Interesting behavior - Firefly batteries, Balmar Smartgauge, small solar panel

[phantomracer]

At least i find it interesting..

have 2 firefly batteries in parallel, with a small portable 30w solar panel using a Genasun GV-4 controller.

When I put the boat on the mooring, with say, 80% of charge according to the Balmar Smartgauge, I come back a few days later, the solar controller has maxed out (solid light) indicating the battery is 'full'.. but the Smartgauge reads something like 94%. Unsure if the charge controller is still working and I haven't waited long enough to get to 100%, or its done charging..

Either way, Its kinda cool to see the small panel and the GV4 charge controller seems to be up to the task to topping the battery off on the mooring. I am guessing the controller has a different methodology on deciding when the battery is at 100% compared to the smartgauge. Then again the SG is probably still learning.

Then again, the firefly batteries don't care about being topped off like other batteries. I do like having as many amps available due to running the refrigerator.

[a64pilot]

Almost all charge sources will prematurely drop into float.
May not much matter with your firefly, but it does with other batteries.
What you have Is say is normal behavior for a charge source.

[phantomracer]

Thats what I figured.. Not overly worried.. which is why I got the firefly

I am guessing doesnt matter if I had 3000w of solar or 30, if it stops when it gets full, it will be the same..

Unsure if the genasun will be charging in float mode to bring it to 100% Maybe if I waited a few more days it might get there.. ? unsure..

I just found it interesting and figured I would share... Charging on the hard with a power supply, it would get to 100%, and when motoring for awhile, it would get to 100%. so the smart gauge is learning..

But like I said, i did find it interesting.

if this is typical behavior, if the charging does stop before the batteries are topped off, is it conceivable that they could start having issues with them being walked down in capacity over time?

But so far thrilled with the Firefly batteries.. not having to baby them.. performance is great.. quick to charge! time will tell how they perform.. but initial impression is excellent.

[rgleason]

phantomracer, I was considering a configuration very similar to yours in this spreadsheet
Small Boat Electrical System for Sail

I would be interested in your thoughts/experience. How long ago did you get them? Were they hard to obtain? Wait period? Do you like them so far?

I was considering a one day charge from SOC 80% to SOC 100% with 150 watts to recharge (2) Firefly Oasis 220ah in one day with 5hrs of sunlight. That is about 12.5 amps of solar which would exceed my Genasun controller, but would the batteries accept that? Maybe it is too much solar to mount for the batteries and the charge to 100% probably has to occur over several days?

Is it too much for flooded too?

[rgleason]

2 firefly batteries in parallel, with a small portable 30w solar panel using a Genasun GV-4 controller.

(I found this open after a glitch and after I had rewritten it, so I am posting it.)

Very interesting. You have a configuration similar to one I was considering

Small Boat Electrical for Sail when did you get the batteries and how do you like them so far? They may help us with "psoc" and sailing off a mooring, however another alternative would be to have a good and adequate solar installation.

I did a little study in the spreadsheet trying to equalize Trojan T105 and Firefly Oasis and it looked to me like the Oasis started being less expensive provided they work as stated and last long enough. What do you think?

I'd be interested in your thoughts about that spreadsheet too.

PS: I was going to say, that I've noticed my Link10 is showing differences from my Balmar ARS-5 regulator for example and I was thinking it might be where the sensors are located. I have cleaned all connections this spring and made sure all bus screws and contacts are tight. Little things seem to make a difference.


I was thinking I would need
SOC 80% ---> SOC 100% = 20% x 220 = 44ah of solar.
If I multiply that times 12v x 44 ah = 528 watts/day
but I have 5 hours of daylight so I need 106 watts/hr.
but there are inefficiencies so I need more 106/.70 = 151 watt panels needed.

Will the batteries accept at that rate between SOC 80% and 100%?

[phantomracer]

Not an expert by any means... proved by the expensive batteries i have killed over the years!

talk with https://www.bruceschwab.com/ and mainesail and others about specifics..

I like the FF as I dont have to do any math.. can leave them in any state of charge, confident they will shake off any PSOC.

so far in 3 seasons(?) they still feel new. charge quickly and last for what seems like forever, even with the fridge running until the fuel cell kicks on. Still on the fuel from last year actually. With the old flooded batteries, it would come on if I looked at it the wrong way!!

Figured I would start with 2 FF batteries.. could add more if i needed. 2 seems to be more than enough for my needs at the moment.

i had no wait to get mine, they were shipped from Maine to me in Boston, for about $50.. so cant complain about that. But have heard there are times where there is a wait list.

I just got the panel because it was cheap and the genasun helped squeeze another amp or so out of the panels to help it charge better. seems to be up to the task. Its always in float mode when i go back to the boat after a few days. But I find the fuel cell excellent for extended stays on the boat instead of having a couple acres of panels on the boat.

[john61ct]

No controller by itself has a way to judge SoC accurately.

The owner needs to use an ammeter to judge when 100% Full is reached, as per endAmps.

Any decent controller will allow Absorb Hold time to be extended until the owner sees 100% is being reached most cycles.

Even for Firefly that will ensure good longevity, and is needed for their capacity recovery protocol.

If the SG does not reflect the 100% point properly, then use the reset switch a bit below the endAmps point.

It can take a dozen cycles or so after that for SG to learn your bank's characteristics, so don't reset often, unless you find it necessary after a few hands-off attempts.

[phantomracer]

Originally Posted by john61ct

No controller by itself has a way to judge SoC accurately.

The owner needs to use an ammeter to judge when 100% Full is reached, as per endAmps.

Any decent controller will allow Absorb Hold time to be extended until the owner sees 100% is being reached most cycles.

Even for Firefly that will ensure good longevity, and is needed for their capacity recovery protocol.

If the SG does not reflect the 100% point properly, then use the reset switch a bit below the endAmps point.

It can take a dozen cycles or so after that for SG to learn your bank's characteristics, so don't reset often, unless you find it necessary after a few hands-off attempts.

Oh I agree. it was just some initial observations. Thought it was kind of interesting, as well as the fact this cheap little panel was able to do a decent job of topping off the battery in such a short time using an inexpensive MPPT controller.

The smartgauge has gone to 100% a few times with the battery charger and the alternator, figured I would just use the boat and not fuss over it too much. I figure over time it will find its level. But surely is more useful than just looking at a volt and amp meter!

[billknny]

I have Firefly batteries in a very different system than you (Eight batteries in parallel/series to make a 470Amp-hr 24 volt bank), but I have a similar issue...

I have found my Smartgauge to have a very hard time with tracking low charge rates (like from solar). The have no trouble keeping track when my genset pumps 150 amps into them, but 25 Amps from the solar panels means the Smartgauge just hovers down at the place charging started. It does seem to pick up again as the state of charge come down again.

I love my Fireflies, and I loved my Smartgauge when I had standard AGM's. But they do not seem to play well together.

[john61ct]

Actually many Firefly + SG users say it is accurate once it learns, may need to use the 100% reset occasionally just before endAmps is reached, but that needs doing every time for accuracy with the AH-counting BMs.

More likely, with constant loads and a small wattage charge, the bank is simply not getting to endAmps 100% SoC.

Remember in best case conditions that takes 5-8 hours, and even in decent insolation conditions, the actual charging day may not be that long.

Use dino juice to get to 90% full before that starts, isolate from loads, and you'll likely get a very different result.

[CarlF]

I wonder if the Firefly's are "different" enough that the Smart gauge needs a special profile? The Firely manual specifies a Peukert constant of 1.07 for 10 and 20 hour rates. My old Lifelines specified 1.12. Although, frankly, I've never seen these Peukert rates work as predicted. Has anyone asked Balmar if the Smart Gauge is accurate with Fireflys?

In any case, Firefly is very clear in the manual: "You DO NOT need to fully charge the Oasis each cycle in order to maintain the capacity and only need to perform a complete charge cycle when you want to maximize the capacity for the following discharge cycle." OVer a long perioud of PSOC there is supposedly minor capacity loss that can be recovered with a restoration charge.

I have just installed 8 Firefly's to replace very carefully maintained Lifelines that showed substantial capacity loss after just three years. It's too early to judge the Firefly's but I am very hopeful.

The Fireflys have been essentially on order since last September. One story is that Firefly moved some production to India and had troubles. I believe the more likely reason is that they received some large orders (perhaps government) that pushed retail buyers to the back - but that is just conjecture. In any case, the supply bottleneck may be ending.

[dfelsent]

I’ve seen the smartgauge consistently show charge in the 80s when I know that my vrla lead acids are fully charged when using a wind generator. I think this is a known behavior that long term slow charging can cause lower readings than actual charge.

[rgleason]

And Mainsail says not to trust clamping meter or link10 at these low currents
"The owner needs to use an ammeter to judge when 100% Full is reached, as per endAmps."
so what where does that leave us?

But your point is, I think, that no matter what batteries you use, you must know what is going on, such as when 100% SOC is reached.


Even Firefly "complete charge cycle when you want to maximize the capacity"

I suppose you should stop at 100%SOC?
Of course no equalize is wanted.

[phantomracer]

Originally Posted by CarlF

I wonder if the Firefly's are "different" enough that the Smart gauge needs a special profile? The Firely manual specifies a Peukert constant of 1.07 for 10 and 20 hour rates. My old Lifelines specified 1.12. Although, frankly, I've never seen these Peukert rates work as predicted. Has anyone asked Balmar if the Smart Gauge is accurate with Fireflys?

In any case, Firefly is very clear in the manual: "You DO NOT need to fully charge the Oasis each cycle in order to maintain the capacity and only need to perform a complete charge cycle when you want to maximize the capacity for the following discharge cycle." OVer a long perioud of PSOC there is supposedly minor capacity loss that can be recovered with a restoration charge.

I have just installed 8 Firefly's to replace very carefully maintained Lifelines that showed substantial capacity loss after just three years. It's too early to judge the Firefly's but I am very hopeful.

The Fireflys have been essentially on order since last September. One story is that Firefly moved some production to India and had troubles. I believe the more likely reason is that they received some large orders (perhaps government) that pushed retail buyers to the back - but that is just conjecture. In any case, the supply bottleneck may be ending.

Yes when I talked with Balmar.. they said it was close enough to AGM to be close enough.. but not perfect.. But even if it is within 10% of accurate I will be happy. I think it is a lot more accurate than that.

Being somewhat on the bleeding edge, figured I would share what I have witnessed, although not a true scientific study.. just real world experience.

Yes I am not concerned at all about fully recharging them. even when hauling at the end of the season, i didnt even check or charge the batteries til the spring.

[john61ct]

Originally Posted by CarlF

I wonder if the Firefly's are "different" enough that the Smart gauge needs a special profile? The Firely manual specifies a Peukert constant of 1.07 for 10 and 20 hour rates. My old Lifelines specified 1.12. Although, frankly, I've never seen these Peukert rates work as predicted. Has anyone asked Balmar if the Smart Gauge is accurate with Fireflys?

No SoC meter is that accurate, just that SG ballparks better than the others, 4-8% is as good as it gets without huge pricey lab gear.

And Peukert constant actually changes with current and SoC anyway, not a fixed number.

> The Fireflys have been essentially on order since last September. One story is that Firefly moved some production to India and had troubles.

The US company was bought by Indians. All production has moved, only the G31 was ever US based.

And demand will increase with availability.

Mine took 5 months.

Work through Bruce @OceanPlanet, master distributor for NA markets.