteries, does anyone have any supporting evidence to support the limited info?

[Paul L]

I've had good service from Rolls and Bottom AGMs. Terrible service from Northstar.

[Paul Elliott]

My Lifeline AGM 8D bank was commissioned in 2002 and it's still going strong. In fairness, it spends most of the time on solar trickle-charge. Every year or two we go on a two-month excursion where we take the bank down to 50% or so every couple of days, and recharge with solar and alternator. We also have the occasional multi-day trip with heavy battery use, and I do an annual 24-hour load test. The capacity may have dropped a little, but not much in these 14 years of irregular use, so I'm happy with the Lifelines.

[Kenomac]

Paul,

I was also planning on starting a similar thread today. Next season, I need to replace the battery bank. Which to choose lead acid, AGM or Lithium ion? Does the AGM battery bank charge up any faster than lead acid using a 10kw generator?

Most of the power coming from our generator just seems to be wasted since it takes so long to charge the batteries. Solar isn't really a viable option in our case, since switching to lithium would cost about the same all inclusive. Then the generator will charge those up quickly.

Ken

[Sandero]

Our 8D AGM are on a solar "trickle charge" all week long when we are not aboard... and they are always topped up... 12.8.... We don't take them down much because we use the high output alt a few times a day when leaving or entering the anchorage. They are 2012 UNIVSERSAL 250AH:

[Paul L]

Originally Posted by Paul L

I've had good service from Rolls and Bottom AGMs. Terrible service from Northstar.

Stupid spell check. That is Rolls and Victron

[tenchiki]

There's a new process out there "Carbon Foam AGM" the Firefly Battery. They haven't been out long enough to determine a real lifetime, but initial testing is very impressive. Practical Sailor and Nigel Calder have good things to say about them.

Disclaimer: I won one in a contest on this site, though with my current use case, I'd probably be fine with the car battery that the boat came with...

[ranger58sb]

Originally Posted by blue otter

I don't want to start a food fight on the subject but what are the best batteries or what are the brands to stay away from.....my impressions are the lifeline and Victron are good.

Also while I have read as much as I can find about Firefly batteries, does anyone have any supporting evidence to support the limited info?

We've had good service with Odyssey PC-2150 (Group 31) AGM. Oldest bank is midway through it's 11th season. Our batteries are usually on the charger from shorepower, or charged via genset 2x/day, always recharged soon after extra heavy use.

An independent Firefly owner has posted a very useful "after 1 year" review somewhere, either here or on trawlerforum.com.

FYI, Bruce Schwab (Firefly guy) is a member here and on TF.

If you want to improve your deep cycling capabillity with 6V AGM golf cart batteries instead of 12V AGM, Lifeline makes those. I think Trojan does now, too, and Trojan has a pretty good reputation for FLA golf cart batteries... so that might apply to their AGM versions.

-Chris

[gamayun]

Originally Posted by ranger42c

If you want to improve your deep cycling capabillity with 6V AGM golf cart batteries instead of 12V AGM, Lifeline makes those. I think Trojan does now, too, and Trojan has a pretty good reputation for FLA golf cart batteries... so that might apply to their AGM versions.

-Chris

Can you explain how the deep cycling is improved by using 6v rather than 12v? I have 2 sets of 6v Lifeline AGMs in series because of space limitations.

[ranger58sb]

Originally Posted by gamayun

Can you explain how the deep cycling is improved by using 6v rather than 12v? I have 2 sets of 6v Lifeline AGMs in series because of space limitations.

There are a boatload of threads about it, with more complete description by experts like MaineSail (and see his own Compass Marine site)...

But the short version is that 6V golf cart batteries are said to be truly deep cycling capable -- by design, with thicker plates -- whereas 12V "deep cycle" batteries are said to more often be "dual purpose" with a "deep cycle" label attached.

-Chris

[Mikado]

Originally Posted by blue otter

This has probably been asked but I did one see it, so thought I would ask. I'm getting ready to replace the house bank and want. I want to squeeze as many amps as I can into the equation.

I don't want to start a food fight on the subject but what are the best batteries or what are the brands to stay away from.....my impressions are the lifeline and Victron are good.

Also while I have read as much as I can find about Firefly batteries, does anyone have any supporting evidence to support the limited info?

I had (3) LifeLine 8D AGM batteries on my boat for three years when two of them (house batteries) were taken out by a lightning strike. The one bow thruster battery was fine.

Although I was really happy with the LifeLines, for budgetary reasons I switched to Deka when I replaced. I did a lot of research and the Deka meet or exceed all the LifeLine specs and were about 40% cheaper.

Time will tell if I made a good decision.

[johnleeknot2bus]

A couple of years ago, I bought 5 agm batteries from West Marine (West Marine batteries). 3 went bad in about 13 months. West Marine said tough luck, no help. Bought 5 wet cells from NAPA, so far, so good.

[Akapeterc]

I just replaced my six Trojan 6 V batteries with six fullRiver 6 V batteries 250 amp hour each. I wanted as much amp hours as possible and this seemed my best option

[Captain Puget]

I suggest you look at Firefly carbon foam batteries
Firefly International Energy Co | Innovation takes Wings!

[waterman46]

I just replaced my 12 year old 4D Lifelines with new Lifelines. Cheapest I found was at sepbatteries.com.

I seriously considered and investigated wet cells (again) and everytime I come to the same conclusion: I don't want and cannot be a babysitter for my batteries, I want quicker charging, and above all I want the best safety (no gas, no spillage). This favors AGM.

I think the evidence given in this thread previously, shows that there are some AGM's out there that are less robust than Lifeline and I would stay away from those.