Topics

Lithium Batteries under Consideration


michael winand
 

Hi Scott,  in the early days of producing them there were a few issues, these could have been from those. 
I am running a set of 8 g31 in the super maramu. Just coming up to 2 years. Would say around 300 cycles down to 60 to 70 percent. We use around 150amps overnight  
1 freezer. 2 fridge's. 
Recent additions of  1kw of solar see them topped off around 3pm.
Main battery charger is a 120amp quattro.
Alternator is a 150 amp electrodyne  going through a balmar 624.
I have the victron battery balancers. 

They charge fast  i have seen the Alternator put 165amps into the bank. 
You will need to program the charger and Alternator regulator to suit. 
Very low discharge,  left disconnected for 4 months, put the small 15 amp charger on each battery to top off and 15min was all required. 

Like any battery system. It needs to be set-up, monitored, understood. 
Any type can be damaged. 
Lithium  needs low voltage disconnect. 
So far they are going well, probably know if they are living up to their claims in another year of full time cruising. 
Food for thought 
Michael Nebo sm251 



On Tue, 24 Nov 2020 at 2:58 pm, Scott SV Tengah
<Scott.nguyen@...> wrote:
Michael,

I am not sure if they are worse. Given that Jamie was getting below 24 volts overnight after only a year, that sounds pretty bad though. Even our old gel batteries weren't that bad.

My concern with Firefly was that the sales pitch was that you could run them down to low SOC without damaging the battery, but if the voltage sags so much, the batteries may not get damaged, but your boat will not like the low voltage. Therefore the ability to take it to low SOC is only academic.



On Mon, Nov 23, 2020 at 10:48 AM michael winand via groups.io <mfw642000=yahoo.com.au@groups.io> wrote:
Hi Scott,  would you suggest that the firefly batteries are worse than other lead batteries regarding their voltage drop curve?
I would think that the state of change would have been important to know. 
Thanks  Michael  Nebo sm251 



On Tue, 24 Nov 2020 at 2:23 am, Scott from SV Tengah
Arno,

I think it would be best if Jamie could chime in. He replaced his Fireflies precisely because he experienced severe voltage drop under load, one of the "hidden" downsides of carbon foam. As always, there could have been other confounding factors. That said, I would be careful trusting specs. The Victron Battery Protect should have worked fine on my system but instead melted within a day. 

Regarding gen usage during BT, I spent about a year diagnosing and fixing my BT, so learned a bit more than I ever wanted to know. My understanding is an Amel54 owner experienced a solenoid that melted closed because ohm's law tells us that when voltage drops, amps have to increase to compensate. That owner spun like a top in the marina. That's why Amel suggested that I install an emergency stop switch.  My understanding is that repeated use (think 30 knots on the beam in a tricky marina) will result in cumulative voltage drops so the genset/charger is supposed to help the batteries recover a bit between uses, not replace the batteries.

I considered carbon foam as a cheaper, easier upgrade than lifepo4, but decided against them for the voltage drop issues. 
If you look at the firely SOC vs. voltage curves, you will see that the main benefit of being able to deeply discharge and also not fully recharge is negated by the fact that voltage drops to unacceptable levels at low SOC.

Here's another guy who took the baby step and then ended up going all the way. That said, I understand your use case is primarily marina life, so in your case, I would not get lithium either. Just wanted to make the info available to people who live full time off the grid who think Fireflies are lithium like:
https://www.cruisersforum.com/forums/f14/firefly-oasis-voltage-sag-225444.html#post3002627

Perhaps you will have better success with respect to voltage drops than others who have tried. 



--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Scott SV Tengah
 

Michael,

I am not sure if they are worse. Given that Jamie was getting below 24 volts overnight after only a year, that sounds pretty bad though. Even our old gel batteries weren't that bad.

My concern with Firefly was that the sales pitch was that you could run them down to low SOC without damaging the battery, but if the voltage sags so much, the batteries may not get damaged, but your boat will not like the low voltage. Therefore the ability to take it to low SOC is only academic.



On Mon, Nov 23, 2020 at 10:48 AM michael winand via groups.io <mfw642000=yahoo.com.au@groups.io> wrote:
Hi Scott,  would you suggest that the firefly batteries are worse than other lead batteries regarding their voltage drop curve?
I would think that the state of change would have been important to know. 
Thanks  Michael  Nebo sm251 



On Tue, 24 Nov 2020 at 2:23 am, Scott from SV Tengah
Arno,

I think it would be best if Jamie could chime in. He replaced his Fireflies precisely because he experienced severe voltage drop under load, one of the "hidden" downsides of carbon foam. As always, there could have been other confounding factors. That said, I would be careful trusting specs. The Victron Battery Protect should have worked fine on my system but instead melted within a day. 

Regarding gen usage during BT, I spent about a year diagnosing and fixing my BT, so learned a bit more than I ever wanted to know. My understanding is an Amel54 owner experienced a solenoid that melted closed because ohm's law tells us that when voltage drops, amps have to increase to compensate. That owner spun like a top in the marina. That's why Amel suggested that I install an emergency stop switch.  My understanding is that repeated use (think 30 knots on the beam in a tricky marina) will result in cumulative voltage drops so the genset/charger is supposed to help the batteries recover a bit between uses, not replace the batteries.

I considered carbon foam as a cheaper, easier upgrade than lifepo4, but decided against them for the voltage drop issues. 
If you look at the firely SOC vs. voltage curves, you will see that the main benefit of being able to deeply discharge and also not fully recharge is negated by the fact that voltage drops to unacceptable levels at low SOC.

Here's another guy who took the baby step and then ended up going all the way. That said, I understand your use case is primarily marina life, so in your case, I would not get lithium either. Just wanted to make the info available to people who live full time off the grid who think Fireflies are lithium like:
https://www.cruisersforum.com/forums/f14/firefly-oasis-voltage-sag-225444.html#post3002627

Perhaps you will have better success with respect to voltage drops than others who have tried. 



--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Dean Gillies
 

Bill Kinney, maybe you could also 'chime in' regarding Firefly batteries. Are you still happy with them after 2-3 years?
Dean
SV Stella
A54-154


Jamie Wendell
 

Dean, I too have that issue, but the solution is to keep the fuel tank full. Maybe some lead bars behind the lithiums will do the trick?
I hope I did not cause anyone to second guess their own battery solutions, as everyone will have a different need, but I had to report my results as they are.
Jamie
Phantom, A54 #44


Dean Gillies
 

Well that bursts the bubble of having batteries that are more capable than AGM at lower SOC for half the price of LFP AND don't cause the A54 to list more to port.
I can't believe my thought pattern at the moment, but if I could buy Lithium batteries that were as heavy as AGM's then my change to Lithium would be a fait-accompli.

I just don't like the thought of the boat listing even more to port!

Dean
SV Stella A54-154


Jamie Wendell
 

Well I guess I should chime in here, so to speak. I installed Fireflys in my A54 a few years ago. They lasted about 3 years before the voltage drop started to cause problems for me. They were promoted as being "almost" as good as Lithiums for about half the price, so I thought why not.
I cannot say why they failed, but as we were yanking them out of the boat, we load tested all of them just to see how they had held up, thinking maybe 1 or 2 had simply died. Almost all of them showed significant degradation. I was able to salvage a couple of them to serve as starter batteries, but I was not a happy camper. I do have a very heavy electrical load. Perhaps the 12-volt in series configuration is not compatible unless you deliberately balance them out periodically. With 24-volt Lithiums, that is no longer a concern.

Despite the expense (2 times the Firefly technology), I am convinced that LiFePO4 is the way to go if you are looking for long-term serviceability. They hold their voltage levels even with extended bow thruster use, and I never get low-voltage alarms on my Maretron N2K bus any more. I used to get them all the time after the first year and had to wake up in the mornings to start the generator to quell the alarm. I had the alarm set to go off if the voltage dropped below 24 volts.

Sorry to put a bummer into the carbon-foam technology, as some may have had a good experience given the "better mousetrap approach," but they still are based on lead construction. I expect in the future LiFePO4 or some derivative will become the norm for our Amels.

Jamie
Phantom, A54 #44


michael winand
 

Hi Scott,  would you suggest that the firefly batteries are worse than other lead batteries regarding their voltage drop curve?
I would think that the state of change would have been important to know. 
Thanks  Michael  Nebo sm251 



On Tue, 24 Nov 2020 at 2:23 am, Scott from SV Tengah
<Scott.nguyen@...> wrote:
Arno,

I think it would be best if Jamie could chime in. He replaced his Fireflies precisely because he experienced severe voltage drop under load, one of the "hidden" downsides of carbon foam. As always, there could have been other confounding factors. That said, I would be careful trusting specs. The Victron Battery Protect should have worked fine on my system but instead melted within a day. 

Regarding gen usage during BT, I spent about a year diagnosing and fixing my BT, so learned a bit more than I ever wanted to know. My understanding is an Amel54 owner experienced a solenoid that melted closed because ohm's law tells us that when voltage drops, amps have to increase to compensate. That owner spun like a top in the marina. That's why Amel suggested that I install an emergency stop switch.  My understanding is that repeated use (think 30 knots on the beam in a tricky marina) will result in cumulative voltage drops so the genset/charger is supposed to help the batteries recover a bit between uses, not replace the batteries.

I considered carbon foam as a cheaper, easier upgrade than lifepo4, but decided against them for the voltage drop issues. 
If you look at the firely SOC vs. voltage curves, you will see that the main benefit of being able to deeply discharge and also not fully recharge is negated by the fact that voltage drops to unacceptable levels at low SOC.

Here's another guy who took the baby step and then ended up going all the way. That said, I understand your use case is primarily marina life, so in your case, I would not get lithium either. Just wanted to make the info available to people who live full time off the grid who think Fireflies are lithium like:
https://www.cruisersforum.com/forums/f14/firefly-oasis-voltage-sag-225444.html#post3002627

Perhaps you will have better success with respect to voltage drops than others who have tried. 



--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Scott SV Tengah
 

Arno,

I think it would be best if Jamie could chime in. He replaced his Fireflies precisely because he experienced severe voltage drop under load, one of the "hidden" downsides of carbon foam. As always, there could have been other confounding factors. That said, I would be careful trusting specs. The Victron Battery Protect should have worked fine on my system but instead melted within a day. 

Regarding gen usage during BT, I spent about a year diagnosing and fixing my BT, so learned a bit more than I ever wanted to know. My understanding is an Amel54 owner experienced a solenoid that melted closed because ohm's law tells us that when voltage drops, amps have to increase to compensate. That owner spun like a top in the marina. That's why Amel suggested that I install an emergency stop switch.  My understanding is that repeated use (think 30 knots on the beam in a tricky marina) will result in cumulative voltage drops so the genset/charger is supposed to help the batteries recover a bit between uses, not replace the batteries.

I considered carbon foam as a cheaper, easier upgrade than lifepo4, but decided against them for the voltage drop issues. 
If you look at the firely SOC vs. voltage curves, you will see that the main benefit of being able to deeply discharge and also not fully recharge is negated by the fact that voltage drops to unacceptable levels at low SOC.

Here's another guy who took the baby step and then ended up going all the way. That said, I understand your use case is primarily marina life, so in your case, I would not get lithium either. Just wanted to make the info available to people who live full time off the grid who think Fireflies are lithium like:
https://www.cruisersforum.com/forums/f14/firefly-oasis-voltage-sag-225444.html#post3002627

Perhaps you will have better success with respect to voltage drops than others who have tried. 



--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Arno Luijten
 

Hi Scott,

According to the specs the CCA for the Firefly is 720 Amp. So the BT should be fine having 5*720=3600 startup amps available.
I don’t buy this generator story as your 100 amp battery charger cannot respond quick enough for the solenoid to make a difference. And besides it can only supply 100 amp where the startup current for the BT is probably closer to 1000 amp.
When running the BT takes about 450 Amp,, about 80 amp per battery. If your batteries cannot supply that, you need to replace them anyway...

Cheers,

Arno
SV Luna
A54-121


Scott SV Tengah
 

To continue the thread drift 😇, perhaps Jamie on phantom can chime in about his experience with carbon foam. 

He had fireflies before I think and experienced severe voltage drops under load to the point where his fridges started failing. 

I'd be a bit concerned about using the bow thruster with a battery that experienced severe voltage drop under load. I guess you could just run the generator when using the bt as amel recommended to avoid melting your solenoids.


--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Arno Luijten
 

Hi Randall,

I'm not exactly sure but I think the current price-point is around USD 400 each and you would need 10 in total to get similar capacity as for 12 AGMs. The weight of these batteries is slightly higher so putting in 12 may give problems with the boat listing to starboard. As the usable capacity per battery is higher then for AGM, I will order 10 pieces to replace my failing AGM set. I'm also planning to replace the starter battery with one of these batteries as a sort of spare battery. In case one fails I have a spare as starter batteries are much more easy to obtain. So in total I'm ordering 11 pieces.

Regards,

Arno Luijten


Randall Walker
 

Hello Arno,
I am in the process of replacing mine, What is the price range you have?

Cheers,
Randall

Virus-free. www.avg.com


On Fri, Nov 20, 2020 at 6:03 PM Arno Luijten <arno.luijten@...> wrote:
For those in the vicinity and that also think Lithium is still too much complication for their needs, we are currently doing a group-purchase of Firefly Carbon Foam batteries on St. Maarten in the Caribbean.

If interested, let me know as the more we buy the better the price will be.

Arno Luijten
SV Luna,
A54-121


Arno Luijten
 

For those in the vicinity and that also think Lithium is still too much complication for their needs, we are currently doing a group-purchase of Firefly Carbon Foam batteries on St. Maarten in the Caribbean.

If interested, let me know as the more we buy the better the price will be.

Arno Luijten
SV Luna,
A54-121


Grant Starling
 

Dean,

Yes, both are 12v, I have a Santorin which runs a 12v system, I guess if you are running a 24v house bank that would complicate it some, but there is probably a solution out there.

Scott,

It is a lot of capacity but I converted the entire boat to electric, no gas, so we do have a larger capacity need as we are running a convection oven/microwave combo and 2 plate induction hobb, plus toaster, kettle etc etc.  I have a victory multiplus 3000w inverter charger running the show.  I will eventually have 800w solar on arch and hardtop and a decent wind generator which should mean little if any generator requirement.

Of course until I am actually out on anchor for an extended period I won’t know for sure.  But can add components as required to properly balance the system.  I took the decision to err on the side of caution capacity wise.

best
Grant


Alan Leslie
 

Thanks Dean,
I believe that battery balancers are essential.
We have 6v 210Ah batteries in three parallel strings of 4 in series.
Each string has its own balancer for 4 batteries which I bought on Alibaba for minimal cost.
The system works well.
Cheers
Alan
Elyse SM437


Scott SV Tengah
 

Grant, that's a LOT of capacity! Since you're talking about prop shaft alternators, do you have an older Amel that runs on 12v or are you talking 900amps at 24v? We have 450ah/24v and go through roughly 200-250ah a day while on anchor. In general, solar provides that and a bit more - that said I'm not in the UK or Scandinavia. :)  My math was always that if I add more capacity and didn't have enough renewables, it would just lengthen the period between when I had to run the genset. Are you "balanced" on renewables vs. capacity? 

FWIW - the Victron tech that I spent so much time talking to advised that if I was going to add more capacity, do it within the first six months as the batteries do age (despite marketing materials) and develop higher resistance and the new ones will absorb more charge, causing potential imbalance issues. This is one engineer's instruction so take it with a grain of salt, but I find it valuable because he was basically telling me NOT to purchase more of his company's products because I waited too long. So he hates his sales colleagues and/or he was telling me the truth. 


--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Dean Gillies
 

Scott,
I would definitely agree that changing from Lithium to Lead is highly unlikely, for anyone.  I started this comparative investigation because I'm impressed by the Lithium system which came with my new "Covid" caravan. I'd be happy with similar characteristics in my Amel.

Grant,
Interesting concept. Are both your engine and start batteries are operating at the same voltage? 

cheers
Dean
SY Stella
A54-154

 


Grant Starling
 

Dean (Scott),

I did a full upgrade to lithium about a year ago and am now adding to my battery capacity which is currently 400AH with another 500AH in preparation for world cruising next year.  

Lots of good advice given in the previous posts, and I would support much of what Scott has said about the challenge of designing a ‘system’ with lithium.  Any idea of a ‘drop-in’ replacement lithium battery should be treated with caution for the reasons outlined previously.

if I can add anything to the debate it would be the use of a DC battery to battery charger (may have missed this?).  I use a Sterling B2B 60amp charger between both my 90amp engine alternator and my 90amp prop shaft alternator and my lithium bank.  This allows all my alternator charging into my lithium bank to be done via a programmed lithium profile provided on the B2B60. 

As the alternators are both linked first to my engine starter battery (Optima red top), then through the B2B to my lithium bank, they cannot (easily) overcharge my lithium bank, preventing battery BMS from disconnecting due to high current.  This system also prevents the alternators from being destroyed from a voltage spike due to BMS disconnect.  As a fail safe I can also turn off the B2B manually to stop it sending charge to my lithium bank if I feel the need I.e. I don’t like floating my lithium batteries for long so if I am on motor for an extended period I simply switch the B2B off using the remote panel at my nav station.

This setup has worked well for me so far, so check it out if you are interested.

best
Grant

SV Allonzee


Scott SV Tengah
 

Dean,

At least with my batteries, they are passively balanced. Most are. That means they don't balance between cells (even if I had a 12v system because recall that a 12v battery is 4 lifepo4 cells in series) unless you get them to 95% SOC or more. Only then do the "voltage knees" start showing up - before that, there is very little difference in voltage. Even when I had imbalanced batteries, the cells were perfectly matched up to 90%. At 95%, that's when the voltage spike became apparent and the balancing starts kicking in. I can't see how you would notice imbalance otherwise due to the voltage vs SOC curve of lithium. 

As you apply current, which will be reduced as SOC approaches 100%, that's when balancing occurs. This is all per my lengthy conversations with the Victron techs. That's how "automatic recovery" happens. Now in my 24v system with pairs of 12v in series, if you start with an imbalance between the two 12v batteries in series, the imbalance can get worse and may not be corrected. Same problem as in lead batteries. I just connect via bluetooth to my batteries whenever I'm approaching 100% SOC to verify that series pairs are balanced. FWIW - Victron advises against using battery balancers in systems such as mine where 12v are put in series to make 24v and then paralleled. I'm not sure why?

With regards to temp, my system doesn't have a "bank temp sensor" nor does Victron recommend one. High temp disconnect means that the BMS tells the chargers to stop charging when even one of the 24 total cells gets too hot per each cell's internal temp sensor. Note that charging is simply stopped - the battery is still connected.

The Mastervolt Alpha Pro 1,2,3 is controlled by a "reg-on" wire. That's how I have it safely stop charging if the BMS senses something awry. It required two Hella relays and a solid state relay - I wrote it about it in another post. I also installed a switch inline to turn off the alternator during long motoring sessions when I don't want to keep the batteries at 90%+. Very easy to do.

I honestly think if you're not living full time liveaboard, often away from shore power and you're willing to use the generator a lot, lithium does NOT make sense. It's a lot of brain damage and cost to get it right. It works for people with my use case and people like Garulfo (A54 with Mastervolt lifepo4 system for much longer than my 2 years) who when I asked him if his lazarette 230v breaker is working, he shrugged his shoulders and said, "I can't remember the last time I plugged in, so not sure." Not to put words in his mouth, but I'm pretty sure for him, he would never go back to lead.

--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Dean Gillies
 

Hi Alan,
Thanks for your contribution to the pro-AGM argument.

We've chatted about the benefits of battery balancing before and we are in full agreement about its value in a series-string based system. You may recall I had one series pair of AGM's which had become unbalanced about two years ago. I tried to recover them by individual charging and I was planning to install a balancer in early 2019, but 2019 was a busy season and I didn't get around to it, and I've been unable to return to the boat since then. On detailed testing before I left the boat in late 2019 almost all of my batteries were very low on capacity.  I don't know whether there is a causal link between the unbalance and the whole bank degrading.  I inherited the bank from the previous owner, and I know it was installed in 2015, but obviously I don't know what use/abuse the bank may have been exposed to before I bought in 2017.  This experience colours my thinking about the longevity of AGM batteries on the Amel boats, hence my expectation of 5 years.  My previous cruising boats have all had less complex DC systems, none employing 24V, but (lead-based) battery replacement every 5 years was not unusual.  Maybe it can be better, but I have not personally experienced that.

If I decide to stay with lead batteries for another cycle, I will definitely install the Victron balancer. At the moment I have 12x 12V AGM's organised as 6 strings with no interconnecting midpoints.  My plan would be to introduce interconnecting midpoints to create two independent strings of 3 + 3 parallel connected batteries.  This way I can use two balancers rather than needing six of them, whilst staying within the Victron recommendation that each balancer is able to balance 3x 200Ah pairs.

I like your idea of the alternator switch. I do have a 3-stage external regulator that changes from bulk charging to absorption mode at 28.5V, BUT it then holds 28.5 for a minimum 4 hours before changing to float at 26.5. Not the best if you are starting off fully-charged, but better than an alternator that sticks at 28.8V ALL DAY regardless !

It is an endless discussion as you say.  Given the Benefit/Cost differential I think my decision will be either "Evangelical" (Go Lithium) or "Logical" (Stay Lead) :-)

All the best
Dean
SY Stella 
A54-154