Firefly Oasis : 2 years old and dead

[moseriw]

ok john tks for input but I believed that technology must be backwards compatible. Like i.E. USB. And this is only a part of proper engeneering and notting else.

OK I did not check out other MPPT's but the main statement remains... USB

For my part I have to switch the panels to serial and then it'll be OK BUT

[Peio64]

I don't know these "Firefly" batteries. What I can say is that I moved 4 years ago for lithium batteries with the Elite Power Solution system and that I am fully satisfied.

[Nicholson58]

We installed 6 X 4V = 24 volts L15 450 AH. Our second season starts in November. First season was great. Be careful your alternator can handle the continuous full load or limit its output. You might burn it out.

600 watts solar
35 amp alternator cut to 80% on 115 HP Westerbeke
Blue Sea 3.5 kw charger inverter
12.5 kw generator
24 volt fridge and freezer
All LED lighting
Electric autopilot

[lateral]

Any reports after 5yr+ for fireflys?

[Britishsea]

Like the original poster, I too have had a Firefly G31 fail on me after 18 months.

I purchased two G31 for a small 12 volt bank on a sail boat. Mostly cycled to 50% with the occasional deeper discharge to maybe 12v. Never below 11.7v. My use is occasional (weekends mostly) . I am not a live aboard.

Batteries worked great until one of them failed. No issues with venting. Battery looks perfect.

Unfortunatly, I did not notice for some time the failed battery and have managed to damage the capacity of the other battery ( down to 75%, after a restoration charge).

I have a warranty claim in now for the failed battery, but I have been told the company is not very responsive to claims. Purchase was through a big, authorized, reputable North American dealer. Now stuck in limbo awaiting an outcome.

Even if the warranty is ultimately honoured, I'm reluctant to put a good battery in a bank with a damaged battery - and even more reluctant to purchase another Firefly product to make a 100% new bank, given my first Firefly purchase experience.

Perhaps it was just a phase in their manufacturing that had a bad run? Mine would have been made in the Spring / Summer of 2018.

Given the price point of these batteries, this is a very disappointing out come. All my other AGM marine batteries lasted at least 7 - 8 years.

BritishSea.

[lateral]

Appreciate that, thanks.

[Pegu Club]

An update on our two group 31 firefly batteries. Soon to start the the third year of use. They are doing just fine. We charge them with two one hundred watt Renogy flexible solar panels on the Bimini, each with their own MPPT controller, and or with the 70 amp alternator on our Beta 16 diesel. They have yet to go below 73% SOC. We use a BALMAR battery monitor. The batteries have for the most part been ignored. We have been cruising the east coast and Bahamas full time since their purchase. Our major draw items are the Engle fridge, endless recharging Of the lap top, phones, IPod, hot spot, Bose speakers etc, a Zeus 2 7” chart plotter, we do use an auto pilot and a windlass, but the engine is running while those are in use. From our experience with the G31 fireflies we would recommend them. Some day we will run them down to under fifty percent SOC but the gods have been kind thus far...

Fair winds, and stay healthy,

[Britishsea]

Pegu,

your power usage and systems seem very close to mine. My biggest consumer is a Dometic compressor but it draws only 4amps and runs maybe 1/3 of the time here in the PNW. Other than refrigeration, GPS and Autohelm take some power during the day, but is mostly made up while powering into an anchorage and getting the hook down. We rarely spend more than one night at the same anchorage, but if we do, I have 200 watts of solar with a small Victron MPPT I can put out on deck on a temporary basis.

I have a Balmar 110 alternator and 614 regulator that I have derated to 75 amps. I have also set up a 'small engine mode' switch on the Balmar (further derates to about a 40 amp output ) and typically charge on that profile if the batteries are above 50-65% SOC in the morning and we anticipate some motoring time that day.

I was concerned that two G31 would not be enough power, but in fact it's perfect for how we use our boat.

Shore charging is with a Blue Sea P12 which has an California energy compliant setting which will turn off float after about 12 hours and then only re-float when the bank voltage drops below a certain threshold. This is apparently good for the FF as I understand they don't like a constant float charge.

[OceanPlanet]

Originally Posted by Britishsea

Pegu,

your power usage and systems seem very close to mine. My biggest consumer is a Dometic compressor but it draws only 4amps and runs maybe 1/3 of the time here in the PNW. Other than refrigeration, GPS and Autohelm take some power during the day, but is mostly made up while powering into an anchorage and getting the hook down. We rarely spend more than one night at the same anchorage, but if we do, I have 200 watts of solar with a small Victron MPPT I can put out on deck on a temporary basis.

I have a Balmar 110 alternator and 614 regulator that I have derated to 75 amps. I have also set up a 'small engine mode' switch on the Balmar (further derates to about a 40 amp output ) and typically charge on that profile if the batteries are above 50-65% SOC in the morning and we anticipate some motoring time that day.

I was concerned that two G31 would not be enough power, but in fact it's perfect for how we use our boat.

Shore charging is with a Blue Sea P12 which has an California energy compliant setting which will turn off float after about 12 hours and then only re-float when the bank voltage drops below a certain threshold. This is apparently good for the FF as I understand they don't like a constant float charge.

Ahoy Britishsea,

Did you get the warranty replacement handled? We haven't heard about it from this end. If the ball seems dropped, please send us an email.

What absorption voltage do you have set for the Balmar, the solar, and the shore charger? And for the float voltage? Just checking...

[Britishsea]

Bruce,

thank for your email.

Charging on the Balmar was 14.4v bulk (or what Balmar calls bulk, in reality absorb- stage 1) , 'Absorb' 14.3 and 13.4 float.

Victron MPPT (75/15) and Blue sea P12 shore charger set to 14.4 absorb and 13.4 float.

Warranty claim response pending but at this point it's only been a couple of weeks. Thxs for the kind offer of support.

[OceanPlanet]

Originally Posted by Britishsea

Bruce,

thank for your email.

Charging on the Balmar was 14.4v bulk (or what Balmar calls bulk, in reality absorb- stage 1) , 'Absorb' 14.3 and 13.4 float.

Victron MPPT (75/15) and Blue sea P12 shore charger set to 14.4 absorb and 13.4 float.

Warranty claim response pending but at this point it's only been a couple of weeks. Thxs for the kind offer of support.

Thanks, those settings look good. Note that 13.5 is also ok for float. Sometimes we set the alt. reg. to float @ 13.5 after Abs, so that in case of motoring with little or no electrical loads, the alt output will become the only source (over solar, etc.). This helps prevent the "zero rpm" syndrome of the alt. where the output is zero and thus no stator/rpm signal is sent from the alternator. This is more of an issue with Li batteries, however on installations with large solar arrays it can happen with Pb batteries as well (solar covers all the loads, no need for alt. thus zero rpm showing on engine panel).

Another note is that we've been trying some restoration tricks here on some warrantied Firefly G31's in the OPE shop. We had nothing to lose...;-) Turns out that if one has the capability for full charge/discharge/recharge cycles, then very controlled overcharging, the Firefly MCF can often be brought back to a surprising level of restored capacity. For example, one warrantied G31 tested at only 46Ah after initial charge/discharge. Subsequent full cycling brought it up a fair amount to around 70Ah. Much better, however we wanted more.

So, in collaboration with Nigel Calder and with some info from the Firefly folks, and after fully recharging (to 14.4V; until <.5A current) we did a controlled overcharge with a programmable power supply of 3A or less, limiting max voltage to <16.0V. That is, charge @ 3A however reduce the current to <3A if necessary to keep the voltage under 16.0. After a few sessions of several hours each with test discharge cycles in between (total overcharge time around 16hrs, IIRC), the battery was revived to over 98Ah of capacity.

We know that this may not be something that everyone can do, and please contact us before trying. For instance, aside from having a programmable power supply, should also watch for hot spots on the battery, gassing off, etc. We didn't have any such issues here, but do need to watch them carefully. In any case, it's interesting that the Firefly MCF likes both the full discharge/recharge (down to 10.5V) and the rather aggressive overcharge treatment.

We've done this to a couple of warrantied G31's so far, and will perhaps more aggressive overcharging, just to see at one point the capacity might crash from the abuse. Nothing to lose...

Bruce

[Britishsea]

Bruce,

thanks for sharing your finding on an 'equalization' charge for the Firefly G31.

I did try to do back-to-back restoration charges but only got to about 75ah capacity. I may try your technique to see if i can rejuvenate the second battery (& I realize that these over-charge techniques are hazardous and will take appropriate precautions).

Quick question - for the rejuvenation charge to be effective, have you found it makes a difference at what rate you charge back to full? I.e. will a 0.1C charge work as well as a 0.4C charge?

I ask as it's easier to do the restoration charge at my home garage, given all the time it takes to charge/equalize/discharge several times, and my charging sources are limited to around 12 amps max at my house. The boat has a 40 amp shore charger, which would be the other option.

[OceanPlanet]

Originally Posted by Britishsea

Bruce,

thanks for sharing your finding on an 'equalization' charge for the Firefly G31.

I did try to do back-to-back restoration charges but only got to about 75ah capacity. I may try your technique to see if i can rejuvenate the second battery (& I realize that these over-charge techniques are hazardous and will take appropriate precautions).

Quick question - for the rejuvenation charge to be effective, have you found it makes a difference at what rate you charge back to full? I.e. will a 0.1C charge work as well as a 0.4C charge?

I ask as it's easier to do the restoration charge at my home garage, given all the time it takes to charge/equalize/discharge several times, and my charging sources are limited to around 12 amps max at my house. The boat has a 40 amp shore charger, which would be the other option.

Hi Britishsea,
I'd suggest doing the full recharging/cycling at the boat (that is, from fully discharged back to 14.4/.5A), then disconnecting and taking them home for the science project. Then you won't need to do bulk charging at home.

I suppose for testing after the overcharge treatment the 12A might work. However, one of the things that we think helps with the restoration is the heating up of the battery when recharging (we hit 40C when recharging @60A, and up to 50C ok if no concentrated hot spots). The heating apparently actually helps increase the capacity.

Be sure to stay within the 3A/16.0V limits when doing the overcharge treatment.

[Britishsea]

OK, thxs Bruce. I suspected that for the rejuvenation charge FF wants a high charge rate, but the G31 manual is silent on this detail. Hopefully others will find this helpful.

BTW, for clarity - the battery that I have managed to get back to 75ah is not the warranty claim battery. It's the battery that was in parallel with the claim battery. The dead battery is close to 7ah capacity at a C.05 discharge.

[OceanPlanet]

Originally Posted by Britishsea

OK, thxs Bruce. I suspected that for the rejuvenation charge FF wants a high charge rate, but the G31 manual is silent on this detail. Hopefully others will find this helpful.

BTW, for clarity - the battery that I have managed to get back to 75ah is not the warranty claim battery. It's the battery that was in parallel with the claim battery. The dead battery is close to 7ah capacity at a C.05 discharge.

Roger that. Attached is the current manual which has reference to the preferable occasional fast charging.

You might try the overcharge treatment on both batteries...you certainly have nothing to lose on the 7Ah one! However sounds like that one may have a critical failure.