Firefly vs Lithium ?

[Suijin]

Originally Posted by Training Wheels

Firefly recommends fully charging their batteries only once every 30 days.

Which is awesome.

I think the big question with Firefly's is what the endgame looks like, and no one has been there yet to tell the story. Mainsail's testing of them would indicate they are basically magic; he's abused them far worse than charging them fully every 30 days and they pop back to 100% without a hitch. Mind boggling. Firefly estimates that they will last 10 years, but non one really knows at this point, at least from what I've gathered.

It seems like the main argument for Lithium at the present time is space/weight combined with charging profile. Based on a few calculations, from a lifetime cost perspective they come out roughly even with quality AGMs that are treated well.

From what you have outlined, I think the Fireflys are probably a sound choice. They meet your usage profile, they are effectively cost competitive in your market, and they will fit.

I will say I'm with others about keeping your genset, at least for the time being, unless you have a compelling reason to yank it, and weight does not strike me as one. Cruise for a year or two and if you can do without, then make the decision to deinstall it. Remember, with a portable Honda you'll need to carry gas and deal with noise, set up, etc. Would suck to decide after a year that you wish you had your diesel back.

[fxykty]

Still debating the FF vs LFP, as I’ve now found another supplier in NZ that sells Sinipoly 4 cell 12V batteries for only a few hundred dollars over the cost of the FFs, though about another thousand for BMS and the controllers needed for a LFP bank. Sigh, more investigation. I just wish there weren’t so many contradictory expert opinions around LFP. Who to trust when you’re not an electrical engineer?

Regarding the generator, lots of people cruise without them. If each of my two engines can generate the same amount as my generator, why keep the third engine? Removing it and selling it will pay for upgrading my engines charging capacity and about half of the new battery bank. I admit that part is short term thinking. We are planning to cruise Patagonia one day, after wintering over in Alaska, so maybe we will rue our decision, but I still don’t get the reason to run a generator just to rest a propulsion engine. Especially if you only have to do this once or twice a fortnight.

I appreciate all of your comments and experiences. Thanks.

[Factor]

Absolutely ditch the genset on an O55, more solar, better alternators and more efficient charge control systems. Lighter weight - less complexity etc etc.

A couple of years ago I saw an O55 in Puerto Natales in Patagonia on its way to Antarctica. I think it does skippered charters in the Carribean now.

Buggered if I know how it survived 60 degree latitude sailing though :-).

[Factor]

Originally Posted by Suijin

Remember, with a portable Honda you'll need to carry gas and deal with noise, set up, etc. Would suck to decide after a year that you wish you had your diesel back.

Portable is quieter than most diesel gensets I have experienced. As for carrying gas (I resume you mean Petrol, I always get confused when Americans talk about Gas - I think of well ---- gas, as is not liquid not solid, anyway I digress) Most people cruising already carry enough to blow the boat up for their dinghy motor.

[fxykty]

Originally Posted by Factor

Absolutely ditch the genset on an O55, more solar, better alternators and more efficient charge control systems. Lighter weight - less complexity etc etc.

A couple of years ago I saw an O55 in Puerto Natales in Patagonia on its way to Antarctica. I think it does skippered charters in the Carribean now.

Buggered if I know how it survived 60 degree latitude sailing though :-).

That was Angelique II of www.TheLifetimeCruise.com, a 1993 O55 Standard that was insulated waterline up and had a big refit a few years ago. Fabulous photos and videos and very interesting owners, but I guess their charter/academy business idea didn’t pan out.

She is currently for sale on Yachtworld. If you’re looking for a blue water performance catamaran well equiped for cruising anywhere with 4 cabins 4 heads she’s one to look at.

[zboss]

Originally Posted by Training Wheels

Firefly recommends fully charging their batteries only once every 30 days.

Where did you see this? This was not in any literature or any conversations we have had with firefly dealers. They recommend the restore charge once a year.

[john61ct]

Realize that ultra-honest non-FF folk like Maine Sail and Bruce are not in charge of FF marketing and sales verbiage output coming from the Indian parent operation.

Yes these are relatively "magical" but did not repeal the laws of physics, au fond they ae lead AGM batts.

I'm not saying the FF restore charge cycle is necessary to do frequently, if you're not PSOCing.

But it is definitely the case that they will last longer to the extent - if you have the chance - you can get to 100% Full as per endAmps.

Same with sticking to 50% DoD.

Sure they will "cope with" what would be quick murder with any other lead bank.

But proper coddling will make them last longer.

[Training Wheels]

Originally Posted by zboss

Where did you see this? This was not in any literature or any conversations we have had with firefly dealers. They recommend the restore charge once a year.

From Firefly in their charging recommendations leaflet. I just reread it and it actually says 20 to 30 days, and for best life, cycle them from 10% to 90% SOC.

[witzgall]

I am a big fan of "Opportunistic charging" IE charging when motoring. The dirty little secret of us sailboat cruisers is that we motor a lot.

Upgrading to external regulation should give you some big benefits. Among the normal described is you can fine tune the charging to ensure you are fully charging your batteries, ie not cutting off the absorption stage too early. This is the kind of thing that will short-life batteries. Just make sure you put a temp sensor on your alternator to the regulator, as you may be asking those existing alternators to work pretty hard when the batteries are more than 20% discharged.

Full disclaimer, I work for Balmar. If you happen to have Valeo alternators on Yanmar engines, we have a kit that makes it really easy to convert to external, P type regulation. If not, any good alternator/starter shop can do the conversion for you.

Finally, I would consider keeping the genset in place until after you done the alternator upgrades, and seeing if you can do without. Then you will know for sure.

Chris

Originally Posted by fxykty

I don’t understand the ‘keep the generator’ advice given what I’ve already written. The major con is that it is a third engine to maintain and it has no purpose other than to charge batteries. Upgrading the engines’ charging will substitute for the generator’s charging capacity, and most of the time the engine charging will be a by-product of using them for propulsion. Doubling the solar to start will take care of the rest. If we find that we desperately need a generator every fortnight or month then we’ll buy a portable. A tenth of the cost and easier maintenance.

Regarding life, the premium AGMs we’ve got now have demonstrably deteriorated in 4 years, with perhaps another two years of life. And FLA golf cart batteries and replacement AGMs are not tolerant of our usage profile.

FFs claim a decade of use. That’s still to be determined as I don’t think anyone has had them that long, but they certainly do have 3-4x the cycles at 50% DOD. Refer to www.bruceschwab.com for the specifications.

What’s the hassle with importing batteries? You buy stuff overseas all the time don’t you?

Even if available in NZ, battery prices here are high relative to even Australia, which is also a high cost region. Direct importing with the help of a broker is not that hard.

[Pete O Static]

I changed out my old AGM's for the Firefly. The real point that nobody has brought up yet, whether you go with Firefly or Lithium, is that rather than just changing the battery, you really need to change the system as a whole to reap the full benefits.

I didn't go with Lithium simply because of the initial cost and that the technology is changing too rapidly for me to justify that cost. The firefly was about the same price as a similarly sized Lifeline AGM.

However, to take full advantage of the Firefly, I also changed my charging system. The advantage of the Firefly is that it has a very high charge acceptance rate and does not need to be charged back up to 100% each cycle. I swapped out my Alternator to the highest output I could put on my engine. ( also matched to the banks capacity and C rating. ) This meant installing a serpentine belt kit to drive it, along with an external regulator with temp sensor. Now, whenever my engine is running, the Firefly's are very rapidly charged back up to 80% and more than happy if I don't push them all the way up to 100%. For the majority of the time, my batteries are cycling between 20% and 80% capacity. I can replace that 60% very quickly during a rapid bulk charge from the engine driven alternator. The solar panels will take care of the remaining 20% over time.

With a very modest solar array of 290 watts, I find the only reason I start my engine is to either move the boat or to re heat the hot water tank. The firefly gives me more useable capacity so I was able to achieve the same with a smaller bank.

I avoid marinas at all costs and do not plug in very often at all. However, I also leave the house at home when I am on the boat. That includes air conditioning, internet, computers and most anything else I don't really need, except ice cold beer. That is an absolute No Go.

[exMaggieDrum]

FYI - a friend of mine just tried to buy some Group 31 FF's from a big retailer here in Washington state. The retailer says they are one of Firefly's preferred sellers and usually get the batteries in as fast as any other company.

However, they have been sold out for several weeks and the next shipment is expected on June 25th, or about 5-6 weeks from now. And they said that the shipments are usually sold out with backorders before they arrive.

They say that FF cannot keep up with demand and are not sure when that will change. My friend says he will not be trying to get them at the moment.

[john61ct]

Yes, I had to wait over six months for my bank, arrived four months ago.

Best is to contact Bruce and ask his advice, some dealers may have stock on hand.

Unless demand continues to rise I'd expect the bottleneck to ease within a year.

[Davidhoy]

Originally Posted by exMaggieDrum

I've installed lithium-iron-phosphate (LFP) batteries recently and am happy with that decision.

Which BMS did you go with for your LFP bank? I'm planning one right now, and have yet to pick the BMS so any input would be appreciated.

Regards,
David