LiFePO4 vs FLA - The Real Deal

[ramblinrod]

Originally Posted by newhaul

where do you get the part about everyone changing boats every 5 years.

Read again, "the average boater".

"Everyone" was your word not mine.

Additionally, I suggest you recheck your numbers.

Your number is way too high for "most".

It happens on occasion, but it is very very rare to find a 40 year old single owner boat, and quite rare to find a 40 year old, 2 owner boat.

So if these circumstances are so rare, it is highly unlikely "most" of your customers have owned their boats for 20 years.

Meanwhile, it is quite common to see someone sell a boat after only 2 or 3 years for a variety of reasons:

Health
Divorce
Spouse doesn't like it
Job change
Financial change
Want something bigger
Want something smaller
Too much work to maintain
Transition from sail to power
Transition from power to pontoon.
etc.

So this is why the average is about 5 years.

[newhaul]

Originally Posted by ramblinrod

Read again, "the average boater".

"Everyone" was your word not mine.

Additionally, I suggest you recheck your numbers.

Your number is way too high for "most".

It happens on occasion, but it is very very rare to find a 40 year old single owner boat, and quite rare to find a 40 year old, 2 owner boat.

So if these circumstances are so rare, it is highly unlikely "most" of your customers have owned their boats for 20 years.

Meanwhile, it is quite common to see someone sell a boat after only 2 or 3 years for a variety of reasons:

Health
Divorce
Spouse doesn't like it
Job change
Financial change
Want something bigger
Want something smaller
Too much work to maintain
Transition from sail to power
Transition from power to pontoon.
etc.

So this is why the average is about 5 years.

btw you said specifically people change boats every 5 years .so no you didn't state every but you did imply.
definitely different numbers mostly I'm sure to regional conditions. Here in the pnw boats almost outnumber people. Liveaboard lists are mostly 5 or more years long.

So I would be willing to bet its regional.

Btw I'm the third owner of my 1963 defender . My dad was the third owner of his 1966 Spencer sailboat and I'm the 4th. With good quality vessels it is quite common here.

But you still hadn't answered my query why do you push Fla so hard.

[ramblinrod]

Originally Posted by newhaul

is there actually a reason you keep pushing Fla over Lfp

Because there are a whole lot of people making wild claim in favour of LifePO4 and bashing FLA, and it is pretty much completely unwarranted.


If someone wants to buy LiFePO4 because they think it makes them "cool" I will gladly sell them some, after advising that in 95% of cases, they would be way better off with FLA.

No one system works for every cruiser or even the same boat for different cruisers.

Well, actually my recommendation works. ;-)

With 400 watts solar and 400 wind ( the smallest marine grade I have seen ) you will not go dead with a properly sized bank regardless of chemical makeup.

See. (So why pay 6 - 10 times as much for LiFePO4 that have to be shipped half way around the world, as one can for FLAs at the shop around the corner.

I'm still getting 4x life over Fla banks.

Then you are doing something wrong with FLA banks; probably chronically undercharging.

If you use my ratios, charged properly, the FLAs will last 5.

Your LiFePO4s are not likely to last 20. Be happy if you see 10.

So if the LiFePOs were only 50% more than FLA (they are much more but for arguments sake), then maybe, but a greater than 7.5 year break even is considered a pretty bad investment, especially if the LiFePO4 batteries are not "money-back" or "full replacement" guaranteed to the break even point. (They aren't).

[44'cruisingcat]

Certainly, how long you intend to own the boat is something to consider if you're thinking about lithiums. In fact I recently pointed this out to friends who need new batteries now, but will likely sell their boat in the next couple of years.

I'm pretty sure they'll be buying lead.

However, I do think having lithiums will add resale value to a boat. The likelyhood of not having to buy batteries all the while you own the boat must have some appeal.

[newhaul]

Originally Posted by ramblinrod

Because there are a whole lot of people making wild claim in favour of LifePO4 and bashing FLA, and it is pretty much completely unwarranted.


If someone wants to buy LiFePO4 because they think it makes them "cool" I will gladly sell them some, after advising that in 95% of cases, they would be way better off with FLA.

Well, actually my recommendation works. ;-)



See. (So why pay 6 - 10 times as much for LiFePO4 that have to be shipped half way around the world, as one can for FLAs at the shop around the corner.



Then you are doing something wrong with FLA banks; probably chronically undercharging.

If you use my ratios, and your LiFePO4 last 10 years, I assure you, under the same conditions, charged properly, the FLAs will last 5.

So if the LiFePOs were only 50% more than FLA (they are much more but for arguments sake), then maybe, but a greater than 7.5 year break even is considered a pretty bad investment, especially if the LiFePO4 batteries are not "money-back" or "full replacement" guaranteed to the break even point. (They aren't).

Perhaps you should study the aspects of Lfp with an open mind.
I don't push either the customer asks the questions and I answer with actual data not personal opinions. Show the data. I do

[44'cruisingcat]

Originally Posted by ramblinrod

Your LiFePO4s are not likely to last 20. Be happy if you see 10.

So if the LiFePOs were only 50% more than FLA (they are much more but for arguments sake), then maybe, but a greater than 7.5 year break even is considered a pretty bad investment, especially if the LiFePO4 batteries are not "money-back" or "full replacement" guaranteed to the break even point. (They aren't).

You do know that just because you say something doesn't make it true?

The fact is, many lead acid batteries only have a one year warranty. Some even have one year pro rata.

Doesn't mean they wont last well beyond 1 year. But they could crap out in 366 days....

A car I owned was 30 years old. Only had 1 year warranty though.

There's getting to be quite a few early adopters with 8 - 10 year old lithium banks. Enough to suggest it's reasonable to expect them to last at least that long with reasonable care.

[ramblinrod]

Originally Posted by 44'cruisingcat

Certainly, how long you intend to own the boat is something to consider if you're thinking about lithiums. In fact I recently pointed this out to friends who need new batteries now, but will likely sell their boat in the next couple of years.

I'm pretty sure they'll be buying lead.

However, I do think having lithiums will add resale value to a boat. The likelyhood of not having to buy batteries all the while you own the boat must have some appeal.

In my experience, comparing 2 equal boats with the exception that one had brand new bank of FLA and the other LifePO4.

A) Some would want the vessel with FLA because they don't know about or trust LiFePO4.

B) Some wouldn't care either and the boat with the prettier curtains would be picked.

C) Some may think having a LiFePO4 bank would be cool, and may pay pennies on the dollar spent.

D) Nobody but nobody is going to pay full price (no where near it) for used LiFePO4.

[daletournier]

Originally Posted by newhaul

is there actually a reason you keep pushing Fla over Lfp
No one system works for every cruiser or even the same boat for different cruisers.
With 400 watts solar and 400 wind ( the smallest marine grade I have seen ) you will not go dead with a properly sized bank regardless of chemical makeup. Btw even with Lfp it is still my recommendation to have a Fla start battery. Lfp dead start your engine and charge them back up . What's the problem.
I'm still getting 4x life over Fla banks.

I think it's healthy Rod presenting his argument and believe there is some merit to what he says.

As stated previously I believe next time around I'll probably be going the lithium route. Debates, discussions like this get me thinking more and learning more about the topic. Eg, I have learnt the expense can be less than I previously thought.

People stop listening to others views due to being to busy defending their own. This has happened on both sides here.

[44'cruisingcat]

Originally Posted by ramblinrod

In my experience, comparing 2 equal boats with the exception that one had brand new bank of FLA and the other LifePO4.

A) Some would want the vessel with FLA because they don't know about or trust LiFePO4.

B) Some wouldn't care either and the boat with the prettier curtains would be picked.

C) Some may think having a LiFePO4 bank would be cool, and may pay pennies on the dollar spent.

D) Nobody but nobody is going to pay full price (no where near it) for used LiFePO4.

And what exactly is your experience? Have you bought or sold many pairs of boats, identical in every way apart from the batteries?

I'd suggest that you havent.

[mbartosch]

Originally Posted by ramblinrod

For a full time cruiser, I recommend that first an energy analysis be performed to determine average daily consumption, at anchor and when underway.

Then, for every 100 A-hr of daily consumption, install:

- 200 A-hr of cheap FLA battery
- 200 W solar
- 200 W wind
- 40 A alternator

With this set up, you will have ample power.

Your FLA batteries will last about 5 years.

With this statement you confirm the basic problem with LA: one needs to grossly overprovision charging sources to make sure you can reach 100 % SoC regardless of the diminishing CAR of the LA batteries.
The setup you quoted would be capable of replenishing a multitude of the required 100 Ah, the rest of the charging sources potential is lost to Peukert and to the decreasing CAR of LA when approaching 100 %.
Hence the need for a wind generator: it is needed to provide near constant charging to the LA batteries. Without the wind gen I'd doubt this would fly with prolonged stays from the dock.

With LiFePO4 instead, you establish your energy budgets. Then plan charging sources to replenish daily use (+ some extra margin), that's it. Size battery to taste.
Practical proof that this actually works: http://www.cruisersforum.com/forums/...ml#post2704580

If you do not design your LiFePO4 system with reserve capacity, (A-hr rating twice average daily consumption), you may run out of power on days when load exceeds average or you screw up and fail to meet charging needs.

What was your word? Hogwash? 400 Ah bank, 300 Ah top daily use when cruising. Not a problem with LiFePO4, as mentioned, never went below 22 % on our cruise.

When the BMS shuts the batteries down, you will not be able to even light an LED anchor light.

Completely incorrect. You override the BMS (on my system that's a short twist of the BMS on/off switch which overrides the LVD for 60 s after startup) and one still can draw 1C or more current out of the bank. Enough time to start the engine. The LVC is designed to happen way before the bank is damaged, so even if an LVC is bound to happen, you can still use the bank in an emergeny (or "priority") situation.

However, this will not happen, since a 20 % SoC alarm from the coulomb counter will have alerted the crew long before this is bound to happen to start the engine for recharging.

And yes, I have checked actually accuracy of this system by bringing the bank down from 100 % SoC to LVC at the dock. LVC happened almost precisely at 0 % SoC displayed by the coulomb counter (actually a bit after 0 % was displayed).

[hzcruiser]

Originally Posted by 44'cruisingcat

BTW, I'm trying to make sure there's no hint of "agression " in my posts. Please let me know whether or not I'm succeeding.

You're doing extraordinarily well, if I may say!




(So far)

[CatNewBee]

This discussion is like chewing gum, it extends in many directions and there are a lot of claims, that simply are not true.

First, FLA banks, especially above 400Ah are built either by 6V or 12V blocks of smaller batteries, in series or in parallel, with their own problems. Because FLA set ups have no meaningfull BMS installed, they are vulnerable to various problems.

In serial installations there could be imbalances between the building blocks, if one block has a higher resistance than the others, what leads to overcharging the one block and slowly damading it (boiling the cells), while the other block get notoriously undercharged and degrade from sulphation. Thats the reason, you must change all batteries at the same time, regardless if there are some good ones among the bank.

In parallel set ups there are other problems. With FLA it happens that one plate simply corrodes and breaks up causing a cell short, or while charging, the lead rebuilts on some parts better than others and grows a spike causing a short cell. This battery gets hot, the shortened cell decreases the voltage of the battery, so all current from chargers and the neighbor batteries boils the remaining cells, the other batteries are discharged over the short cut and have more cycles than necessary according to your consumption. All batteries are slowly dying way before they would if used separately.

Mean life expectance of a FLA bank is always way below the life expectance of a single battery component, and you must throw out a lot of working batteries when it comes to replacement. With a well designed BMS you can early fix problems and also separate batteries when not charging / switching between the strings on discharge and teaming up on heavy loads. Then you can reach the advertized life expectancy. But this is not for free, it seems cheaper to replace all 4..8 batteries every few years.

The other direction was about capacity. you can indead replace a FLA bank with a given capacity by a LFP bank with 1/2 ... 2/3 capacity without experiencing any disadvantage in usable energy / changing your behavior. You will even have an impression of improvement, all systems will work better (less voltage drop) and charging will be faster and more efficient. You will experience the same "reserves" in similar situations.

But usually you will replace at least 1:1 introduce same capacity LFP for a given capacity FLA, what virtually upgrades your system to 30...50% more usable energy, you can cope with longer rain periods without recharging and enjoy longer stays at anchor without running a genny.

Some do the upgrade on purpose and double or tripple the capacity by the conversion using the same space an weight to bring the system and their life style to the next level. That is a bonus, and not really discussed in detail. LFP pays off on the long run, especially for liveaboards, where you not need a generator any more and solar or wind takes care of charging.

With everything electric on board (galley, watermaker, washing machine, A/C, freezers), we use in average 400...500Ah per day cruising our 40ft cat (hydraulic auto pilot, radar etc.) and 300...400Ah when anchoring, re-charged by solar. We can easily cope with some bad days without much charging.

[CatNewBee]

Our statistics for the last 4 weeks completely off grid cruising:

23541Ah drawn from the battery, (308kWh), 541kWh solar input (200kWh were consumed directly without going through the battery), deepest discharge was 600Ah so far - 0h generator time. Would not have worked with FLA batteries.

Battery has reached 100% SOC on 20 days, on 11days the solar system could not re-charge to full, longest period without going to full was 5 days in sequence, usually after 2 days the battery is full again.

[44'cruisingcat]

Originally Posted by hzcruiser

You're doing extraordinarily well, if I may say!




(So far)

Thanks for the feedback! I really didn't think I was being aggressive. Maybe my commas look like angry eyebrows? I'll try to cut down on them.

[44'cruisingcat]

Originally Posted by daletournier

I think it's healthy Rod presenting his argument and believe there is some merit to what he says.

As stated previously I believe next time around I'll probably be going the lithium route. Debates, discussions like this get me thinking more and learning more about the topic. Eg, I have learnt the expense can be less than I previously thought.

People stop listening to others views due to being to busy defending their own. This has happened on both sides here.

Sure, presenting an argument is fine. And in fact I agree that at US prices, it's difficult to justify lithiums in financial terms. The other benefits would have to be important to you as well.

But, to say that because lithiums CAN be charged in one hour means they MUST be, requiring huge additional investment in generator and battery chargers is frankly, stupid, and seriously reduces the credibility of the OP.

Add to that the claim that lithium battery banks need to be significantly bigger than the LA they replace.... well you really have to wonder...