Swapping AGM Batteries for Lithium Lifepo4

[Helmsman]

July 2024? I thought that was done in 2023. A member of ABYC needs to confirm.

The source I referenced this from is working on E-11. He stated that it would be out around July. He is a credible source.

I wouldn’t directly quote him without his permission, but certainly if someone else who is a member of ABYC wants to confirm, that would be great.

 

[SteveK]

The source I referenced this from is working on E-11. He stated that it would be out around July. He is a credible source.

I wouldn’t directly quote him without his permission, but certainly if someone else who is a member of ABYC wants to confirm, that would be great.

No Matter, just I thought this was discussed last summer as effective then.

 

[Helmsman]

No Matter, just I thought this was discussed last summer as effective then.

Thanks Steve, I think with the technology changing quickly that updates to the guidelines are probably following suit. We will see when the updates are published.

 

[twistedtree]

E-11 is indeed under review, but I can't say whether it will be out by July. It went out for public review late last year and that produced nearly 300 comments, so there is a lot of work to do.

That said, I can't think of anything that relates specifically to LFP battery systems. E-13 is the standard for lithium ion batteries, and that is not currently under review.

 

[SteveK]

TT thanks for the reminder that it was E-13. HERE is a link showing E-13 snippits

 

[Helmsman]

E-11 is indeed under review, but I can't say whether it will be out by July. It went out for public review late last year and that produced nearly 300 comments, so there is a lot of work to do.

That said, I can't think of anything that relates specifically to LFP battery systems. E-13 is the standard for lithium ion batteries, and that is not currently under review.

The E11 changes will affect the E13 policies also, based upon what I understood from the information that was shared. I could certainly be wrong about that, but don’t think I am. Anywho, we will see soon enough!

 

[twistedtree]

The E11 changes will affect the E13 policies also, based upon what I understood from the information that was shared. I could certainly be wrong about that, but don’t think I am. Anywho, we will see soon enough!

I may be missing something, but I'm struggling to think of anything that is up for possible change in E-11 that would impact E-13 any differently from how it might impact E-10 which is the standard for all other types of batteries (lead in practice). And even then nothing is coming to mind that would impact either in any significant way. Impact on E-13 in general, and LFP in particular is something thing I'm always on the look out for, but again, I might have missed something.

 

[SteveK]

AS a wet coaster I had not heard the name Jim Healy, but rather I know the names Nigel Calder and Jeff Cote. Of course there are many more gurus like them.

Here is an article from Nigel

 

[Delfin]

FWIW, what I have learned or decided after five years after swapping AGM to LFP is:

1. DC to DC chargers are a solution in search of a problem. If you have an internally regulated alternator (and why on earth would you have that??), then to keep it from frying as the LFP sucks up max output for hours a DC to DC charger will throttle alternator demand so it doesn't burn out, but that negates the main advantage of LFP - rapid charge time. You want to be able to sock it to the batteries, which means an externally regulated high output alternator de-rated so it never overheats. In my case, that's a 25% of max output de-rating. Zero problems after five years.

2. Insurance companies, with one exception that I know of, couldn't care less if your boat has LFP. If you decide to DIY the installation and make a hash of it, your insurer might deny a claim, but that would be true whatever battery chemistry you install. You can burn a boat down with LA batteries quite easily, and LFP is safer than LA in any case, assuming both are installed correctly.

3. You can certainly start your engine with LFP, ASSUMING the battery you purchase is internally wired to handle the current flow. As Rod Collins has pointed out, some assemblers of LFP use whimpy internal cabling that won't handle the current demand. I have Lithionics LFP that are robustly wired and never give a thought to whether I am starting the CAT 3306 with my LA starter bank or LFP house bank.

4. You can have two separate chemistries in two separate banks if you like, with the same charging system handling both. In my 24v case, a 225 amp LA starter bank and a 600 amp LFP house bank. The settings on the external regulator are as follows:

- Bulk, 29.2 vdc. This because my Lithionics batteries trigger cell balancing at that voltage.
- Absorption, 29.2vdc for 5 minutes.
- Float 26.8 vdc

The LA bank receives exactly the same charging regime, and I had the same LA bank that was already a couple years old using that regime up until I replaced it last year.

5. Most of the angst over LFP seems to be related to people wanting to be able to set up their system and have it automatically managed. LFP doesn't like high voltage floating, so TT has pointed out that the solution is to just set the float voltage low enough that the LFP is happy. I chose to simply switch between LFP house and LA starter bank depending on the situation by using the usual rotary batter switch. The different use cases are:

- At the dock, the LFP is offline via the BMS on/off switch and the LA bank is online and receives the float voltage.
- Underway towards an anchorage, LFP is online receiving charge current until full, then I switch on the LA starter bank and turn off the LFP, so charge current is now going to the LA bank.
- At anchorage, the LFP bank is online, and the LA bank is offline. I then recharge the LFP at 180 Ah until full using the 100 Ah charger in the Trace inverter supplemented by three Sterling chargers. We're energy hogs, so burn around 300 Ah @ 24 vdc per 24 hours, so we recharge in 90 minutes. I could wire a timer on the NL genset to run those 90 minutes, but choose to just set a timer that lets me know to shut down charging. The LFP batteries still have 98% of capacity after five years and thousands of miles cruising.

The entire modification to my system pre-LFP was to remove the battery combiner between starter and house banks, add the Sterling chargers to take advantage of the rapid re-charge of LFP, and twiddle the charge settings on the Balmar MC 624 smart regulator to suit LFP. That's it.

 

[Brooksie]

If I were thinking of doing such a swap, and having had the experience of pulling people off a burning boat at sea, this is all I would need to decide:


More than 3.7 million cars that are currently on the road have a "park outside" recall, according to recent data from Carfax.

That's a 40% increase in cars with those recalls nationwide since May 2023. The number of cars with park outside recalls in some areas nearly doubled.

In Atlanta, for instance, there were 113,000 cars on the road with park outside recalls in January. That's up from the roughly 64,000 vehicles reported in May 2023.

California had 368,000 cars with park outside recalls on the road as of January. About 189,000 of those were concentrated in the greater Los Angeles area. It's a staggering jump from the nearly 93,000 cars with those recalls reported in the area in May 2023.

These figures, according to Carfax spokesperson Mike Lavigne, account for cars that have had a recall but don't have a fix yet and cars that have fixes available, but car owners haven't brought them into the shop yet.

Hyundai Motor America and Kia America issued park outside recalls for more than 3.3 million vehicles in September due to the risk of fire, according to the National Highway Traffic Safety Administration (NHTSA).

In June 2023, Lincoln issued a park outside recall for over 142,000 cars due to the same fire risk, warning owners to park "outside and away from structures and other vehicles until the recall has been remedied," the NHTSA said. That warning came just one month after Chrysler issued a park outside recall for certain Jeep Cherokee vehicles, due to the risk of fire.

"The park outside recall is one of the most rarely issued recalls by the National Highway Traffic Safety Administration," Lavigne said. "It doesn't come around every day, and they're considered one of the more dangerous recalls because of the hazard of fire."

It's particularly concerning because this warning doesn't just apply to cars that are in operation but while they are off and parked in someone's garage or near another vehicle, Lavigne explained.

It's scary because something "could happen with no outside interference or any human interaction," he added.
The top 10 cities with the most park outside recalls as of January:

Los Angeles: 368,298

New York: 155,501

Atlanta: 155,343

Dallas-Ft. Worth: 334,524

Chicago: 144,440

Philadelphia: 171,951

Phoenix: 104,247

Washington, D.C.: 2,843

Houston: 334,524

Orlando-Daytona, Florida: 334,013

 

[guy with a boat]

Brooksie,

The subject of this thread is Lifepo4 batteries, which are a different chemistry than what is used in cars.

Fire on boats is scary, but we don’t need to stop using all batteries because some other kind of battery in some other application has increased fire risk. A properly installed LFP system is arguably safer than a lead acid system.

The devil is always in the details, and there are some system differences due to the characteristics of LFP. Faster charging and increased capacity put greater strain on charging and distribution systems, but there is no great mystery to building a safe system. Failing to install intelligently (LFP or FLA) can result in overheated conductors which increases fire risk. We can’t blame the battery for improper installation.

The number of credible, verified reports of boat fire originating in properly installed LFP batteries is approximately zero.

 

[Delfin]

One of the most persistent errors about LFP batteries on boats is the insistence on confusing different lithium chemistries and point to car fires as a reason not to use LFP on a vessel. Since those car fires happen with Lithium cobalt, Lithium manganese, Lithium nickel manganese, etc. chemistries and not Lithium iron phosphate, those comparisons are pointless.


If one is interested, this link explains the differences: https://dragonflyenergy.com/types-of-lithium-batteries-guide/


Note that one of the disadvantages of LFP is its low 'energy density' compared to other chemistries, (which is why they're generally NOT used on cars) offset by their 'thermal stability' (i.e., they don't burn real good) and 'safety.'

 

[folivier]

The electrolyte in LiFePO4 batteries will not burn, it will smoke but not burn. As others have said it is not the same chemistry as used in LiPO batteries.
Years ago there was a video showing someone had directly shorted the terminals on a LiFePO4 battery and watched as it smoked, the case bulged, and never caught on fire. The recommended procedure in a direct short with LiFePO4 batteries is to douse them with water.
When I built a 1000 amp hour battery using Winston cells one of them came in leaking. Before I sent it back I collected some of the electrolyte and used a torch to try and ignite it. Didn't burn, just smoked.

 

[tiltrider1]

Brooksie, you made a similar comment in post 31 and were countered with the same chemistry lesson in post 34. Are you Trolling us?

 

[SteveK]

Brooksie, you made a similar comment in post 31 and were countered with the same chemistry lesson in post 34. Are you Trolling us?

Maybe mentioned before but Tesla is moving towards LifePO4 batteries. That is another endorsement.

 

[Mambo42]

I know there is a boat (sailing catamaran on youtube) that has installed a battery bank of a crashed Tesla in their boat. They actually installed water cooling as well, so I had the idea it was all safe.
Then I started reading up on Lithium ion and realized that you should never ever put a battery bank (lithium ion) into a boat after it had been in a crash. The risk of getting into a fire is simply too big.
I know the amount of fires, compared to the amount of cars our there, is still marginal, but the problem is I don't hear too many gasoline or diesel powered cars catching fire out of the blue.
So lithium ion would be a no go for us and am even getting second thoughts about our bicycle we just bought. Saw a video of a fire that happened on a 72' vessel in Key West. They had a bicycle battery, dropped it by accident in the water, did not dispose of it and when they started charging it the battery went up in flames, including the boat. A woman and her dog died in that fire. I could not help but thinking 'what if that would be us at night, on anchor' ? Would we just die in our sleep or would we be able to jump off the boat ?

I do have LiFePO4 onboard, 1400 Ah and am not worried at all. I know those are completely safe, they will not be the cause of a fire. That does not mean I cannot have an electrical fire, because I can always have faulty wiring or what I had last year: 'a connection that was not tight anymore'.

As for charging via the alternator. If you have an external regulator, like eg the WS500 you can maximize the Amps the alternator will supply, so you can set it to charge at eg 70 or 80 % of alternator output, thereby not overheating the alternator.

Changing the complete electrical system was an enormous investment and I understand it is not for everyone, but for me, after I make the final calculation, it still beats having to run the generator almost 24 hours per day.

 

[Brooksie]

Brooksie, you made a similar comment in post 31 and were countered with the same chemistry lesson in post 34. Are you Trolling us?

No trolling intended.

Glad to hear auto manufacturers don't know what they are doing but boaters do. I feel safer already.

 

[Mambo42]

No trolling intended.

Glad to hear auto manufacturers don't know what they are doing but boaters do. I feel safer already.

It is not that car makers don't know what they are doing, they know it very well. They need a battery with a lot of punch, i.o.w a lot of Kw and Lithium Ion can do that. LiFePO4 delivers roughly half to 1/3 of the Kw for the same amount of weight and that is why you won't find LiFePO4 battteries in a car.

But, since Lithium Ion has some short comings insures don't want to see those type of batteries on a boat and I can understand that........I also don't want them on my boat.

 

[Delta Riverat]

The AGM to LiFePO4 swap will be done on my boat soon. I have (2) 4D AGM made in 2017 that don't have much left. Going in will be (2) 300 AH Li Time with UL rated 200A BMS.

Just have to make sure to isolate the FLA starting batts from the house lithium ones and adjust regulator to not strain alternator. Boat already has one alternator for house and one for starts.

 

[Iggy]

No trolling intended.

Glad to hear auto manufacturers don't know what they are doing but boaters do. I feel safer already.

I am going on my 3rd year with LiFePO4 batteries for the house bank. Did I use fuses, yes! Did I up the size of my cables to take more amps than needed, yes!
Did I do my homework in changing how the batteries are being charged back up, yes! Did I talk to the battery and charging support people, yes!

After adding a shunt to monitor the whole house back and the ability to Bluetooth into each battery. I am happy to say my house bank is working batter than I would have thought.

People need to be educated to new technologies. Reading your post reminds me of watching the History Channel when electricity was wired into home in the late 1890s. People were scared of it. Today we can't live without it!

 

[slowgoesit]

But, since Lithium Ion has some short comings insures don't want to see those type of batteries on a boat and I can understand that........I also don't want them on my boat.

The problem some people have run into (including us) is that some insurance companies will not insure ANY chemistry of Lithium batteries.

We ran into that, early Feb of this year (2024), when we went to switch to our "Offshore Policy", thru Jack Line, that would taken affect from Acapulco, MX, down through the Panama Canal, and then on to Florida. Everything was set, fair rates, good coverage, then when it got to boat particulars and they asked what type of batteries . . . . I said LiFePO4, and FULL STOP, "Sorry, we don't insure ANY Lithium chemistries!" was the reply . . . .

Not sure if this policy is going to change with their having done away with the Jack Line and rolled it up with Markel . . .

We ended up going with a policy that required an immediate survey, was half again as expensive, for 20% less insured value, deductible went from less than $5k to $24.5k, no coverage for dinghy, very little for personal property, with a company that I have no confidence will pay off in a claim . . . just because we have LiFePO4 installed.

Our installation is NOT "drop-in". We installed 1,200 ah of Dragonfly LiFePO4 batteries with integral BMS, new Victron Inverter Charger set to LiFePO4 batteries, new Balmar 210 amp, high output alternator with external regulator (derated to 60%, or 135 amps) set to LiFePO4, new Victron Battery monitor, and Cerbo GX, ALL new marine 4/0 wiring, proper fusing, containment, meeting or exceeding the latest ABYC recommendations . . . . didn't matter.

Until these insurance companies get their heads out of their . . . . cubicles, and educate themselves on actual risk of different Li chemistries, we're at their mercy . . . .

We've had our LiFePO4 for two years, 8,000 miles, and almost 1,600 engine hours now of full time cruising.

We've had lots of minor problems with the boat, but nary a problem related to the LiFePO4 install. It's been as problem free as anyone could wish for!

Hope your LiFePO4 installation and operational experience mirrors ours, and you are as happy with it as we have been!


Edit: Our main engine start, as well as our auxiliary engine start are totally independent from the LiFePO4 install. The main is 24vdc, (two new sealed 8d FLA batteries) with a engine driven generator and a 24vdc charger driven off of 120vac power. The aux engine start battery is 12vdc (one 12vdc) charged off of the aux engine alternator only.

 

[Delfin]

No trolling intended.

Glad to hear auto manufacturers don't know what they are doing but boaters do. I feel safer already.

With respect, that is the logical fallacy of the 'either/or' argument - Either the different Li chemistries used in cars and boats are equally dangerous, or car manufacturers don't know what they're doing since they use a less safe chemistry than boaters.

The third alternative you ignore is that cars care more about weight and speed of charging than vessels, so have to use the chemistries that feature those characteristics, even when less safe than heavier, slower charging chemistries like LFP.

Perhaps stop digging.