Cruisers Forum
 


Join CruisersForum Today

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 22-07-2017, 06:44   #1
Registered User
 
Training Wheels's Avatar

Join Date: Aug 2014
Location: Left coast.
Posts: 1,095
Gel Versus Firefly Carbon Foam

For you battery gurus, how do gel and Firefly batteries compare? Which are the best bang for the buck? Seems they have similar attributes, but which do better in a partial SOC, ands which can do more deep discharges?
__________________

Training Wheels is offline   Reply With Quote
Old 22-07-2017, 07:11   #2
Registered User

Join Date: Jan 2017
Posts: 11,733
Re: Gel Versus Firefly Carbon Foam

Gel are easily damaged by heat and overcharging. Do not hold up well in hot engine rooms, cannot be fast charged by ordinary fast chargers, require much slower charging rates.

Yes they can last a long time when cared for properly, and do withstand PSOC abuse.

Need actual advice on Gel batteries for my boat


Firefly Oasis are newer, thus less widely proven, more robust for high-amp charging, ​14.2-14.6V setpoint, 14.4 is ideal, 13.2 float, up to 13.5V maximum, but 13.2V is still recommended for longevity.

Designed for PSOC and down to 80% DoD, easy periodic "capacity reset" protocol is unique.

My preference would be Firefly, if the $500 per 100AH weren't a sticking point.

Also waitlisted these days.
__________________

john61ct is offline   Reply With Quote
Old 22-07-2017, 07:15   #3
Registered User

Join Date: Jul 2013
Location: Refit in Port Townsend, WA
Boat: 1984 Slocum 43
Posts: 425
Re: Gel Versus Firefly Carbon Foam

I went with Firefly and no regrets. However, as john61ct said, it will take a while to get them nowadays. They're selling them faster than they can make them until the new production line is up and running.
Mycroft is offline   Reply With Quote
Old 22-07-2017, 07:25   #4
Registered User

Join Date: Jan 2017
Posts: 11,733
Re: Gel Versus Firefly Carbon Foam

No need to pay anything until they become available, first come first served on a waitlist.
john61ct is offline   Reply With Quote
Old 22-07-2017, 17:02   #5
Registered User
 
CarinaPDX's Avatar

Join Date: Jan 2010
Location: Portland, Oregon, USA
Boat: 31' Cape George Cutter
Posts: 2,251
Re: Gel Versus Firefly Carbon Foam

Quote:
Originally Posted by john61ct View Post
Gel are easily damaged by heat and overcharging. Do not hold up well in hot engine rooms, cannot be fast charged by ordinary fast chargers, require much slower charging rates.
Please provide references - this does not agree with the web pages I just looked at, my research when I first bought gel batteries, or my personal experiences over the last 25 years of cruising and living aboard. (See Victron's datasheet here: https://www.victronenergy.com/upload...tteries-EN.pdf) Also go to batteryuniversity.com

Specifically, I have used gels (Sonnenschein) in the Caribbean and the Med in very hot weather to no disadvantage. They are located in a locker beside the engine compartment - batteries should NEVER be located in the engine spaces, unless you want to kill them (all lead designs).

Most marine battery chargers do have a "gel" setting, for the lower charge voltages required. Or they can be adjusted to suit. It is mostly a matter of knowing to do it. These days being able to adjust the voltages should be a given; the features to look for are remote temperature sense of the batteries, so as to not charge them too quickly and cause gassing (more of an issue with AGMs drying out), and remote temperature sense of the alternator so as to not burn it out by trying to charge a large battery bank from deep discharge. I see Victron uses the time in bulk charge to adjust the time in absorption charge so as to not keep a high voltage on too long for batteries that are already nearly full. It is well worth investing in a smart charger for the longer service life of the batteries.

It is true that AGM batteries have an even lower internal resistance than gels, which themselves have much lower resistance than flooded. So AGM can charge a bit faster (not "much" faster), and maintain a bit higher voltage in use, than gels, but the differences are small compared with flooded - which take much longer to charge and sag voltage more in use than either. One reason I went with gels is for the stiffer voltage, as my ham radio at the time didn't handle the flooded voltage sag well at all (and these were Rolls flooded batteries).

Both of these batteries are valve-regulated lead acid (VRLA) and so are far more similar to one another than to flooded batteries. The gels are more expensive and have a longer, to much longer (depending on model), service life than AGMs. This is in part due to the fact that the separators in gel batteries are thermal conductors and can thus transfer heat out of the battery better than the thermally non-conductive ones used in AGMs. Gels are more robust, and can handle abuse (other than extreme vibration) a bit better than AGMs - and contrary to earlier statements perform better than AGMs at high temperatures. They do require capping the charge voltage at a lower point than for AGMs and flooded, at least for some products. AGMs are widely available, less expensive, capable of putting out a higher start current, more vibration resistant (for those with cigarette boats), and work well with chargers using a profile for flooded batteries. Otherwise the gels win.

It seems to me a lot of the confusion is from the advertising/PR that AGM manufacturers put out, which quote the large improvements over flooded along with vague statements about gels.

It should go without saying that we are only talking about quality batteries here; cheap batteries don't belong on a cruising boat.

Greg
CarinaPDX is offline   Reply With Quote
Old 22-07-2017, 17:42   #6
Registered User

Join Date: Sep 2014
Posts: 86
Re: Gel Versus Firefly Carbon Foam

Firefly Oasis carbon foam batteries . Waiting for them due to demand says it all ! Google them and see the reason why they are a game changer !��
navy davy is offline   Reply With Quote
Old 22-07-2017, 18:49   #7
Registered User

Join Date: Jan 2017
Posts: 11,733
Re: Gel Versus Firefly Carbon Foam

Quote:
Originally Posted by CarinaPDX View Post
I have used gels (Sonnenschein)
...
It should go without saying that we are only talking about quality batteries here; cheap batteries don't belong on a cruising boat.
Perhaps specific make, relatively expensive gels have been in recent years re-engineered to overcome their susceptibility to heat damage?

But if those cost even more than the Fireflies, then you're approaching LFP territory. . .


Quote:
Originally Posted by CarinaPDX View Post
lower charge voltages required.
...
It is true that AGM batteries have an even lower internal resistance than gels, which themselves have much lower resistance than flooded. So AGM can charge a bit faster (not "much" faster)
I was talking amps (CAR specs), appropriate voltage assumed.

I did some googling on Sonnenschein, it seems their "dryfit" line is made by/sold as Deka*"Gel-Tech"?

And that very high amp charge rates are fine.

So now I'm not sure if this line is an exception, or the many threads I've read with these caveats are misinformed, mea culpa. . .
john61ct is offline   Reply With Quote
Old 22-07-2017, 20:52   #8
Registered User
 
CarinaPDX's Avatar

Join Date: Jan 2010
Location: Portland, Oregon, USA
Boat: 31' Cape George Cutter
Posts: 2,251
Re: Gel Versus Firefly Carbon Foam

While gels have been around a long time, it took Sonnenschein to get them to work reliably. IIRC they started to show up around 1990 in marine circles; I got my first in 1995. It seems one of the major issues with gels was a tendency over time for the gel to develop cracks, which of course blocked current flow, and Sonnenschein solved this. I think they had a strong patent position as a result. Those patents should have expired a long time ago, but of course that doesn't cover trade secrets and manufacturing expertise.

In the US Sonnenschein sells the Dryfit Prevailer, apparently through East Penn Manufacturing. These have DIN-sized cases (I used the DF180). East Penn sells their own gel batteries, the Deka line, in BCI sizes (which are sold by Sonnenschein in Europe). I use the Group 31 size. The West Marine Seagel batteries were made by Sonnenschein, but today the name has changed and they are made by East Penn. I believe this relationship between East Penn and Sonnenschein includes technology transfer, but I haven't found any public statement. These brands are the only ones I would trust with gel batteries; other high volume brands do not have a stellar record. But these are the gels that most marine electrical outlets handle.

East Penn now makes a very high temp gel battery, the Fahrenheit Deka. I don't think we need batteries that can comfortably operate at 60ļC, but the technology is there. OTOH if anyone has a boat with the batteries in the engine space then maybe so. Or simply relocate the batteries...

One thing I forgot to mention: AGMs tend to lose capacity linearly over time; gels tend to perform about the same over their lifetime, then fall off rapidly. It is pretty obvious when EOL appears.

Firefly batteries? They certainly sound good on paper. It would be nice to have more experience out there before buying. They cost about the same as gels, and claim to be longer-lived and have lower internal resistance. Perhaps if they are available when my batteries die soon. OTOH either way I suspect I will swallow the hook before the next set of batteries dies.

Greg
CarinaPDX is offline   Reply With Quote
Old 24-07-2017, 07:01   #9
Sponsoring Vendor
 
OceanPlanet's Avatar

Community Sponsor

Join Date: May 2009
Location: Woolwich, Maine
Boat: Mull 42-cold molded NZ 1970
Posts: 452
Send a message via Skype™ to OceanPlanet
Re: Gel Versus Firefly Carbon Foam

Good gel batteries have really been underrated, for years now. Of course this largely has to do with all the marketing behind the various AGM brands...

Even the inventor of the Firefly carbon-foam technology has told me that good gels are very underrated. As I understand it, one potential vulnerability of gel is shock resistance. A good shock can knock the gelled electrolyte off of the plates, which is pretty much the end of the battery. And yes, the CAR is less than AGM, however CAR if often an over-rated value due to the reality that most boats don't have the ability to charge anywhere near their battery's CAR anyhow...

FWIW, I raced twice around the world on OceanPlanet, with the same set of Gel batteries (long before Li or carbon-foam batteries existed)...
__________________
Twice around was enough for me...
Now I just help others prep for ocean trips...
www.oceanplanetenergy.com
OceanPlanet is offline   Reply With Quote
Old 24-07-2017, 08:07   #10
Registered User
 
Colin A's Avatar

Join Date: Mar 2013
Location: East of the river CT
Boat: Oday Mariner 19 , Four Winns Marquis 16 OB, Kingfisher III
Posts: 644
Send a message via Skype™ to Colin A
Re: Gel Versus Firefly Carbon Foam

Quote:
Originally Posted by OceanPlanet View Post
Good gel batteries have really been underrated, for years now. Of course this largely has to do with all the marketing behind the various AGM brands...

Even the inventor of the Firefly carbon-foam technology has told me that good gels are very underrated. As I understand it, one potential vulnerability of gel is shock resistance. A good shock can knock the gelled electrolyte off of the plates, which is pretty much the end of the battery. And yes, the CAR is less than AGM, however CAR if often an over-rated value due to the reality that most boats don't have the ability to charge anywhere near their battery's CAR anyhow...

FWIW, I raced twice around the world on OceanPlanet, with the same set of Gel batteries (long before Li or carbon-foam batteries existed)...
Gels are excellent house batteries. I have found them perfect for leaving on a slow solar charge while hanging on the mooring. There are lots of bad stories about gel mostly due to people not setting up the charging correctly. As Bruce notes CAR may or may not be important to you. For me running mostly on a small solar array it matters very little.
__________________
mysite: Colinism.com
Colin A is offline   Reply With Quote
Old 24-07-2017, 08:42   #11
Registered User

Join Date: Jan 2017
Posts: 11,733
Re: Gel Versus Firefly Carbon Foam

Yes high CAR is only important for hit-and-run shore charging, or minimizing dino-juice run-time when that's the only reason it's running.

A very large bank with limited solar is greatly assisted by a big-amp charge in the morning to get up to say 80% SoC.

High CAR may mean that's done in under an hour rather than three or more.

Then the PV has all day to finish the long tail, can get to 100% every day, make that bank last **many** years longer.

But yes, a scenario with a specific list of conditions, otherwise higher CAR not important.
john61ct is offline   Reply With Quote
Old 24-07-2017, 09:01   #12
Registered User
 
Training Wheels's Avatar

Join Date: Aug 2014
Location: Left coast.
Posts: 1,095
Re: Gel Versus Firefly Carbon Foam

Thank you for the replies. Do gels handle PSOC as well as the Firefly's, say if they are only getting fully charged once a week?
Training Wheels is offline   Reply With Quote
Old 24-07-2017, 12:21   #13
Registered User

Join Date: Jan 2017
Posts: 11,733
Re: Gel Versus Firefly Carbon Foam

That's an open question, but I'm going with No, fact that Firefly is specifically designed for PSOC, and Maine Sail et al have confirmed the magic works.

Gel happens to tolerate PSOC a bit better than average AGMs, is I think the best can be said about them. I haven't seen any structured testing reports.
john61ct is offline   Reply With Quote
Old 24-07-2017, 13:25   #14
txg
Registered User

Join Date: Oct 2014
Location: Berlin - Germany
Boat: Dufour 35
Posts: 195
Re: Gel Versus Firefly Carbon Foam

Does anyone have experience with the Trojan RE batteries? They also seem to have some kind of carbon stuff and are designed for PSOC cycling. The L16RE-B would be very interesting for us because it fits 370Ah in the space that currently holds only two G31 with 220Ah as we have the height for the L16.

Also two of them at 370Ah are much cheaper than three of the Firefly at only 330Ah. And they seem to be easily available.
txg is online now   Reply With Quote
Old 24-07-2017, 13:25   #15
Registered User
 
Colin A's Avatar

Join Date: Mar 2013
Location: East of the river CT
Boat: Oday Mariner 19 , Four Winns Marquis 16 OB, Kingfisher III
Posts: 644
Send a message via Skype™ to Colin A
Re: Gel Versus Firefly Carbon Foam

Quote:
Originally Posted by john61ct View Post
That's an open question, but I'm going with No, fact that Firefly is specifically designed for PSOC, and Maine Sail et al have confirmed the magic works.

Gel happens to tolerate PSOC a bit better than average AGMs, is I think the best can be said about them. I haven't seen any structured testing reports.
In general based on my experience with them Gel tend to have more cycles in a house bank then AGM and deal with PSOC better. Looking at Trojan and DEKA for instance they both appear to have significant cycle life increases.
__________________

__________________
mysite: Colinism.com
Colin A is offline   Reply With Quote
Reply

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
Firefly Oasis Carbon Foam AGM Batteries epiic Electrical: Batteries, Generators & Solar 94 25-12-2018 10:23
Firefly carbon admiralslater Marine Electronics 1 11-10-2015 20:15
Firefly Carbon Foam AGM batteries? hellosailor Electrical: Batteries, Generators & Solar 1 29-08-2015 17:09
Boston Whaler versus Albury versus ??? Magor Powered Boats 3 26-02-2014 11:43
To Gel or Not to Gel - That Is the Question Fishman_Tx Construction, Maintenance & Refit 137 21-12-2009 15:49



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 03:17.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.