LiFePO4 (LFP) battery poll

[twistedtree]

What are your current views on LFP batteries for your boat? Already have them? Switching to them at your next battery replacement interval? Will consider them at my next battery replacement interval? Have no interest in them?

 

[twistedtree]

What? Nobody has any opinion or plans for LFP batteries in their boat?

 

[rslifkin]

I'll definitely re-assess them at my next replacement interval. Not sure yet if I'll go for them though. My systems design works pretty well with AGMs without abusing them, so most of the benefit for LFP would be lower weight (which is attractive).

Whether or not I'll go for them depends on cost at the time, what changes I determine I'll need to make for charging or other systems, and if any other things I want to change or do on the boat push me in one direction vs the other.

Honestly, one of the biggest concerns I have with them that's so far un-solved is cold weather. I spend plenty of time working on the boat in below-freezing weather over the winter, so with current LFP tech, I'd need a way to isolate the house bank but still have DC power available while working. From what I know, current LFP tech cannot be charged below freezing, so I couldn't just do like I do now and plug the boat in and let the batteries float while working. They'd either be discharging from any DC loads I run (without warm enough weather to allow re-charging for 2+ months potentially), or I'd have to isolate them entirely.

 

[Tator]

We have owned LFPs for one year. Had to put off the install last summer due to health problem. I plan to install system-Victron inverter, 6 Lion Batts, Wakespeed- this May when I get back to Alaska.

Tator

 

[guy with a boat]

I’m switching the house bank to Battleborns later this spring. Our Lifelines are 8 years old and at reduced capacity.

The plan is to go with (6) 8D LFPs instead of the current (8) Lifeline 8Ds. My quick and dirty math says that gets me somewhere in the range of 50% more usable amps. We will add a 100a (24v) charger for a total of 350a/24v charging capacity and update the monitoring. Charging settings will be changed. Otherwise, no major electrical changes.

We run the gen daily for 240v loads anyway (and/or run the main), so having enough battery capacity to last for days isn’t useful or a goal for this project. I mostly want to avoid the long charging tail of the AGMs, increase useful battery capacity a bit, and hopefully get longer battery life before replacement.

 

[BandB]

What? Nobody has any opinion or plans for LFP batteries in their boat?

We were not driven to them by any comparisons or issues, just the builder of our most recent build insisted we couldn't mess up a new boat with old timey batteries, translating from a combination of English and Italian. In the future, if builders offer them, we'll get them. Otherwise, we'll stick to what builder offers as part of their standard offerings.

 

[Mako]

I would consider them for a new build especially if trying to operate without a generator.

However as B&B stated, all the shipyards I have discussed with offer FLA as standard, and these types of commercial shipyards (not custom yacht builders) do not like to vary their practices. I might be able to convince them to install a bank of industrial 2V batteries, which are my preference over old fashioned (but very inexpensive) 8D's.

 

[Bmarler]

i've got ten fla trojans in the center bilge for the house bank. i like them just for the weight. plus, anywhere you go you can get fla batteries if there's a failure.
good ballast, easy to replace, plenty of amp hours, cheap.

 

[danderer]

I'd consider them but would have to look long and hard at how'd I'd reconfigure for them.

- Current AGMs are in the ER. My impression is that Li wouldn't like being in an environment that can hit 50 degrees C. Could move them to the laz. Or could maybe make some major changes to my ER cooling though it isn't clear how.

- If the batteries are moved from the ER then the inverter should move too, so AC cabling moves. Also extend the cables from the 325A alternator ($).

So to me it is at least as much about how the batteries would fit in my environment as it is about their intrinsic characteristics.

The Degradation Behavior of LiFePO4/C Batteries during Long-Term Calendar Aging

 

[Ritchard]

I am just about to move off a medium-sized sailing catamaran that I installed LiFePo4 batteries in a year ago. For living on the hook and powering with solar almost exclusively, they were a great upgrade.

I am now looking at a lifestyle change and searching for a trawler. In my mind I thought Lithium would be one of the first upgrades, but now with further thought I'll have to see how I actually use the boat to see if the upgrade is worth it.

I would say that if the current FLA batts on any boat were near end of life, lithium is getting so cheap that it doesn't seem unreasonable to use them, especially since I live in the tropics and temperature is no issue.

 

[Simi 60]

Only early days for us but so far, best thing ever for us compared to previous AGM bank

LFP build worked out considerably cheaper than AGM replacement.
A bit of dicking around as I didn't buy drop one, but well worth it in $$ saved and end result.

 

[Gdavid]

LiFePo4 is a mature technology but properly integrating a LiFePo4 bank into a boat's existing electrical infrastructure isn't common knowledge yet. People who take the time to educate themselves and fully understand the capabilities and limitations are best suited to any new technology including LiFePo4.

These are anecdotal examples but probably a good representation:

A friend of my brother was an early adopter but from what I understand, not the most technically proficient. He sought out help and bought what should have been a nice system. Somewhere along the way between the consultant that was advising remotely, the boat owner and the local installer there was a lack of communication. The boat was a 36' sailing race boat (Mumm/Farr 36) with pretty extensive electronics. The only source of recharge for the house bank is the 12v alternator when away from the dock. For distance racing, they occasionally need to run the main engine in neutral to recharge without engaging the prop shaft. The external voltage regulator was not set up properly and it fried a high end alternator the first long race with the system. This left them navigating via hand held devices for the rest of the race, not the end of the world but frustrating for the skipper who went out of his way to upgrade his battery bank.

A different example is a friend with a 38' sailing cruiser, he researched intensively, ordered individual components to build a LiFePo4 bank dedicated to run an inverter for "luxuries" away from the dock, primarily fed by solar panels. He is pleased as could be with his system and now he is building a bigger system and in the process of pulling his diesel main to convert to an electric drive.

There is great potential but with the potentially high costs of large LiFePo4 systems, the stakes are high and mistakes are expensive, ultimately the boat owner needs to understand what is going into his or her boat..

 

[twistedtree]

Thanks to everyone who has taken the poll so far. Hopefully more will add their thoughts.


I have to say that the results are a lot different than I expected with much more interest in LFP than I anticipated.

 

[ksanders]

I will be considering them at my next replacement cycle.

During that time I will also be monitoring my lazarette temperatures to verify temperature compatibility as my cruising grounds transitions from sub arctic to tropical conditions.

 

[4arch]

I have to say that the results are a lot different than I expected with much more interest in LFP than I anticipated.

The thread title might be skewing the results somewhat as someone who genuinely had no interest in LFP may not bother to open the thread whereas if it had been titled simply "Battery Poll" it might have attracted a different slice of the userbase.

Also, I'd suggest there are a couple steps of choices missing between the bottom two responses. There are those who have already considered and rejected LFP as well as those who have a general interest in LFP as a technological innovation but haven't considered or have reservations about considering it for their boat.

 

[BandB]

The thread title might be skewing the results somewhat as someone who genuinely had no interest in LFP may not bother to open the thread whereas if it had been titled simply "Battery Poll" it might have attracted a different slice of the userbase.

Also, I'd suggest there are a couple steps of choices missing between the bottom two responses. There are those who have already considered and rejected LFP as well as those who have a general interest in LFP as a technological innovation but haven't considered or have reservations about considering it for their boat.

Always possible but to see 8 respondents who have made the move and 7 who plan to do so is still a sizable number and more than I expected as well. I think it's rapidly growing as more new boats with LFP.

 

[O C Diver]

I switched to Fireflys last fall, and that will probably be my last set for this boat. My take was that there is an advantage if you plan to own the boat for 7 or more years. My fear was manufacturers standing behind their warranties. Most of the models and a fair number of the companies haven't been around 7 years. My first set of batteries were Trojan T-105s. There are no unknowns about those batteries or the company. When I bought the Fireflys, same story. Known commodity with a good track record. I'm sure in the near future that prices will have bottomed out, we will know better whether to only buy the name brand ones or if the Amazon and Ebay ones are any good, and if the deep cycle numbers and retained capacity numbers are real.

Ted

 

[BandB]

I switched to Fireflys last fall, and that will probably be my last set for this boat. My take was that there is an advantage if you plan to own the boat for 7 or more years. My fear was manufacturers standing behind their warranties. Most of the models and a fair number of the companies haven't been around 7 years. My first set of batteries were Trojan T-105s. There are no unknowns about those batteries or the company. When I bought the Fireflys, same story. Known commodity with a good track record. I'm sure in the near future that prices will have bottomed out, we will know better whether to only buy the name brand ones or if the Amazon and Ebay ones are any good, and if the deep cycle numbers and retained capacity numbers are real.

Ted

And my strange economics. On something like batteries I will pay a good bit more than double, perhaps three times as much, for twice the longevity. There's the cost and effort to replace and the trouble of them showing their age at the most inopportune time. When it comes to parts and small items, I'm that way. I love LED because of the longer lives. I'd gladly pay for car batteries with lives longer than I intended to keep the car. Nothing worse than the morning you go to start the car and the battery has died.

 

[Blue Yonder]

Planning on getting 1440 a/h of Winstons on our new build, but I feel like I was dragging the yard outside of their comfort zone. They originally had recommended Firefly's but I wanted to go with LiFePo4 because of the weight advantage and I'm comfortable that the technology is mature enough at this stage.

 

[O C Diver]

And my strange economics. On something like batteries I will pay a good bit more than double, perhaps three times as much, for twice the longevity. There's the cost and effort to replace and the trouble of them showing their age at the most inopportune time. When it comes to parts and small items, I'm that way. I love LED because of the longer lives. I'd gladly pay for car batteries with lives longer than I intended to keep the car. Nothing worse than the morning you go to start the car and the battery has died.

I understand your logic, to a point. That's why I replaced my Trojan T-105s after 5 years. There was nothing wrong with them, they may have lost a little of their capacity (don't know). Could probably have gone 2 more years without issue. I rationalized that it was pretty likely that I would change them before selling the boat. So why not utilize the new ones that I was going to pay for anyway (peace of mind). Most importantly, I changed them at a time and place of my choosing as opposed buying something less between availability and location.

Regarding 3 times the price for twice the projected life, no thank you. I'd rather put a new raw water impeller in every year than find out the twice life expectancy one has died between Miami and the Bahamas.

If you're really worried about the car battery dying, change it when you take it in for routine service.

Ted

 

[mvweebles]

Two enthusiastic thumbs up. 800w solar plus 600 ah LiFePO4 on the boat last year. 340w solar 225 ah LiFePO4 on a camper van last year. I haven't used boat much, but total game changer on can

Energy density in such a small form and longevity means I reclaimed a LOT of ER space by relocating.

Cost is still a factor though diminishing. But it's pretty much the only downside. The upsides to LiFePO4 are considerable.

Peter

 

[Codger2]

Cost is still a factor though diminishing. But it's pretty much the only downside. The upsides to LiFePO4 are considerable.

I can't count the number of hours I've spent on researching LiFePo4 batteries as i am driving an all electric boat and plan on doing it until I'm 90.(9 more years to go.) My present battery bank consists of 16-6 volt AGM golf cart batts but when they die, LiFePro4s are going in. I haven't found one bad thing, other than price, about them in over 2 years of investigating battery chemistry.

 

[Scottwb96]

I'm currently running 8 Odyssey PC2150 AGM's (800ah) which really means I have probably less than 300ah considering age and DoD rates. Living in Seattle, not TOO concerned with cold temps. Although, I have seen some batteries designed w/ heating elements in them to offset the cold temp usage. I have also seen people fab up some cool heating options on some of the forums.
I have been slowly converting my charging system over to devices that will be more LFP friendly (dual WS500's, adding in the new Multiplus-ii soon). My biggest decision right now is drop-in vs. custom setup. Also deciding how large I will end up going. 400ah would basically give me the same usable ah I have today. 800ah would most likely be my minimum. 1,200ah is where I would like to be. lol, 1,600ah would be stellar!!!

 

[BandB]

Regarding 3 times the price for twice the projected life, no thank you. I'd rather put a new raw water impeller in every year than find out the twice life expectancy one has died between Miami and the Bahamas.

If you're really worried about the car battery dying, change it when you take it in for routine service.

Ted

I agree with you on impellers, but I've never had a warning or known how to predict the failure of a car battery. Always just failure to start.

 

[rslifkin]

I agree with you on impellers, but I've never had a warning or known how to predict the failure of a car battery. Always just failure to start.

Occasionally a battery will short a cell or have some other sudden total failure. But usually it's just diminished capacity over time. So you can test for condition, or if you're really observant, slightly slower cranking may be noticeable as the battery gets close to end of life.

 

[O C Diver]

I agree with you on impellers, but I've never had a warning or known how to predict the failure of a car battery. Always just failure to start.

With car batteries, there is a simple load test that's done to determine the health. Can be done when the car is in for routine maintenance. Normally a good quality car battery lasts 4 to 7 years, depending. Starting cars below freezing is much tougher as it takes a lot more cold crankig amps. Changing them at 3 to 4 years old would eliminate the no start.

My wife works outside Chicago. Going outside in January when it's dark and near zero to find the battery is dead, isn't worth the additional cost of changing it one year early!

Ted

 

[guy with a boat]

I agree with you on impellers, but I've never had a warning or known how to predict the failure of a car battery. Always just failure to start.

Change it at 3 yrs and you won't have another failure to start. Exceptions are defective battery and having a load left on when parked, which is hard to do in a newer car.

 

[syjos]

We have owned LFPs for one year. Had to put off the install last summer due to health problem. I plan to install system-Victron inverter, 6 Lion Batts, Wakespeed- this May when I get back to Alaska.

Tator

Hey Tator,

I recently sold to Keith, owner of Bluewater Ceora in Port Orchard, 5 Victron Energy LiFeP04 12.8V - 100Ah Smart batteries and assorted cables and accessories. You should know Keith, he organizes the Bluewater Rendezvous, when we had them.

He is installing them under the port settee. Nice feature about the LFP batteries is they don't leak or gas so no battery boxes and/or venting required.

Keith worked in electrical at Boeing so he is very knowledgeable about LFP's and their configuration.

If you have not purchased your LFP's yet, PM me for a quote. I can beat most internet prices and shipping is either free or reasonable, depending on the size of the order.

 

[BandB]

With car batteries, there is a simple load test that's done to determine the health. Can be done when the car is in for routine maintenance. Normally a good quality car battery lasts 4 to 7 years, depending. Starting cars below freezing is much tougher as it takes a lot more cold crankig amps. Changing them at 3 to 4 years old would eliminate the no start.

My wife works outside Chicago. Going outside in January when it's dark and near zero to find the battery is dead, isn't worth the additional cost of changing it one year early!

Ted

In NC, we had horrible luck with batteries. Testing didn't reflect the upcoming problems either so we just changed every three years before cold weather hit.

In FL, our pattern of use isn't conducive to battery life. We have three personal vehicles and they are all 9 1/2 years old and all have between 35,000 and 38,000 miles. We do get them checked and have someone who runs them weekly if we're gone. Also very high performance engines. Especially tough on them the last two years as we haven't taken any on our long trips but have driven a company owned Sprinter instead.

 

[rslifkin]

In NC, we had horrible luck with batteries. Testing didn't reflect the upcoming problems either so we just changed every three years before cold weather hit.

In FL, our pattern of use isn't conducive to battery life. We have three personal vehicles and they are all 9 1/2 years old and all have between 35,000 and 38,000 miles. We do get them checked and have someone who runs them weekly if we're gone. Also very high performance engines. Especially tough on them the last two years as we haven't taken any on our long trips but have driven a company owned Sprinter instead.

For anything we have that's not driven regularly enough I keep them on a float charge all the time while parked. Batteries last a long time that way.