Firefly Battery Question?

[Stu Jackson]

Sorry to hear, but thanks for answering my questions. Do you attribute the heavy gassing to bad batteries?

[BAD ORCA]

Originally Posted by Stu Jackson

Sorry to hear, but thanks for answering my questions. Do you attribute the heavy gassing to bad batteries?

I honestly dont know. that was my initial gut reaction because i know so many boats have house batteries in the living space and i never hear anyone complain of off-gassing problems. i couldnt fathom it was normal, but it was my first set of 'real' deep cycle batteries i had owned so i wasn't sure what to expect from them.

oh well lesson learned, now im a little bit more knowledgeable.

[Scubaseas]

Heavy gassing and bubbling under heavy discharge/load like when the starter is engaged are classic symptoms of a bad cell. Quick way to check for bad cell is look at the cells while cranking the engine, if you have one that bubbles it's a soon to be dead cell.

A cell on it's way out will make the regulator over charge the battery also as it reads "let's charge" when it shouldn't. Having to add water more frequently to a FLA is another sign it's on it's way out.

[sailorboy1]

Consider doing an equalization.

I undercharged a bank of T105s on my boat that that lved on a mooring with the frig on that got mostly only used on weekends. They lasted 4 years. On other hand the replacements for those only made it 3 years because the solar went out while i was gone a week, but still made it for 4 months after the problem.

While trojan says 14.9v at absorption i found that really makes them gas, but 14.8 didn't as much and if you held long enough still got them charged

Only had my $$$$ firefly batteries a year, so way too early to know if they really are better

[BAD ORCA]

Originally Posted by Scubaseas

Heavy gassing and bubbling under heavy discharge/load like when the starter is engaged are classic symptoms of a bad cell. Quick way to check for bad cell is look at the cells while cranking the engine, if you have one that bubbles it's a soon to be dead cell.

A cell on it's way out will make the regulator over charge the battery also as it reads "let's charge" when it shouldn't. Having to add water more frequently to a FLA is another sign it's on it's way out.

interesting. there was one cell that bubbled vigorously when voltage approached the low 14's during charging. it never really boiled off any water though. i never had to add liquid. i think when i got them thay were a little too full. they never really saw heavy loads so i cant comment on that, but i remember the first couple of times i charged them there was that rotten egg smell. i lowered the charge voltage a bit and it went away. in hindsight that may not have helped anything.

[BAD ORCA]

Originally Posted by sailorboy1

Consider doing an equalization.

I undercharged a bank of T105s on my boat that that lved on a mooring with the frig on that got mostly only used on weekends. They lasted 4 years. On other hand the replacements for those only made it 3 years because the solar went out while i was gone a week, but still made it for 4 months after the problem.

While trojan says 14.9v at absorption i found that really makes them gas, but 14.8 didn't as much and if you held long enough still got them charged

Only had my $$$$ firefly batteries a year, so way too early to know if they really are better

yeah i was considering doing that also. honestly though i feel like im done with open flooded batteries. im considering just using Fireflys from here on out. hopefully by the time they die lithium will be eassier to install and ill be ready to make the switch.

[Scubaseas]

Take a look at these: https://rebelbatteries.com/product/l...phate-battery/
They meet the ABYC TE 13 recommendations and look to be well made. Might be an option for you. You can put up to 4 of them in parallel but you would need to address changing how your alternator charges and other things to get LiFePo4 working for you. Like a B2B charger or a lithium designed regulator but the regulators run $300 to $900. But then saying LiFePo4 here is like saying "Anchor" or "Gun" or maybe now "toast"

Sounds like you may have either overcharged and damaged a cell on the Trojans or gotten one with a bad cell. Or a cell was/is on the way out. One of the best ways to test a FLA is with the old style carbon pile tester, not the newer capacitive discharge testers. or use the starter which can be 100A to 300amps draw and watch for bubbles or rapid voltage drop.

Equalizing the Trojans that you have may work. I'd try it before buying anything. And turn down the top voltage so they don't boil off.

Do a capacity test with a constant load vs time to find out if they have life left or not. 20 amp discharge over time.

I looked into FLA, AGM, GEL and LiFePo4 as I just changed my house bank and had it ruined by someone leaving stuff on repeatedly which killed the batteries. If I had a battery protector/disconnect maybe I would not have just trashed $1800 in new AGM GC batteries but such is Covid and not being able to get to the boat. BUT if you are going to cycle the fireflys beyond the 50% SOC look and see how short the life span gets. At 80% SOC discharge rates the life span is about the same as that of a FLA at 50% SOC cycles and the cost benefit/life span disappears. They do look good on paper but for me I bit the bullet and will go over to LiFePo4.

https://oceanplanetenergy.com/wp-con...compressed.pdf

[ranger58sb]

Originally Posted by BAD ORCA

yeah i was considering doing that also. honestly though i feel like im done with open flooded batteries. im considering just using Fireflys from here on out. hopefully by the time they die lithium will be eassier to install and ill be ready to make the switch.

There are less expensive AGMs, if all you're after is minimum off-gassing.

Odyssey, Lifeline, I've read also Northstar, maybe one or two others, in the premium category but still significantly lower $$$ than Firefly I think.

Then there are the middle-of-the-road versions from others, at lower cost; might not last as long but still may be an OK solution for you.

That's not meant to critique Firefly, just mentioning options.

-Chris

[sailorboy1]

Originally Posted by ranger42c

There are less expensive AGMs, if all you're after is minimum off-gassing.



That's not meant to critique Firefly, just mentioning options.

-Chris

That's true. If it is only a gassing issue preventing getting fully charged FireFly is an expensive route. The only reason I went to FireFly was because they didn't need to get fully charged all the time. Otherwise I would still have my T105s.

[BAD ORCA]

Thanks guys. No actually my choice for Firefly's is their ability to go longer periods at a partial state of charge without damage. The fact that they are sealed and wont generally offgas is just a bonus.

When i actually get to building my new house bank later this year, it will be several Firefly's under the quarter berth so off-gassing would have been an issue with any open FLA.

And considering my use/charge habits im not sure regular agm's would survive as im under the impression they like to be fully charged right after use or may become damaged.

[BAD ORCA]

Originally Posted by Scubaseas

Take a look at these: https://rebelbatteries.com/product/l...phate-battery/
They meet the ABYC TE 13 recommendations and look to be well made. Might be an option for you....[/URL]

Thanks for all that. some good info. was interesting video when he cut them open. they looked pretty well made.

[Sohum]

Restorative charge process, how many of you are holding float voltage for 24hrs? And if so how are you achieving it? How often? Thx.

To perform the restoration charge: charge the G31 to 14.4V or the 4V/450AH to 4.8V and continue to charge until the current drops to 0.5 A on the G31 or 3A on a 4V/450AH and apply a float charge of 13.5V(4.5V for 4V model) for 24 hours. Fully discharge the battery to 10.5V (G31) or 3.5V (4V/450AH), and then repeat the same charge cycle.

[BAD ORCA]

Originally Posted by Sohum

Restorative charge process, how many of you are holding float voltage for 24hrs? And if so how are you achieving it? How often? Thx.

To perform the restoration charge: charge the G31 to 14.4V or the 4V/450AH to 4.8V and continue to charge until the current drops to 0.5 A on the G31 or 3A on a 4V/450AH and apply a float charge of 13.5V(4.5V for 4V model) for 24 hours. Fully discharge the battery to 10.5V (G31) or 3.5V (4V/450AH), and then repeat the same charge cycle.

I havn't had to do this restorative charge yet. I think ill do it in a few months as the Firefly's are doing quite well under my sporadic use/charge regimen. I havn't really noticed any walk down yet after a couple of moths of use.

I have a Sterling Pro Ultra charger and when its in the PS mode I beleive it will stay in float at the voltage i set it at, and will stay on until its turned off at the breaker. It also has a power savings mode (BC mode) which can be turned off by putting it in 'power supply mode', which will turn the charger off automatically after either being in float for a certain amount of time or once the batteries reach a certain voltage. Im not sure exactly what triggers it.