42: Lagoon 42 and LiFoPo4 batteries

[ObiWanSand]

Dear Ladies and Gentlemen of the forum!

We are picking up our L42 in Les Sables in June

I was wondering if any of the (appearantly at present close to 200) owners of the boat have installed Li batteries? I am considering this, in spite of Lagoons indifference if not outright disencouraging attitude to this technology!

In fact the owners manual claims that the factory option 2000W Marinco Sinewave inverter, should only be powered by Lead Acid batteries!

This leads me to question whether there is a difference between 12VDC supplied by Lead Acid vs 12 VDC supplied by Li?

Each of the batteries I am considering have their own BMS, which I am assured will take care of the battery preventing over charge or excessive discharge of each battery.

Happy to hear any feedback on this little dillemma!

[PaulinOz]

Congratulations on the New 42. Do you know the production number of your boat yet?

From memory they may have sold well over 200 but they only just launched hull #100. so not quiet as big a sample as you may imagine to garner battery information from.

Forgetting the weight saving and the speed at which they can absorb a charge the cost still seems way out there to me.

Can only talk Oz prices 5 x 300 a/h =1500 amp/hr AGM bank currently $2,800 AUD (collected last week) weight 5 x 82 =410 Kg Max DOD 50 % = 750 a/h uasable

Victron LiFePO4 Battery 12,8V/300Ah - BMS $6235.00 AUD each
Bank of 3 = 900 amp/hr Max DOD 85% = 765 a/h usable at $18,705 AUD plus associated control equipment required. 171 kg

LiFePO4 meant to last 10 years. A new set of AGM every 2 1/2 years $11,200 still almost half the cost.

I would love to save 200 plus kg of battery weight, but I cant justify the cost to do so. That's all assuming the LiFePO4 have an effective life of 10 years. As the costs come down they will become more and more attractive though.

[ObiWanSand]

Thanx Paul !

Our boat is hull nr. 131, and we expect handover on june 6.

Yes...I do see your math, and to be honest I had actually decided to go Lead Acid, just to get som peace of mind on this issue. Plenty of other things to handle before we set sail in august!

The Victrons are certainly top of the line, perhaps they are worth the extra cost...? I got an offer recently that would come out to about 9,21 AUD pr. Ah. Nominal not usable ! I forget the brand name, I'll have to get back on that. That would also be ex VAT, which I can do since we are not bringing the yacht back to Norway.

That is a little less than half the price of the Victron batt that would come out at about 20,8 AUD pr. Ah (incl VAT though)

I am also intrigued by your housebank size. It is almost twice the size I am considering for our boat in usable Ah. Could I bother you for a short briefing on what your charging regimen is?

Part of my dillemma you see, is that I believe I could dispense with a costly hydrogenerator if I were to shift to LiFePo. The fast absorption rate of the Li batts may allow me to live on solar (2 separate sets nominal rate of 1160 W altogether), a backup 2000W petrol generator and engine use (250 A if running both engines)

My calculated DC power consumption under way at night is about 260 Ah, at anchor at night about 140 Ah. This will see our housebank (425 Ah usable) at about 50 % SOC in the morning, before starting engines for hotwater and charging while at sea. At anchor the SOC would be over 70%.

On a cloudy day with solar running at 60% efficiency would see about 390 Ah produced. Consumption at about 270 Ah during daytime underway. This would mean about a half hour with both engines running to balance the equation. (assuming that Li truly absorbs at the rate I am told!)

At anchor, even with solar at 60% should see the energy balance in black figures, about 130 Ah surplus energy without running engines.

That would be in theoretical terms, what it will be in practice remains to be seen of course.

Very grateful if you choose to share your thoughts on this!

brgds
Oddvar

[ObiWanSand]

By the way...

I just heard back from Marinco, they see no problem with their inverter being powered by Li.

They mentioned I should check the max charging voltage the Li batts could take, reminding me that the inverter's max voltage is 15V with a cutoff at 15,3 V +/- .5V

Could this not be handled by setting maximum charging voltage on our voltage controllers to say...14,8 V?

[ObiWanSand]

on second thought... that is to high for Li batts, but the principle should still apply. Right?

[BruceS]

From a LiFePO4 user ..... you forgot to mention how quick you can charge or discharge (use) these batteries.
At times I can charge in an hour where I used to do it in 5 hours.
They just suck up what you throw at them!

[Emerald Sea]

Originally Posted by ObiWanSand

on second thought... that is to high for Li batts, but the principle should still apply. Right?

Thats correct. But before you select a LiFePO4 supplier and related equipment, do check that these settings are available.

We went with a complete Mastervolt system and while expensive, their service and direct web connection to our system for all settings is first rate. Ive posted more on this into the LiFePO4 Design thread.

[Saltrun]

ObiWanSand,
If you get the gel battery option, you will get 4 AGM Exide 1350 120AH batteries. We just picked up our 42, hull64 in St Martin. This battery bank is pretty puny, and although we are frugal with energy usage, we know this needs beefing up. These batteries are not available here in the Carribean or in the States, but can be gotten in Europe. They are a long, slender battery, I can give you the sizes if you want. The cheapest way to upgrade the bank, would to be to add 2 of these, in the same box, just like the boxes that the factory uses. There is room in the starboard engine compartment adjacent to the house bank that already lives there. Put the solar controller in there, and it is an easy add on. This will give you 720AH of house batteries, or around 250 amps of useable power and be at 65% charge. Just use the batteries you are already purchasing with the boat for a year or two. Lithium is getting cheaper, and maybe it will come down more by then. Besides, adding a couple batteries should cost less than a grand, instead of 15 grand. Now you have money left over for the really important things... like maybe... a Disco Ball!
Chris
SV Disco Volante

[Maine Sail]

Originally Posted by ObiWanSand

By the way...

I just heard back from Marinco, they see no problem with their inverter being powered by Li.

I don't know why Marinco/Mastervolt would ever question the use of their Combi's for LFP when they sell LFP batteries...

Mastervolt has also reduced the max recommended charge voltage of their LFP batteries from 14.6V to 14.2V... Even this is far too high when using lead acid specific charge equipment, where the "CV/absorption duration" can not be adjusted well below 1 hour.

Unfortunately Mastervolt fails to address duration at CV in their manuals so folks will be still shortening the life of the MLi's by holding CV/absorption at 14.2V.

With LFP batteries it is not just a target voltage but it is also duration at target voltage (time @ constant voltage/CV). Even at 14.2V, if held long enough, will cause over charging, cell damage & reduced life of the LFP cells. Most lead acid charge equipment delivers a 1 - 4+ hour CV duration. This = BAD for LFP batteries. At the 1 hour end of an absorption cycle you can reduce charge voltage to 13.8V but even then the batteries are at 100% SOC in less than 1 hour so you're still over charging them. at the 4 hour end of the spectrum you're simply feeding them poison.

Mastervolt also suggests a float voltage of 13.5V (3.375VPC) and you DO NOT float LFP.. Heck just sitting at a 100% SOC, with prismatic cells, will cause a loss of capacity in the rage of 11% in a 1 year period. This is with ZERO charging just charged to full and left to sit. Now float them above the natural resting voltage and this only gets worse. This is what happens when you try to sell LFP into a lead acid mentality market and the marketing department wins out over engineering......

I have a $10k Mastervolt LFP battery in my shop as evidence that Mastervolts original 14.6V guidance (for a 12V battery double for 24V) was completely insane and murderous to the batteries. This battery came from a 100% Mastervolt system with no third party charge sources and was set up explicitly to Mastervolt's specifications and recommended settings..

If companies like Mastervolt, with large engineering departments, suffer from overt blunders with LFP, you can understand why Lagoon does not recommend it yet...

LiFePO4 batteries are NOT lead acid and we can't treat them as if they are, despite the market expecting it...

[casablanca]

We have a 420 and fitted 800AH Lithiums 2.5 years ago after finding that even the best AGM lead acid batteries don't do the job for full time live aboard usage.
No question that fitting Lithiums was the right decision. It is not just a cost issue. It is also a lifestyle investment. We can run 230V appliances whenever we want, toaster, hairdryer etc.,without concern about high discharge. House voltage is always high and no issues with low voltage drop outs. We can draw down to 24% before the protection system will cut in although we work with a higher margin.
But you need to invest in quality. Ours are supplied by Enerdrive located on Brisbane.

From our experience

Lead acid is ancient inefficient technology.
Even the best lead acid batteries don't handle repeated cycling, even when not deep discharged
Lead acids are good for maybe 2.5 years. (Live aboard usage)
Cost amortized over 10 years is about even.
If you buy lead acid, buy a big bank of lower cost batteries and budget on 2 year replacement.
If you are going to keep your boat buy Lithiums. If you don't expect to keep it buy lead acid.
No one uses lead acid in other applications these days!

[TravellingKiwis]

Hi ObiWanSand .... just wondering what you decided re batteries etc. Are you going Lithium and if so which make? Also, have you settled on amount of solar and mounting location? I am considering ordering a L42 and really interested in your plans / setup.
Thanks