The LiFePo4 Revolution!

[jviss]

I have been a bit of a battery nerd for a long time, even though I don't know as much as many here on this forum. I have come to a conclusion about the emerging LiFePo4 batteries. I think I can safely say:

LiFePo4 batteries are the most significant development in RV's and boats in over 100 years.

When you look at capacity, weight, speed of charging, and storage considerations, LFPs are revolutionary.

The technology is still evolving, in terms of accessibility to yachtsmen, since technology aimed at this relatively small market evolves slowly. But, it is coming. Cells are available at ever-decreasing prices (from Chinese suppliers). Battery management systems are becoming available at reasonable prices. But (as far as I can tell) there are precious few or no systems yet available designed specifically for yachtsmen that include all of the features that one would reasonably want and expect.

I want an LFP system on my boat! I have been trying to learn and absorb as much as I can about the batteries, the BMS's, and related components. I'm developing my own "requirements document," and searching for systems that may satisfy it.

For this reason, I'm asking my fellow forum members, and @Phil to support the inauguration of a sub-forum dedicated to the topic of LiFePo4 batteries and systems.

Thank you,

jv

 

[dLj]

Are you looking for a category under "Featured Contributors"?

Are you asking to be the "lead" in that area?

I'm just not sure of what your ask is.

dj

 

[Stu Jackson]

Wouldn't it be considered an evolution?

 

[BigEasy]

When you look at capacity, weight, speed of charging, and storage considerations, LFPs are revolutionary.

At 5x the cost of lead acid batteries and possibly 2x life expectancy that is a value analysis deal breaker. Costs would have to substantially decrease for me to be interested. Weight saving in not much of a consideration for me. Finally, I am not interested in Chinese batteries!

 

[dLj]

At 5x the cost of lead acid batteries and possibly 2x life expectancy that is a value analysis deal breaker. Costs would have to substantially decrease for me to be interested. Weight saving in not much of a consideration for me. Finally, I am not interested in Chinese batteries!

I've seen cost/benefit analyses that are well done that show how the monthly cost is actually lower for the LiFePo4 batteries than the best lead acid competitors. I'd have to look up the most recent work I've been looking at to post here but it's not at my fingertips.

as far as Chinese batteries - look at battleborn - US made and top of the line batteries! Excellent batteries!

Battle Born Batteries | Reliable Lithium-Ion Batteries

At Battle Born Batteries, we specialize in top of the line LiFePO4 lithium-ion batteries. Get out there, stay out there!

battlebornbatteries.com

dj

 

[jviss]

At 5x the cost of lead acid batteries and possibly 2x life expectancy that is a value analysis deal breaker. Costs would have to substantially decrease for me to be interested. Weight saving in not much of a consideration for me. Finally, I am not interested in Chinese batteries!

"Value analysis deal breaker." What does that even mean? What parameters are you comparing? With lead acid, if you don't keep them fully charged in storage they turn to junk. And, it's not 5x the cost, unless you are talking about junk supposed deep cycle batteries from Costco. For good, deep cycle batteries from Trojan, et.al, you're talking maybe $500 for 230 Ah capacity when new; they must be carefully managed to maintain that capacity, and seldom are. For a little more money you can gat an LFP at slightly more capacity that has much more usable capacity and none of the storage worries.

 

[Davidasailor26]

At 5x the cost of lead acid batteries and possibly 2x life expectancy that is a value analysis deal breaker. Costs would have to substantially decrease for me to be interested. Weight saving in not much of a consideration for me. Finally, I am not interested in Chinese batteries!

From a cost standpoint - You could get a 100AH 12V BattleBorn for $800. A 200 AH 6V Trojan T105 GC2 is about $190, but between the fact that the GC2 is 6V and the fact that you can only use 50% of it compared (vs. ~80% for LiFePO4) you'll need 2 T105's to have equivalent capacity as the BattleBorn (ok, 2 GC2's is a little more, but close). But then the Trojan is expected to get about 1600 cycles (or maybe 1200 depending on what you read), but the BattleBorn is rated for 3000-5000 cycles, so at least twice the life. So for truly equivalent capacity over time you'll need about 4 T105's to match the single BattleBorn. There's some rounding errors there so the GC2's might be a little cheaper, but it's not that far apart.

Beyond the cost, the GC2's are also 62 pounds per battery, so you'd need 120 pounds of GC2's to equal 31 pounds of LiFePO4. There are con's to the LiFePO4 too, like the need to figure out how to not fry your alternator, but those are pros and cons you can weigh.

 

[Stu Jackson]

Lithionics OPE-Li3 Marine Lithium Battery System | Bruce Schwab - Ocean Planet

This is the safest, most reliable, and easiest to install marine lithium battery system available. Years of manufacturing experience and patented technology.

oceanplanetenergy.com

 

[BigEasy]

"Value analysis deal breaker." What does that even mean? What parameters are you comparing? With lead acid, if you don't keep them fully charged in storage they turn to junk. And, it's not 5x the cost, unless you are talking about junk supposed deep cycle batteries from Costco.

Primarily cost vs life expectancy. The "junk" Duracell batteries from Sam's club, that I recentlly replaced lasted 8 years at a cost of $200 ea for Gp 31 100 amp capacity. Compare that to LiFePO4 at a cost of $800 to $1000. that may last for 10 years ( 3 year warranty). No thanks.

 

[dLj]

Primarily cost vs life expectancy. The "junk" Duracell batteries from Sam's club, that I recentlly replaced lasted 8 years at a cost of $200 ea for Gp 31 100 amp capacity. Compare that to LiFePO4 at a cost of $800 to $1000. that may last for 10 years ( 3 year warranty). No thanks.

I don't disagree with lead acid batteries well maintained can last a lot longer than often folk experience. You obviously are one of those that does that. Clearly from what you are saying, LiFePO4 batteries aren't worth the upfront costs for how you sail, use your batteries, and take care of your batteries. Just a FYI, I actually tend to get 12 to 15 years out of good lead acid batteries so your 8 years would not make me happy. If I screw up and don't stay on top of my battery care - then I won't get that kind of service - but I consider that on me, not the batteries.

I am looking to move onto my boat and begin relying much more on my batteries in daily life. Knowing what I do about what it takes to properly care for lead acid, I'm going to move to LiFePO4 batteries for my fundamental storage system, then run lead acid batteries for my winch, bow thruster and engine start battery. I'll end up with 3 lead acids, and likely 2 large capacity LiFePO4 batteries (or 4 smaller capacity batteries). I'll use these to maintain the lead acid batteries as well as run my house power needs.

I do, however, object to mis-information in the support of the system you've chosen. The battleborn batteries come with a 10 year warranty, not the 3 years that you have stated above. And they are often being seen to last 15 to 20 years.

dj

 

[BigEasy]

DLJ,
For your application, living aboard, perhaps LiFePO4 batteries are worth the cost. For a full time cruiser, I could certainly understand justifcation for LiFePO4. Again, it comes down to value analysis/value engineering; getting the most bang for your buck. For me, an occasional coastal cruiser with the remaining time on a dockside charger, it is not cost effective. The 3 year warranty info that I discovered was for a West Marine Relion LiFePO4 battery, not the Battleborn battery. BTW, a West Marine Relion Gp 31 is $999 wtih a 3 year warranty.

 

[Daveinet]

Lead acid make great additional ballast. LifePO4 is really a battery that has developed a reputation, but there are better batteries for cheaper cost. Its just that we trust LifePO4, the other types of batteries, not so much, as the sea of types of Li-ion prevents any one brand or make from standing out. If one could retitle this thread, I think it would be fair to claim that hoover boards Are the most significant developement in the boating and RV industry. Everyone knows about the hoover boards that caught fire without warning. That has steered the reputation towards LifePO4, as it had the reputation as a durable battery that could generally be trusted. The Chinese manufacturers all went to LifePO4 and promoted it heavily. As a result, LifePO4 was the stand out with a solid reputation, based on Chinese marketing.

 

[jviss]

Tesla announced they are going to LiFePo4.

Tesla switches all standard-range vehicles to LiFePo chemistry

 

[jviss]

At 5x the cost of lead acid batteries and possibly 2x life expectancy

Where did these numbers come from?

For me, an occasional coastal cruiser with the remaining time on a dockside charger, it is not cost effective.

Yes, sure, if you're plugged into the dock all the time and you keep your battereis watered, or otherwise properly maintained, they will last indefinitely. But if you are really using them, as in cruising anchorage to anchorage, or you're on a mooring, they won't last as long. Not being at a dock they will almost never be fully charged, which will lead to sulfation, reducing capacity and life span. Fully charging a bank is tough with the engine and even solar. Among the great advantages of LFPs is that they are fine sitting at a partial state of charge: no damage or degradation. I have had a terrible time trying to maintain my batteries, and as a result, I don't get much life out of them.

Note that for the same Amp hour rating, there is really much more useable capacity in an LFP. I estimate it to be about 30% more. And, since LFPs are fine at partial states of charge, I can charge them quickly to 80% or so, at much higher charging rates than are recommended for lead-acid. So, an hour instead of 4 hours for a 200Ah bank.

I said revolutionary instead of evolutionary because the evolutionary trajectory for lead acid, from Babylonia before the Christian era, to SLA, to AGM just ends, and LFP plots an entirely new trajectory, being the first chemistry departure from lead-acid that's safe for boats, and half the weight at 30% more capacity, and much easier care.

As for cost, as an example, you build a 265 Ah total capacity, 4S2P array with a basic BMS for less than $500. My two Trojan SCS200 115Ah FLAs cost $473 plus tax.

LifePO4 is really a battery that has developed a reputation, but there are better batteries for cheaper cost.

Please tell me about them!

 

[cagreen75]

Although I am not an expert by any stretch of imagination, I think that regardless of which battery type you use it is very important to not discharge them any more than necessary. For example, if you have AGM batteries (we do) it is common knowledge that they can be discharged to 50%. My question is why would you want to do that. It makes sense to me that the closer you keep the batteries fully charged the longer they will last. We all know that is not possible, but if you install charging systems like solar and/or wind to generate power to charge batteries you can keep the battery bank discharge at a minimum. The point is if you install a charging system that is sufficient to handle the most common loads you can indeed keep your batteries near fully charged while you are not connected to shore power. I know this works as we have done this on our boat. We have installed solar panels that are sized to handle all the common loads we have while sailing and the alternator typically tops off the battery bank at the end of the day when we motor into an anchorage or marina. When anchored out overnight the batteries are typically discharged down to around 80%. In the morning when the sun comes up the solar panels charge the batteries back up to nearly a full charge during the day. With this system, we can stay on the hook for days without excessively discharging the batteries. My thought is that when you think about installing a battery system that will suit your needs you also need to install a charging system that will not only charge the batteries but will also cover all of the typical loads that you have on the boat while disconnected from shore power. Doing that will keep your batteries closer to fully charged and I think that will make them last longer. The bottom line is, just because battery manufacturers say you can discharge your AGM batteries down to 50% does not mean that is a good idea. Of course like I said I am not an expert and there is no such thing as a perfect system, but I think that installing a battery bank without a charging system that minimizes the load on the batteries is a bad idea.

 

[dLj]

Yes, sure, if you're plugged into the dock all the time and you keep your battereis watered, or otherwise properly maintained, they will last indefinitely.

Not technically correct. Lead acid batteries will degrade over time just due to the passage of time. There are mulitple reasons for this, but the first one is that in essence you cannot let a lead acid battery just sit there - it self-discharages..

Lead acid batteries do not last indefinately under any circumstances of usage.

Among the great advantages of LFPs is that they are fine sitting at a partial state of charge: no damage or degradation.

This is one of their big advantages. The chemistry of the battery does not support sulfation, the primary cause of lead acid batteries degrading.

dj

 

[jssailem]

Those OceanPlanet Energy Battery Prices sure look rich.
Maybe those are Canadian Dollars...
***Battery models change often, prices subject to change without notice****
Lithionics Lithium Batteries 12 Volt LiFePO4 (12.8V nominal)

Case/Size	BMS	Model	Capacity (Ahs)	Capacity (kWh)	Weight	Price	General Notes:
G31 12.5” x 6.5” x 8.5”	Internal	12V130A-G31-LRBM8	130Ah	1.6kWh	34lb	$1679

OPE Battery Pricelist

OceanPlanet Energy Battery Price List ***Battery models change often, prices subject to change without notice**** * = New Models! Lithionics Lithium Batteries Lithionics 12 Volt LiFePO4 (12.8V nominal for 12V systems) (**Can be used in series for 25.6V & 51.2V systems) Case/Size BMS Mo...

docs.google.com

​

 

[dLj]

Although I am not an expert by any stretch of imagination, I think that regardless of which battery type you use it is very important to not discharge them any more than necessary. For example, if you have AGM batteries (we do) it is common knowledge that they can be discharged to 50%. My question is why would you want to do that. It makes sense to me that the closer you keep the batteries fully charged the longer they will last. We all know that is not possible, but if you install charging systems like solar and/or wind to generate power to charge batteries you can keep the battery bank discharge at a minimum. The point is if you install a charging system that is sufficient to handle the most common loads you can indeed keep your batteries near fully charged while you are not connected to shore power.I know this works as we have done this on our boat. We have installed solar panels that are sized to handle all the common loads we have while sailing and the alternator typically tops off the battery bank at the end of the day when we motor into an anchorage or marina. When anchored out overnight the batteries are typically discharged down to around 80%. In the morning when the sun comes up the solar panels charge the batteries back up to nearly a full charge during the day. With this system, we can stay on the hook for days without excessively discharging the batteries.My thought is that when you think about installing a battery system that will suit your needs you also need to install a charging system that will not only charge the batteries but will also cover all of the typical loads that you have on the boat while disconnected from shore power. Doing that will keep your batteries closer to fully charged and I think that will make them last longer. The bottom line is, just because battery manufacturers say you can discharge your AGM batteries down to 50% does not mean that is a good idea. Of course like I said I am not an expert and there is no such thing as a perfect system, but I think that installing a battery bank without a charging system that minimizes the load on the batteries is a bad idea.The bottom line is, just because battery manufacturers say you can discharge your AGM batteries down to 50% does not mean that is a good idea. Of course like I said I am not an expert and there is no such thing as a perfect system, but I think that installing a battery bank without a charging system that minimizes the load on the batteries is a bad idea.The bottom line is, just because battery manufacturers say you can discharge your AGM batteries down to 50% does not mean that is a good idea. Of course like I said I am not an expert and there is no such thing as a perfect system, but I think that installing a battery bank without a charging system that minimizes the load on the batteries is a bad idea.

All lead acid batteries undergo sulfation. The two major players in lead acid batteries are lead, and sulfuric acid. When a battery is fully charged, the lead is in the form of metallic lead and as the battery discharges the lead become ionized, or goes into solution. Charging a lead acid battery deposits the ionized lead back to metallic lead and the process starts again. But don't forget the sulfur in the lead acid electrolyte. There is a competing reaction where the lead forms a compound with the sulfur. Luckily, this reaction has much slower kinetics than the first so it takes time tie up enough lead to impact the performance of the battery. Equalization is the part of this process that breaks down this compound back into metallic lead and the free sulfur ions. Enough chemistry...

The LiFePO4 batteries undergo a different degradation process. Now, I don't fully understand all of these yet, I've been looking into it but I'm not yet at the same level of understanding as I i am with lead acid chemistry (you are probably saying thank goodness). As I understand it here, these batteries degrade more due to cycle count, not so much how far into the cycle they are taken (within their working range). So here you might as well use the power they have.

With your lead acid batteries you are correct, if you only take your lead acids down to say the 80% you mention (I think you can nicely go to 75% and occasionally 65% if you know you can equalize shortly afterwards) then you have measurably less sulfation happening and your lead acid batteries will last longer. But here you are on the balance of money invested in batteries, cost to charge then (both the system costs, maintenance costs, and the fuel costs – you'll never equalize using solar).

As the saying goes, ya pays your nickels and ya takes your choices...

dj

 

[jviss]

Lead acid batteries do not last indefinately under any circumstances of usage.

Yes, I was being hyperbolic. They will last a much longer time plugged in that a battery that's being cycled deeply, and subject to some abuse.

 

[jviss]

if you install charging systems like solar and/or wind to generate power to charge batteries you can keep the battery bank discharge at a minimum.

For a given load.

The point is if you install a charging system that is sufficient to handle the most common loads you can indeed keep your batteries near fully charged while you are not connected to shore power.

No you can't, unless you are running the charging system(s) constantly, or not using much juice.

When anchored out overnight the batteries are typically discharged down to around 80%. In the morning when the sun comes up the solar panels charge the batteries back up to nearly a full charge during the day.

Yes, if you're only using a trickle of power.

All of this is useless without knowing the power budget, bank size, and generation capability.