Why not LiFePO4?

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  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: Why not LiFePO4?

    BTW: The efficiency of lead acid batteries varies all over the place with time and temperature. A little bit of sulphate on the plates reduces the efficiency dramatically. The older they get the less efficient they are. Eventually one cell will lead the race of sulfation and reach 0% efficiency and fry all other cells.

    As far as I can tell the efficiency of LifePO4 is pretty constant and very close to 99% at lower charge currents. Probably down to 95% at 1C charge rate.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?
    feedhorn wrote: »
    BTW: The efficiency of lead acid batteries varies all over the place with time and temperature. A little bit of sulphate on the plates reduces the efficiency dramatically. The older they get the less efficient they are. Eventually one cell will lead the race of sulfation and reach 0% efficiency and fry all other cells.

    This is not really true. Quite a number of people get long service out of lead-acid with consistent cell performance. Small amounts of sulphation are normal over lifetime and do not dramatically effect performance. Nor is it normal for a single cell to fail causing over-Voltage in the others (it would have to short, and this does happen).

    Just as you can't judge all lithium batteries based on tales of a few you should not judge lead-acid based on limited experiences.
  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: Why not LiFePO4?
    Quite a number of people get long service out of lead-acid with consistent cell performance.

    I've found this to be true if you keep the batteries at or above 95% SOC for the life of the battery as in a battery backup situation.

    Now if you are deep cycling even a little bit things go from bad to worse.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?
    feedhorn wrote: »
    I've found this to be true if you keep the batteries at or above 95% SOC for the life of the battery as in a battery backup situation.

    Now if you are deep cycling even a little bit things go from bad to worse.

    No. You either have very little experience with RE systems or else have experience only with systems that are not in proper working order.

    Deep cycle batteries will fare worse if not cycled.
    My own set get dragged down to 70% SOC daily for half the year and are now 5 years old. They come up to full 1.265 SG and show no signs of diminished capacity. Yes, I practice what I preach and it works. Moreover it works for everyone who follows my advice as well.
  • Ks SolarKs Solar Solar Expert Posts: 47 ✭✭
    Re: Why not LiFePO4?

    Photowhit made a comment hit with me . It has to do with intended use. Chemistry compared if you just float it for emerg. only. That once a year when power goes out and you want to keep the fridge running for a day or two.

    On my lipo I use for ebike I float it at 3.8 instead of max of 4.2 v per cell for storage.

    Lead acid wants to be topped off all the time for storage.

    I love my lithium for power density and no acid to leak/maintain. And it stores well.

    Which would last longer in "storage" mode?
  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: Why not LiFePO4?
    My own set get dragged down to 70% SOC daily for half the year and are now 5 years old.

    So you have them half the year just floating at 100% charge?

    I agree, lead acid batteries work very well if you don't use them too much.

    Automotive is a good application for lead acid. 3 seconds of discharge followed by immediate recharge. They can last for years just doing this.
  • sub3marathonmansub3marathonman Solar Expert Posts: 300 ✭✭✭
    Re: Why not LiFePO4?
    Actually lead-acid batteries are more than 60% efficient. More like 80%. And you'll find the forklift batteries can do better than 1500 cycles. More like 7000.

    I thought I might have been mistaken about the charging efficiencies.

    But I am still skeptical about the claim of 7000 cycles to 80% DOD.

    (NOTE: Need to remove any and all new references to that particular person as per instructions. Sorry.)

    For the Rolls 2 OS 33P, 2V, 1883 ah, a Series 5000 top of the line battery, the cycle life data sheet lists just over 2000 cycles to 80% DOD. Now, you could get close to 7000 cycles, but that would be at 10% DOD. Arizona Wind and Sun doesn't sell this exact battery, but I found it for just over $800 at another place. And a 12V would be 6 cells at $4800.

    For the CALB 100ah CA series cell, I could only find a link at EVTV, which is run by Jack Richards, who is a bit controversial. This is from 6/26/2012 too. http://evtv.me/2012/06/battery-jump-shift/ The claim is that it is 3300 cycles to 80% DOD, although this is just a claim from him based on a comparison to the older SE series cell cycle life at 100% DOD. I think it is possible to get a large ah CALB battery at $1/ah, so theoretically the 1883ah li-ion battery would cost $1883. And a 12V would be 4 cell at $7532.

    So the CALB would cost about 57% more, but would give 65% more cycles to 80% DOD. So it would seem that both end up being about the same price per cycle to 80% DOD.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?
    feedhorn wrote: »
    So you have them half the year just floating at 100% charge?

    I agree, lead acid batteries work very well if you don't use them too much.

    Automotive is a good application for lead acid. 3 seconds of discharge followed by immediate recharge. They can last for years just doing this.

    You appear to have an anti-lead-acid battery agenda which is not at all justified. The majority of off-grid systems run these batteries cycling to as much as 50% SOC daily, year-round for years on end with no problems.

    Your opinions on lead-acid are not born out by facts.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?

    If a forklift battery can last 20 years in an RE application as some claim then the cycle life is simply 365 * 20 = 7300. Whereas I wouldn't guarantee that myself, it certainly indicates a life much longer than 1500 cycles which is what is associated with the smaller batteries like GC2's.

    Even if you adjust the FL battery to a "daily work schedule" of 260 days per year over 20 years that's 5200 cycles. If you cut it down to 10 years it's still more than 1500 by nearly double.
  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: Why not LiFePO4?
    You appear to have an anti-lead-acid battery agenda which is not at all justified.

    You should study all the efforts that were made to make solar powered street lights work using lead acid batteries. Turns out its almost impossible to make them work for more than just a few months.
  • BB.BB. Super Moderators, Administrators Posts: 32,006 admin
    Re: Why not LiFePO4?

    Lead acid battery for "simple"street lights is not the same.

    But to have an automatic off grid power system is a nightmare. In that application, a battery that can avoid state of charge issues would be worth the extra money.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • PhotowhitPhotowhit Solar Expert Posts: 5,650 ✭✭✭✭✭
    Re: Why not LiFePO4?

    As with your lithium metal based batteries chemistries, Lead acid based batteries come in different mixes, Car batteries are Lead Calcium and can hold a charge for a very long time, and can deliver a big punch to start vehicles, These are different from Lead Antimony batteries which have higher cycling, higher self discharge.

    I'll use Crown forklift/traction batteries as an example, since NAWS sells them. They are actually designed to be deeply discharged, the warranty on them is;

    1500 cycles to 80% DOD for five years full replacement.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: Why not LiFePO4?

    You Should Know:

    Even those little stick in the ground LED Solar yard lights are now using LiFePO4. At least for the Good Ones.

    Wonder Why?
  • BB.BB. Super Moderators, Administrators Posts: 32,006 admin
    Re: Why not LiFePO4?

    Because NiCad batteries are almost illegal in many countries due to anti-pollution laws?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: Why not LiFePO4?

    You Should Know:

    Almost all the newest portable power tools are now using LiFePO4.

    Wonder Why?
  • PhotowhitPhotowhit Solar Expert Posts: 5,650 ✭✭✭✭✭
    Re: Why not LiFePO4?

    See above...

    I thought power tools used Lithium Magnesium of some sort?

    PS- way off topic since your now comparing high density power sources. Little to do with Off Grid, though I guess we could invite the Nickel Iron/Edison faction in and have polar opposites on the weigh scale argue... Try one of them in your RV!
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: Why not LiFePO4?
    Photowhit wrote: »
    See above...

    I thought power tools used Lithium Magnesium of some sort?

    PS- way off topic since your now comparing high density power sources. Little to do with Off Grid, though I guess we could invite the Nickel Iron/Edison faction in and have polar opposites on the weigh scale argue... Try one of them in your RV!

    Not anymore they are all going to LiFePO4.

    I would take a huge array of Edison Iron to come up with the 1000 amps that my LiFePO4 will produce.
  • PhotowhitPhotowhit Solar Expert Posts: 5,650 ✭✭✭✭✭
    Re: Why not LiFePO4?

    If you have a 1000ah battery you need to change your info.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • BB.BB. Super Moderators, Administrators Posts: 32,006 admin
    Re: Why not LiFePO4?

    I hope that my "newish" power drill/driver kit LiABC type batteries will last more than a couple of years. There are enough people that have complained that it is not a given.

    But--There is a big difference between a 100 AH Li battery back and and a 1,000 AH Lead Acid Battery bank in stored energy. If you need light weight, high current (charging/discharging), and ability be at other than >75% state of charge during long term storage--LiFePO4 and other chemistries are not bad.

    However, if your surge current requirements is not large, but you need a fair amount of AH/WH storage--LiABC is not cheap.

    But I do agree that reading about LiFePO4 batteries is very interesting and, for some applications, may be a good solution. But it is still not yet cheap and can be damaged by improper operation/equipment problems--Just like pretty much any other rechargeable battery chemistry.

    Even the 100+ year old lead acid storage battery has various "flavors" and, apparently, even a battery manufacturer with a long/illustrious history can lose the recipe for lead acid on occasion.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?

    You should know:

    Citing non-comparable applications doesn't prove anything.
    At least not about the differences in batteries.
  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: Why not LiFePO4?

    Batteries are Batteries Big or Small:

    Nissan Leaf car uses LiFePO4 batteries. They had some problems in hot country like Phoenix ,AZ but now they have fixed that.

    Does anyone know what they fixed?
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Why not LiFePO4?
    feedhorn wrote: »
    Batteries are Batteries Big or Small:
    Well, when they get down to > $2.00 a amp hr @ 12 v , they sound like something people would be interested in. Right now Sams club GC-2's are $84 x 2 = $168 @ 12 v = $.76 per amp hour. Until then it's all hype. At almost $7.00 a amp hour you dreaming.
  • VicVic Solar Expert Posts: 3,112 ✭✭✭✭
    Re: Why not LiFePO4?

    Am glad that some are using Li batteries in RE applications. Great to hear that many, who use them, are happy.

    Would guess that for RVs they are often a good fit.

    Every day that I get up, and my 9 year-old FLA banks are still functioning fine, brings a smile. Amazing to me that FLA batteries work so well ... nary a problem with those here ... knock on wood.

    Amazing, also, is that this technology dates back about 150 years, and there has been so little change in the basic chemistry of Flooded batteries -- they really do and have worked quite well for a very long time -- little need for much change.

    Any battery can be damaged in shipping or by the user (or Dealer) or by defective equipment, or perhaps from manufacturing defects. But, in general it seems that 95-ish percent of the RE users of FLA batteries seem happy, often, very happy with their FLA batteries.

    FWIW. Happy camper, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?
    feedhorn wrote: »
    Batteries are Batteries Big or Small:

    That is the least correct statement you have made to date.
  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: Why not LiFePO4?
    Well, when they get down to > $2.00 a amp hr @ 12 v , they sound like something people would be interested in. Right now Sams club GC-2's are $84 x 2 = $168 @ 12 v = $.76 per amp hour. Until then it's all hype. At almost $7.00 a amp hour you dreaming.

    You can only use about 25% of a GC-2's amp hour rating because the sun doesn't shine long enough to refill more than that amount so you should say they are more like $3/ah.

    Since LiFePO4 batteries last up to 5 time longer than GC-2's now they look more like $15/ah.

    I expect to make a $2000 profit by using LiFePO4 over its lifetime.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Why not LiFePO4?
    feedhorn wrote: »
    You can only use about 25% of a GC-2's amp hour rating because the sun doesn't shine long enough to refill more than that amount so you should say they are more like $3/ah.

    Since LiFePO4 batteries last up to 5 time longer than GC-2's now they look more like $15/ah.

    I expect to make a $2000 profit by using LiFePO4 over its lifetime.
    Yada, Yada, Yada, you just keep on adding some other justifications to make your's look better than what they are, ain't happening guy. The funny thing is you won't be back when yours fail. My customers get about 5 years out of a set of GC-2's , don't know one who isn't happy with what they have.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?
    feedhorn wrote: »
    You can only use about 25% of a GC-2's amp hour rating because the sun doesn't shine long enough to refill more than that amount so you should say they are more like $3/ah.

    Again not true. It depends on where you are and how much panel you've got. I use more than 25% way up here in Canada.
    Since LiFePO4 batteries last up to 5 time longer than GC-2's now they look more like $15/ah.

    Can you cite any examples of LiFePo lasting 40 years? Because that's the benchmark they're up against: 8 years from good quality GC2's looked after.
    I expect to make a $2000 profit by using LiFePO4 over its lifetime.

    I seriously doubt you'll be able to prove that statement.

    I am not against LiFePo batteries at all, and believe they will play an important role in RE in the future. Probably not-too-distant future at that. But your unjust slagging of lead-acid is based on nonsense so it makes your pro-LiFePo stance look absurd.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Why not LiFePO4?
    feedhorn wrote: »
    .. Nissan Leaf car uses LiFePO4 batteries. They had some problems in hot country like Phoenix ,AZ but now they have fixed that.

    If you want to see the details on what they are made of, and other issues like thermal management, grab a beverage:

    https://www.youtube.com/watch?v=9qi03QawZEk

    Professor Jeffrey Dahn at Dalhousie.

    I'm just sad that nearly ALL discussion of Lifepo4 devolves beyond the technical / operational uses, and ends up in the usual political / marketing / emotional arena, much of it coming from those with no first-hand knowledge other than rc modeling or dramatic newsbytes which are often found wrong when the details are examined.

    Maybe our own example (myself included) is one reason major lead-acid manufacturers haven't included lifepo4 as an *additional* offering - too much disinformation from BOTH sides to make them profitable.
  • PhotowhitPhotowhit Solar Expert Posts: 5,650 ✭✭✭✭✭
    Re: Why not LiFePO4?

    I think feedhorn is basing the GC2 battery life on his bad experience getting only 2 years out of a set. I think you had outstanding service from your set, I abused a set of cheap Sam's club GC batteries, regularly taking them down to 50% DOD during the summer and got 5 years out of them. If you all are going to square off on GC batteries, let me suggest that as a typical age, though they obviously can go longer.

    I do agree as 'Coot has that they may be a very real future. I also am glad people are pioneering their usage. It might well be a recommended battery now, in applications like Rv's and hand tools where weight and/or more toxic options are currently used. I'll add a nod to their more efficient charging here so no one feels snubbed.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: Why not LiFePO4?

    Granted, I only know my personal situation really well...

    I've been through 5 sets of 4 GC-2's in the last 12 years and trying to baby the b*tards all those years was a misery.

    What a Joy it is to finally get beyond all that mess.
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