FireFly Battery Long Term Users - Speakup

[Britishsea]

I had a two G31 firefly bank with a balmar 110 amp alternator. I purchased them in 2019. The first battery completely failed the start of the second season. It had a capacity of 20ah at that time, even after several restoration charges. It was properly charged over the winter using a Blue Sea P12 charger.

I made a warranty claim and had a very difficult time trying to get it resolved.

Being in parallel with the bad battery, my second firefly also had diminished capacity (80 aH) back when I made the warranty claim, but understandably it did not qualify for a claim at that capacity level. So with some help from this forum, i did some restoration charges and put it in the bank in parallel with the replacement battery (all this is documented in these forums in a thread titled Re: Firefly Oasis : 2 years old and dead - i did not start the thread).

I took this second Firefly 2019 battery off the boat last week to do a restoration charge. It had a 42ah capacity when tested. I recharged and discharged 4 times. No change. It was within 1ah each time.

Firefly had some serious QC problems, and unless I knew for sure they were resolved, I would be wary.

[Uncle Bob]

Originally Posted by Britishsea

I had a two G31 firefly bank with a balmar 110 amp alternator. I purchased them in 2019. The first battery completely failed the start of the second season. It had a capacity of 20ah at that time, even after several restoration charges. It was properly charged over the winter using a Blue Sea P12 charger.

I made a warranty claim and had a very difficult time trying to get it resolved.

Being in parallel with the bad battery, my second firefly also had diminished capacity (80 aH) back when I made the warranty claim, but understandably it did not qualify for a claim at that capacity level. So with some help from this forum, i did some restoration charges and put it in the bank in parallel with the replacement battery (all this is documented in these forums in a thread titled Re: Firefly Oasis : 2 years old and dead - i did not start the thread).

I took this second Firefly 2019 battery off the boat last week to do a restoration charge. It had a 42ah capacity when tested. I recharged and discharged 4 times. No change. It was within 1ah each time.

Firefly had some serious QC problems, and unless I knew for sure they were resolved, I would be wary.

Makes my 6volt golf cart bank look like an absolute bargain, going on 9 years now and while not as good as new, it does everything that I need of it, including running the fridge 24/7.

[Peeew]

I do know that a few years ago there was a big quality control issue when factory was changed. Does anyone know the serial number range that was affected?

[BAD ORCA]

Originally Posted by Britishsea

I had a two G31 firefly bank with a balmar 110 amp alternator. I purchased them in 2019. The first battery completely failed the start of the second season. It had a capacity of 20ah at that time, even after several restoration charges. It was properly charged over the winter using a Blue Sea P12 charger.

I made a warranty claim and had a very difficult time trying to get it resolved.

Being in parallel with the bad battery, my second firefly also had diminished capacity (80 aH) back when I made the warranty claim, but understandably it did not qualify for a claim at that capacity level. So with some help from this forum, i did some restoration charges and put it in the bank in parallel with the replacement battery (all this is documented in these forums in a thread titled Re: Firefly Oasis : 2 years old and dead - i did not start the thread).

I took this second Firefly 2019 battery off the boat last week to do a restoration charge. It had a 42ah capacity when tested. I recharged and discharged 4 times. No change. It was within 1ah each time.

Firefly had some serious QC problems, and unless I knew for sure they were resolved, I would be wary.

Curious where did you buy them? I got my single G31 at Fisheries and suspect I may have a bad one as well. I got mine in 2021 though. Goig to check my serial # this weekend and see if im in the same range.

[Britishsea]

Originally Posted by BAD ORCA

Curious where did you buy them? I got my single G31 at Fisheries and suspect I may have a bad one as well. I got mine in 2021 though. Goig to check my serial # this weekend and see if im in the same range.

I never figured out how their serial numbers worked ( ie , the manufacture date). The replacement battery I received was un-boxed and had been used as demo in that year's boat show. It could easily have the exact same issues; I will have to test it next. At the time it was July and I was just grateful not loosing a boating season limping around on one diminished G31 battery.

I too would like to understand the date ranges impacted by QC as a result of their shift to manufacturing in India. I suspect we will never know.
Really they should do a recall or extend the warranty period for the impacted dates.

Before someone claims I did not overwinter these properly, they well taken care of with the proper temp compensated float voltage applied only part of the time (not all winter).

If firefly have fixed their QC issues and if you can get a good warranty from the vendor with clear terms, I think these could still be a good option as semi lithium replacement. Likely best for full timers who use them hard everyday.

Fisheries have always been great. I'm Canadian, so purchased them locally from the dealer up here. No need to name names.

[crayiii]

It seems like we're having some issues with our bank of six G31's. I was thinking it was because we weren't getting fully charged but I've since ruled that out.

Ours are a bit over one year old and we're seeing a lot more voltage drop than when they were new. We'll be switching back to easily obtainable AGM (lifeline) soon.

I view this as an expensive lesson. Stick with proven LA batteries until we're ready to switch to lithium.

[sailorboy1]

Originally Posted by Britishsea

Before someone claims I did not overwinter these properly, they well taken care of with the proper temp compensated float voltage applied only part of the time (not all winter).

Well what does that mean? When were and how long were they on float as that seems a common failure source in this thread? What/how were your batteries normally used?

[kmacdonald]

LFP is well proven and cheaper if the battery bank is homemade with prismatic cells from China. Actually much cheaper than AGM also.

[sailorboy1]

lets please not change subject

[kmacdonald]

If it looks too good to be true, it probably is. Except the case for LFP of course.

[kmacdonald]

Originally Posted by sailorboy1

I have had my Firefly house battery bank for 1.5 years now with no problems.

But I would like to read long term users stories (yes I know there aren't a lot that would be on the forum). Especially ones who have had them 5+ years AND spent long (months) periods of not pugging into shore power.

Speak up with your story.

Could you share your capacity testing procedure and results?

[sailorboy1]

Originally Posted by kmacdonald

Could you share your capacity testing procedure and results?

Sure

I just go off what the battery monitor says for how many AHs out I am and the voltage. I don't run or spend a bunch time on fancy complicated battery testing to post on a forum. I live in the practical world of cruiser battery use all all I care about is what the voltage is at in my normal use range. If the batteries are -100Ah and the battery monitor says 80%, which they would be based on just doing the math, and the voltage matches why would I not believe the batteries are fine?

Last weekend it was cold down in the Florida Keys so was only -60Ah in morning because of less frig/freezer runtime. It was sunny and the wind had me facing a good direction for my panels. After 2 days of this resulted in my solar dropping into the float, only happens if they have been in absorption for 5 hours or they get down to only 4 amps at absorption, and was first time since mid Oct the batteries were probably fully charged.

My 1.5 year old Fireflies have not been on shore power float even when I was at dock for 5 months. They have spent most of time cycling between 70-95% SOC and based on voltage compared to when new I can not see any capacity change. The only reason I got them is so I don't have to worry about them only getting to 95% PSOC .

[Britishsea]

Originally Posted by sailorboy1

Well what does that mean? When were and how long were they on float as that seems a common failure source in this thread? What/how were your batteries normally used?

We do a lot of off season boating so Winter is only Nov - end of Feb/ March. I live 10 blocks from the boat so there often. I would alternatively turn the charger on and then off throughout the winter. When on, the Blue sea P 12 charger was on "Energy Saver Mode" at 13.4v

*Energy Saver Mode (CEC)
a. After the absorption cycle is completed for all outputs, the charger moves to “rest” mode- not float.
b. As the battery rests, its voltage will drop. If loads are active the voltage will drop more rapidly.
c. When the voltage has dropped to the lower target re-float voltage (12.8V)
d. The charger moves to float voltage and remains in float for a minimum of 4 hours.
e. The charger shuts down and allows the battery to rest again.


I happened to meet with Bruce from Ocean Planet at the Seattle boat show the year I bought these. I described my float procedure ( above) which he opined at the time was ideal for the Firefly.

[sailorboy1]

Doesn't sound like it really was "ideal".

We don't really know as there is so little data out there, which is reason for this thread. But it certainly is looking that the batteries don't like sitting around fully charged and/or being on float.

BTW - I did go back and read the thread you listed.

[phantomracer]

I made some updates to my restoration charge thread for my 6 year old Firefly batteries, as I am actively doing this now.

Got some initial data on the first of the 2 batteries I am going to restore. Using this thread to keep track of my data points as I do this procedure. Feel free to comment on the results or my process.

Firefly restoration charge on my 6 year old Firefly batteries