LiFePO4 vs FLA - The Real Deal

[44'cruisingcat]

How fast do lead acid batteries charge for the last 10% or so? That's where the fast charging benefits of lithium are noticed. Your solar keeps charging in bulk mode, right up to full. With lead you get into absorption mode, and charging current gets cut way back. This would be even worse if you were using a generator or engine to charge. But even a 1kW Honda running a 50 amp charger will put get lithiums charged in a reasonable time frame, because they will accept the full 50 amps right up till theyre nearly full charged.

The fact is, having lithiums means you run your generator less, not more. With enough solar, you hardly run it at all.

[44'cruisingcat]

Originally Posted by ramblinrod

OK, so here's a direct comparison.

If you want a genuine direct comparison, look at people who have replaced lead acid batteries with lithiums. Inventing some fantasy scenario isn't a comparison.

[gmakhs]

Originally Posted by 44'cruisingcat

If you want a genuine direct comparison, look at people who have replaced lead acid batteries with lithiums. Inventing some fantasy scenario isn't a comparison.

Do people that use lithium use them in hard conditions?
Have they ever deal with a storm that the boat was flooded ?
Have they ever have to sail without a generator ??
Is anybody that got over 5 years of working lithium batteries ?

Even if you put so much solar how it behaves on a big storm ?
I have notice that.most people that add applications , Solars, and lithium staying mostly.anchor or in the marina ( no offense )
But to the sailor who sails on remote places , lithium is useless price wise and market wise .

[ramblinrod]

Originally Posted by 44'cruisingcat

If you want a genuine direct comparison, look at people who have replaced lead acid batteries with lithiums. Inventing some fantasy scenario isn't a comparison.

I thought the scenario posted was reasonable, all except for the cost of the LiFePO4s and the equipment and the fuel to take advantage of their faster charge rate.

But OK, lets look at your situation as you requested.

You charge your batteries slowly with wind and solar.

I can do that with FLA.

You charge your batteries by little generator at 50A.

I can do that with FLA.

Your batteries don't self-discharge.

Neither do mine, they are on solar float when not in use.

So what real benefits did you gain other than maybe 150 lbs weight reduction?

[fivecapes]

This just gets better and better

[44'cruisingcat]

Originally Posted by ramblinrod

I thought the scenario posted was reasonable, all except for the cost of the LiFePO4s and the equipment and the fuel to take advantage of their faster charge rate.

But OK, lets look at your situation as you requested.

You charge your batteries slowly with wind and solar.

I can do that with FLA.

You charge your batteries by little generator at 50A.

I can do that with FLA.

Your batteries don't self-discharge.

Neither do mine, they are on solar float when not in use.

So what real benefits did you gain other than maybe 150 lbs weight reduction?

So in your fantasy world, batteries must be charged in 1 hour?

And your batteries are on solar float at night too? Or maybe theyre quietly wasting amps....

I already went through this.

They're lighter.

They're more compact.

They're more efficient. Its like having 10% more solar panels.

They dont suffer from voltage drop under load, so electric appliances run better, and use less amps.

They don't mind being put to bed half empty.

They dont emit hydrogen.

They don't need water.

They operate at higher voltage, so every amp goes further.

[44'cruisingcat]

Originally Posted by gmakhs

Do people that use lithium use them in hard conditions?
Have they ever deal with a storm that the boat was flooded ?
Have they ever have to sail without a generator ??
Is anybody that got over 5 years of working lithium batteries ?

Even if you put so much solar how it behaves on a big storm ?
I have notice that.most people that add applications , Solars, and lithium staying mostly.anchor or in the marina ( no offense )
But to the sailor who sails on remote places , lithium is useless price wise and market wise .

Seriously? Do you have a boat?

If you're batteries get flooded by seawater, you're in trouble, regardless. You're certainly no better off with lead acid.

Almost all the RTW type race boats use lithiums. In all kinds of conditions.

Solar panels are fine as long as they're fitted properly. And the type of battery makes no difference to that. Although it could be argued that with lithiums you dont need as many solar panels.

Most cruisers spend most of the time anchored. If you stay in marinas you hardly need batteries at all. There's shore power.

Our friends lithiums are getting on for 8 years old, and performing like new. Our lead acid batteries were stuffed at 6 years.

[gmakhs]

Originally Posted by 44'cruisingcat

Seriously? Do you have a boat?

If you're batteries get flooded by seawater, you're in trouble, regardless. You're certainly no better off with lead acid.

Almost all the RTW type race boats use lithiums. In all kinds of conditions.

Solar panels are fine as long as they're fitted properly. And the type of battery makes no difference to that. Although it could be argued that with lithiums you dont need as many solar panels.

Most cruisers spend most of the time anchored. If you stay in marinas you hardly need batteries at all. There's shore power.

Our friends lithiums are getting on for 8 years old, and performing like new. Our lead acid batteries were stuffed at 6 years.

Stuffed at six years with this price difference you can buy them again and again and again , that why the OP has a great point .

About the flooding part , I am not saying the the lead acid will survive I am.saying that is easier to.replace it !!!

[44'cruisingcat]

Originally Posted by gmakhs

Stuffed at six years with this price difference you can buy them again and again and again , that why the OP has a great point .

About the flooding part , I am not saying the the lead acid will survive I am.saying that is easier to.replace it !!!

Certainly, if you search around for the mosr expensive lithiums you can buy, and compare them to the cheapest lead acid you can find, there's that argument.

But it's not realistic.

In my case, i looked for the best value for money AGMs I could find, and the best value lithiums.

The lithiums cost 50% more. (This is in Australia, apparently you can buy FLA batteries much cheaper in the USA. ).

So my lithiums have to last 9 years to break even financially. I fully expect them to go well beyond that. And in the meantime, they're simply better batteries.

[gmakhs]

Price for a a good agm at 100 ah is 150euro average quality and 300-400 a good quality ,
Price for 100 ah lithium starts from 900 euro that's more than 50% you can find cheap Chinese lithium with 200 euro at 100 ah but that's different story .

[44'cruisingcat]

At the time I got 400 amp hours of Winston batteries for $2800 delivered.

600 amp hour Remco AGM was around $2000 delivered.

Contrary to what the OP states, you can generally replace a lead acid bank with a somewhat smaller lithium bank, due to lithiums being able to be more deeply cycled, while still lasting many more cycles.

[daletournier]

Originally Posted by 44'cruisingcat

So in your fantasy world, batteries must be charged in 1 hour?

And your batteries are on solar float at night too? Or maybe theyre quietly wasting amps....

I already went through this.

They're lighter.

They're more compact.

They're more efficient. Its like having 10% more solar panels.

They dont suffer from voltage drop under load, so electric appliances run better, and use less amps.

They don't mind being put to bed half empty.

They dont emit hydrogen.

They don't need water.

They operate at higher voltage, so every amp goes further.

All this is true, so I believe, it makes them better BUT as I mentioned earlier dosent really make much difference in some scenarios (mine).

On my previous boat (33ft) the qualities you speak of would make a difference to my cruising, substantially. This is due to not having spare real estate. On my current boat the advantages are almost non existent due to having the room to carry enough lead (as John61 would say). Voltage sag very minimal, enough solar to put back in what's taken out daily (to cruising full), dosent really effect storage space, weight is irrelevant etc etc.

So one could argue the variables have to be taken into account when determining value.

If you can meet your needs comfortably without the expense, then why wouldn't you?

[44'cruisingcat]

Originally Posted by daletournier

If you can meet your needs comfortably without the expense, then why wouldn't you?

At Australian prices, lithiums will almost certainly work out cheaper. The difference in cycle life is greater than the difference in price.

So you get all the benefits, and save money too.

At the prices quoted from the US, I probably wouldn't have bought lithiums. As long as the prices quoted are comparing like with like, ie decent quality lead with decent quality lithium.

[daletournier]

Originally Posted by 44'cruisingcat

At Australian prices, lithiums will almost certainly work out cheaper. The difference in cycle life is greater than the difference in price.

So you get all the benefits, and save money too.

At the prices quoted from the US, I probably wouldn't have bought lithiums. As long as the prices quoted are comparing like with like, ie decent quality lead with decent quality lithium.

If it can be done for the same price, a better a price or not much more then it's hard to argue the lodgic.

I'm not 100% convinced on the life cycles quoted only because in the real world they are still relatively young BUT I certainly can't argue they won't last as claimed.

I'm hoping to not buy batteries for 5-8 years, buy then the "science experiment lol" as some call it will be well and truly mainstream, or maybe something better will be around and debated on Cruisers forum.

[ramblinrod]

Originally Posted by 44'cruisingcat

How fast do lead acid batteries charge for the last 10% or so?

Slowly.

That's where the fast charging benefits of lithium are noticed.

Wait a minute!

As long as the FLAs get fully charged every day, it doesn't make a real difference whether that was in 4 hours or 24 hours.

Your solar keeps charging in bulk mode, right up to full.

Ya. So? What good is a faster charge rate when it is not used nor needed?

With lead you get into absorption mode, and charging current gets cut way back.

Ya. So? We are charging slow with solar and wind. So FLA at some point will limit charge rate more. It doesn't matter one IOTA as long as the batteries get fully charged. So if the forecast in the morning is for light wind and little sun, start the engine (or genny up for an hour or two, bring them up to 75% and let the little wind and sun do the rest).

This would be even worse if you were using a generator or engine to charge. But even a 1kW Honda running a 50 amp charger will put get lithiums charged in a reasonable time frame, because they will accept the full 50 amps right up till theyre nearly full charged.

Ya. So? I understand it can. But in the real world is that a benefit? My FLA batteries are charged well up, every night. Charging the last 25% even 300% faster, wouldn't make any difference. Maybe I get to 100% only 80% of the time. They still last 5 years or more, and don't cost me 6 times as much. LifePO4 would have to last 30 years to break even. That's a poor investment. Do the weight savings justify? Maybe for a racer, when once they cross the finish line, if they won it was justified, regardless of cost.

The fact is, having lithiums means you run your generator less, not more. With enough solar, you hardly run it at all.[/QUOTE]


OK, but with a properly sized solar and wind charging system with FLA you hardly run it all. BTW, I don't have a generator. My batteries typically last 5 years or more.