Any two years reviews for Firefly batteries?

[john61ct]

Well they're as good as any AGM setting aside FF unique advantages.

But FLA on the one hand and LFP on the other each have extreme Pro's in their favor, whereas AGM fits the middle "only if you must" arena.

[ranger58sb]

Originally Posted by missourisailor

Useful capacity of the FF is about 240Ah compared to 187Ah for the Life Lines. So FF give you more useful Ah in the same space.

I won't tell you what to do. But I will tell you that you won't be disappointed with the FF's.

Yep, not to worry, I understand. And thanks for info. Mostly my decision will probably come down to a) the extra cost for that extra 52.5* Ah of capacity, calculated over the potential life of the new bank, and b) FF availability if I decide to lean slightly toward that solution.

* Assumes routine FF drawdown to 80% SOC compared to 50% SOC for a Lifeline bank. Analysis should also take into account that we rarely draw down batteries even to 50% anyway, just from our typical use/charging regime.

-Chris

[missourisailor]

Originally Posted by ranger42c

.....and b) FF availability if I decide to lean slightly toward that solution.


-Chris

Availability (or more correctly their LACK of availability) is truly FF's greatest downfall. And is a major point which must be factored in when considering their deployment.


Pls keep me posted on your decision.

[sirlandsalot]

Originally Posted by boatman12

I would be interested in this as well. Also, would there be problem with a non-Firefly battery as a start battery since they would be effectively in parallel when charging from the engine alternator.

Hi Boatman, I am digging through threads and this particular post is exactly what I am looking for. Can you tell me what you learned? I am trying to find out if my alternators will hurt the firefly and can I run a sealed bar for the start.

Cheers
David

[mlydon]

I use a balmar 12v to 12v charger (duo charge), so you can set the start battery chemistry as you please, while your alternator charges house as appropriate.

Ultimately cheaper than buying an extra firefly for stater duty....

Matt

[RickG]

If I used a standard dedicated start battery I would go with a 12V DC to DC charger. Balmar and Sterling Power make good ones.

It's overkill, but I use a Firefly G31 as an isolatable start battery. It spends almost all its time combined with the house bank. The negative for the start battery runs through the Victron shunt as well. Our Balmar 110amp alternator runs through a Balmar MC-614 external regulator. It's nice to have a single battery chemistry and charge profile.

We live on the hook in the Caribbean full-time and the batteries are at 84% most mornings and at 100% by early afternoon. Our batteries have never gotten below 12.3V or 50% SOC. We have a Honda generator as backup for charging. If we were going to take the bank below 50% I would isolate the start battery. There is some risk at not being able to start the engine with this configuration, but I get that extra capacity and don't have dead weight in the 99.8% of the time when we are not starting the engine. The generator and solar are backups.

Our Firefly Group 31s are just zero hassle and completely reliable. Depending on the daily temperature, we are down 130ah - 170ah in the morning; the range is driven by the freezer/refrigerator run time. We have a Victron 3kva inverter/charger that stays on and we run a lot of electronics; I work from the boat full-time doing remote IT work.

Cheers, RickG

[toolarts]

Originally Posted by phantomracer

2 full seasons on 2 firefly batteries in parallel.

So far so good they've been excellent. . . .
`

The directions come with information about charging but it's pretty close to a lead acid battery. If you have a Balmar style alternator that is externally regulated you may want to check the charge voltage to ensure it complies.
. . ..

I have three, have had them for 2.5 years. They are still operating like new batteries. The above quote, however, is wrong, sorry. They do NOT charge like a lead acid battery. When nearly charged, you can damage them by giving them full 14.8 volts of charge. 14.8 can only be applied during bulk charge. A standard alternator like the Hitachi supplied with most older Yanmar engines can damage the Firefly.

After installing the Firefly's, I installed a Balmar 100 amp alternator and the MC-614 Charge Regulator. The program for the MC 614 is actually on the Firefly website. I compared the built-in programs on the Balmar with the Firefly suggested program, and the one that comes closest is actually the Lithium Ion program on the MC-614. Since I am too lazy to put in an entirely new program using a magnetic screwdriver and a one-button menu, I use this one and it works pretty well--does not hit the full battery with 14.8 volts, which is what I care about.

My current marina is undergoing some reconstruction, and they shut off the power for my dock and offered me another slip. I am so lazy I haven't moved to the other slip, 3 months now. No power, no solar panel. Just my Yanmar, my Balmar, and my firefly's. No power problems whatsoever. I run the engine for 1/2 hour every week or so. The rest of the time, I enjoy 12 volt power.

All three fireflys are connected in parallel for 12v, They do everything, fan, lights, heater, engine starting, TV, stereo, etc. No I don't have refrigeration.

Cheers.

[phantomracer]

My point was they are effectively LA batteries. You can charge them with the equipment on most boats with little to no modification. Something you can not do with Lithium batteries.

Also use the 614 and a custom program.

I would suggest using an externally regulated alternator

I can't comment on how they would charge with standard alternators. Not an expert.

In any case, they are doing stunningly better than my (more expensive) LA batteries ever did! More amps, fast charging, no worrying about PSOC!

[RickG]

Originally Posted by toolarts

My current marina is undergoing some reconstruction, and they shut off the power for my dock and offered me another slip. I am so lazy I haven't moved to the other slip, 3 months now. No power, no solar panel. Just my Yanmar, my Balmar, and my firefly's. No power problems whatsoever. I run the engine for 1/2 hour every week or so. The rest of the time, I enjoy 12 volt power.

All three fireflys are connected in parallel for 12v, They do everything, fan, lights, heater, engine starting, TV, stereo, etc. No I don't have refrigeration.

Cheers.

No refrigeration makes a huge difference. Our power budget in the Caribbean for a single compressor freezer with spill over refrigerator is 120 amp hours per day. On a sunny day we see over 30 amps from solar going into the batteries mid-day.

Cheers, RickG

[FAST FRED]

"We live on the hook in the Caribbean full-time and the batteries are at 84% most mornings and at 100% by early afternoon. Our batteries have never gotten below 12.3V or 50% SOC."

If that is the normal batt profile, why did you spend extra for FF?

WLA would seem to work as well at 1/2 the cost.

[Pegu Club]

Originally Posted by FAST FRED

"We live on the hook in the Caribbean full-time and the batteries are at 84% most mornings and at 100% by early afternoon. Our batteries have never gotten below 12.3V or 50% SOC."

If that is the normal batt profile, why did you spend extra for FF?

WLA would seem to work as well at 1/2 the cost.

Just a guess on my behalf, we don’t draw our firefly batteries down very far either, but we can at need without damaging the batteries. It is in a sense like having a reserve amp supply. That is part of the reason we have FF batteries, and may very well be the same for other users. That they don’t require anything special in installation or charging is a plus as to maintenance concerns. With two one hundred watt solar panels or the 70 amp alternator they charge quickly and offer more usable amps at need, and PSOC issues are less of a concern. We are going on two years of full time cruising use, so far so good. I would recommend them.

Fair winds,

[a64pilot]

Not sure where 14.8 is coming from, charge voltage is 14.4 and float 13.4.
Pretty much exactly the same as Lifeline, within .1V anyway
Link to manual
https://oceanplanetenergy.com/wp-con...al-G31-L15.pdf

[a64pilot]

Anyone using the L15+’s?

[phantomracer]

Originally Posted by FAST FRED

"We live on the hook in the Caribbean full-time and the batteries are at 84% most mornings and at 100% by early afternoon. Our batteries have never gotten below 12.3V or 50% SOC."

If that is the normal batt profile, why did you spend extra for FF?

WLA would seem to work as well at 1/2 the cost.

True, OTOH, since the FF don't mind being discharged deeper, you can get away with fewer batteries if you want to get the same number of amps out. If , for example, they had 3 FLA batteries (assuming same size/amp hr), they could, theoretically, get 2 FF and just discharge them deeper (which they don't seem to do )

[RickG]

Originally Posted by FAST FRED

"We live on the hook in the Caribbean full-time and the batteries are at 84% most mornings and at 100% by early afternoon. Our batteries have never gotten below 12.3V or 50% SOC."

If that is the normal batt profile, why did you spend extra for FF?

WLA would seem to work as well at 1/2 the cost.

The key here is that charge acceptance is high, so we get a lot more out of our solar than with FLA or AGM. We had FLAs before, but adding more capacity meant putting a battery box under a bunk; watering and outgassing aren't great in that space. We had no other options of another battery box.

We can go three days with no sun and not have to run the generator. We have four of the Fireflys in a battery box under a bunk that would be a hassle to water.

We are adding an Engel freezer and it will be interesting to see the impact on our power budget.

Cheers, RickG