Why not LiFePO4?

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Comments

  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Why not LiFePO4?
    zoneblue wrote: »
    I got the impression that if you have to parallel them, you do it at the cell level. I suspect the reason for this is that it minimises the cell count for monitoring/balance purposes if you go that route. Lots of fuses though.

    Parallel for capacity first in groups, and then series connect those groups to get your voltage - still a single "string" if you will. For example, if you had thirty-two 90Ah cells for a 24v battery, you'd end up paralelling 4 cells to make a group. Then that would be 8 "groups of paralelled cells" wired in series to raise voltage 24v. In this case, this would make a 360ah, 24v battery. Breaking up a lifepo4 bank into parallel individual strings attached only at the end terminals is asking for trouble.
    Availability is the thing in my mind, once they are easier to get theyll take off.
    You'll never see them at a regular battery dealer. Since they primarily made for amateur EV, (that is the reason we CAN get them), where super-high rate with cylindrical cells is not needed, and distributed by those companies, that is where you look. There are some specialty battery houses like batteryspace and Elitepowersolutions that will also get them to you. GWL also comes to mind.

    The average guy doesn't even know they exist. Many rc modelers, and it seems even amateur radio operators don't know either, shelling out bucks for complicated cylindrical high-rate battery setups thinking that's all there is.

    If you want 'em, you've got to know - and now anybody lurking does.

    Re: the heat. Yes, any battery likes room temperatures the best. High heat aggravates parasitic reactions. Combine that with unnecessarily high charging voltages in some cases, and you've got double-trouble. :)
  • karrakkarrak Solar Expert Posts: 326 ✭✭✭✭
    Re: Why not LiFePO4?
    Skyko wrote: »
    Will you get 3000 to 5000 cycles out of LiFePO4 in the warm temperatures of Australia?

    I have read somewhere that they age faster in higher temperature environments (but so does lead acid).

    You are right about temperature, fortunately we only get a few hot months in summer, our climate is similar to southern coastal California. If I lived in a hot inland area I would look at housing the batteries underground to keep them cool.

    I would be surprised if our battery bank gets above 30 degrees C (86 degrees Fahrenheit). This prompts me to add temperature to my battery logging.
    Off-Grid with LFP (LiFePO4) battery, battery Installed April 2013
    32x90Ah Winston cells 2p16s (48V), MPP Solar PIP5048MS 5kW Inverter/80A MPPT controller/60A charger, 1900W of Solar Panels
    modified BMS based on TI bq769x0 cell monitors.
    Homemade overall system monitoring and power management  https://github.com/simat/BatteryMonitor
     

  • karrakkarrak Solar Expert Posts: 326 ✭✭✭✭
    Re: Why not LiFePO4?
    zoneblue wrote: »
    I got the impression that if you have to parallel them, you do it at the cell level. I suspect the reason for this is that it minimises the cell count for monitoring/balance purposes if you go that route. Lots of fuses though.

    PNjunction has pretty well answered this. If my memory can be trusted I do remember reading that the batteries have been tested and are unlikely to catch fire if they get an internal fault. The single fuse to the solar controller, the circuit breaker in the inverter, making sure that the electrical connections to the battery terminals are all low resistance, putting a cover over the batteries and being very careful when working with metal tools near the batteries I think are sufficient precautions.
    Off-Grid with LFP (LiFePO4) battery, battery Installed April 2013
    32x90Ah Winston cells 2p16s (48V), MPP Solar PIP5048MS 5kW Inverter/80A MPPT controller/60A charger, 1900W of Solar Panels
    modified BMS based on TI bq769x0 cell monitors.
    Homemade overall system monitoring and power management  https://github.com/simat/BatteryMonitor
     

  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Why not LiFePO4?
    zoneblue wrote: »

    Sounds like a neat motorhome upgrade project. Will look out for a small set to pair with the upcoming brat controller, whatever i can get under the 400 dollar customs threshold.

    zoneblue wrote: »
    Our motorhome is 100% 24v, both house and SLI. Wasnt hard.
    $400 ought to get you a 40 amp hr battery @ 24V, sounds like a good project. Make sure you get the ones with >5,000 cycles and $.14 a kw.
  • creekycreeky Banned Posts: 31
    Re: Why not LiFePO4?

    Hi everyone. This is my first post.
    I recently ran across a US manufacturer of LFP (LifePO4 is just to long) batteries. I don't want to sound like a spammer on my first post, so I'll just say they have a 9kw battery with built in battery management and fuse. So hook it up and go. at 12v it's around 3400. You can find them by googling lifePO4 and balqon. Hope this is okay.
    I have a perfectly fine 4 year old set of lead acid (6) crown 395s (at 12v) which I am absolutely tired of maintaining. Plus, with my cold climate, winter is a pita.
    I dream of buying an LFP bank. Imagine, fewer worries about temp. No maintenance for, with my power usage, 20 years. 1/3 more power (cause I can go from my 2kw per day 20% dod to 3 kw at 33% and still have my battery pack last 20 years). Plus all the other benefits already mentioned.
    I'm with you feedhorn. there is no way I'd be looking at any kind of lead acid battery bank. Not anymore.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?

    Welcome to the forum creeky.

    $3,400 for a 9kW (750 Amp hour) 12 Volt battery? That is hideously expensive! There is no way that could have enough advantage over lead-acid to make it worthwhile.

    I find, repeatedly, that people who are dissatisfied with the ol' FLA's have their systems set up wrong and ruin the batteries. There is no inherent fault in the batteries themselves.

    Why do you think the LiFePo will be better in Winter? Just because they won't freeze? Neither will the lead-acid if you keep the charge state up. And if you don't/can't then you have an energy input deficit anyway and nothing will save you.

    As for these claims of cycle life and years lasting for the lithium-based units, this has yet to be proven in the real world RE applications. I just hope people aren't shelling out tons of money for a promise that doesn't come true. So far the only proven advantage is the variable SOC tolerance. Where there is no need for that (most systems) there's no need for the added expense.

    Hopefully the pioneers will get the price down and more people will use them, broadening the database of real experience (instead of lab tests and extrapolations from other applications). Then lead may find itself with a true competitor. So far this is not the case.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?

    In case anyone was wondering, let's just look at what we know about creeky's system:
    creeky wrote: »
    I have a perfectly fine 4 year old set of lead acid (6) crown 395s (at 12v) which I am absolutely tired of maintaining.

    First note he says they are "perfectly fine". That's good, and is to be expected at only 4 years.

    Now, there appear to be six 395 Amp hour batteries in a 12 Volt system. Right away they opens up problems. Three parallel strings and 1185 Amp hours. If that much power is actually needed, it should not be a 12 Volt system. Parallel strings and multiple charge controllers to get enough current. All problem-makers.

    In terms of recharging it should have at least 118 Amps of current - which is two 60 Amp controllers pushed to the limit. It would also require at least 1839 Watts of array to provide that current, and preferably more. These are 'tall case' batteries and really need high current for quick and proper charging with stratification.

    How close this comes to what he's actually got I don't know. Were it me needing 14 kW hours of stored power I would have gone with a 48 Volt system to begin with. Much less likely to misbehave.
  • PhotowhitPhotowhit Solar Expert Posts: 5,650 ✭✭✭✭✭
    Re: Why not LiFePO4?

    With him expecting a 20 year life, I figured he had 6 - 2 volt cells? But it doesn't appear Crown makes 2 volt batteries that small. I would also question getting a 20 year service life from L-16 6 volt cells in the best of situations.
    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.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?
    Photowhit wrote: »
    With him expecting a 20 year life, I figured he had 6 - 2 volt cells? But it doesn't appear Crown makes 2 volt batteries that small. I would also question getting a 20 year service life from L-16 6 volt cells in the best of situations.

    Yes I didn't see a 2V that small listed either and I shouldn't think managing six cells is all that hard, so I extrapolated based on their 395 Amp hour 6 Volt. Thus we have a big difference in possibilities.

    Nor would I expect them to last 20 years. There are no guarantees on lifespan, only estimates and claims.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Why not LiFePO4?

    Yep, Balqon is another alternative, from way back when everyone started with Thundersky. Interestingly enough, they are one of the EV makers that don't use small super high-rate cylindrical cells apparently because the utility trucks have space to fit the large prismatics.

    I can't comment on them since I have had no personal dealings. I'd do a quick search and keep an open mind.

    Yep, upfront costs are high. We've kind of been through this before, but I will say that I'd rather have Cariboocoot maintaining my FLA bank, than just dropping a wad of cash on lifepo4 without knowing what's going on. I still prefer the "hands on" approach of putting together a simple 12v / 40ah 4S bank of balqon's (or gbs, winston, calb, etc), before opening the wallet wider. Then YOU, not the salesman can decide if lifepo4 is right for you or not.

    Instead of buying into the sales hype, put together a "learner bank" before you splurge on something larger. We tend to recommend doing this with lead, and the same advice is applicable here. Also, like someone who maintains an FLA bank with a hydrometer, a wise lifepo4 user will also measure voltages to make sanity checks along the way. Or, you can just slap stuff in, cross your fingers that balancers / chargers are always perfect and ignore it at your lei$ure.
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Why not LiFePO4?

    I still prefer the "hands on" approach of putting together a simple 12v / 40ah 4S bank

    PNj I concur wholeheartedly, however I am at a loss to find an application for that small an Ahr battery.
    For example, our guest cabin has a 2 x 100Ah (well aged) Ni-Cd's and I am not sure I could trust guests (relatives) to manage DoD from that small (40Ah) a bank properly...

    I also thought about powering the satellite internet but it would use about 22W over 12 hrs (260Whr) so a 40Ah batt. @ 12 v (480Wh) would make it through the nite (~45% SoC) and have less than a days reserve.
    Without 2 + hrs of good sun (Fall is coming) it is marginal by my estimates. I am thinking a 100 ahr battery would be needed.

    Thoughts.
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Why not LiFePO4?
    westbranch wrote: »
    PNj I concur wholeheartedly, however I am at a loss to find an application for that small an Ahr battery.

    Here the major application would be one of discovery, and to treat it just like you would your own bank if it were much larger. Ie, scale your operations to what, 0.1C to maybe 0.2C charge rate simulating a typical solar array? The same goes for discharge - about 0.05, 0.1C whatever it is close to what you are doing now, or plan in the future. The simplest would be to just burn a CFL on an inverter and watch it go to 80% DOD easily. Mind blown #1.

    But, now use an inverter with a load that has a huge startup. It would handle 40A no problem continuous, and 120A surge for 30 seconds or so without harm. These are extremes of course when you scale things, but still it shows the huge headroom you have for inductive or other heavy startups. Note that yes, there is a bit of voltage sag at the *extremes*, which we won't normally encounter - so for the most part Mr. Peukert has taken a stage-right. Your inverter, if large enough of course, might not really notice it at all even if you hit that up down at 75% DOD. Mind blower #2.

    Simulate poor solar insolation by leaving your bank less than fully discharged for a day. Or 6 months. No float. Come back to no damage or loss of capacity, aside from the minor self-discharge, whatsoever IF your bms system isn't acting like a parasitic load! I don't use one. Use a smaller array and NEVER get a full charge and see if you can live with that. Play with what an acceptable PSOC environment would be like. Mind blown #3.

    Measure the temperature, perhaps even sound, of gear using the lifepo4. See if it runs cooler, runs a shorter use-cycle, and is quieter due to being in a higher overall voltage compared to lead during the discharge cycle.

    Charge it to full with your generator and watch it efficiently use the generator up to about 95% SOC before the relatively miniscule absorb happens. Saving fuel now too.
    For example, our guest cabin has a 2 x 100Ah (well aged) Ni-Cd's and I am not sure I could trust guests (relatives) to manage DoD from that small (40Ah) a bank properly...

    I manage the LVD on my own 40ah GBS battery with a simple Powerwerx ITS-12 switch. It is primarily designed for lead, but fortunately has a nifty settable timeout when 12.8v is reached! I set the timeout for the minimum of 2 minutes, which at my 0.05C leaves me plenty left safely after the shutoff. It is rated for 35A continuous current through the relay, and I never get that high anyway. There is also a hard-lvd of about 11.4v, which is really too low for me (if you reach that before the timer gets to it), but better than taking the cells down to zero. With the timer and a load typical of what we would run, I see no problem. Simple wiring and no funky programming - just a rotary switch for the timer. Note that it uses 150ma in normal use, so that would have to be accounted for. I haven't measured it when it cuts off.

    From a discovery standpoint, the application can be just simple CFL's running off an inverter, hit it with a motorized saw temporarily, or whatever you have. It doesn't have to be exactly practical immediately, but gives valuable insight on what you could design later on. That's the importance of hands-on, something you don't get when the ONLY thing considered is price alone. When you get one and play with it for a littlle while, you can see how many variables can be thrown into the mix to suit YOUR style of operations, and it can vary.

    Getting off track here .... but when considering price, note that I am only using 4 cells and an external LVD of my own choosing, and not the BMS systems that they tend to tack onto those pre-built kits. Luckily, it isn't 2008 anymore, so I didn't have to deal directly with overseas, and got local stock pretty quick. As always, make sure you get the inter-cell links, end terminals if needed, and the banding to keep them tightly together. I found the 3.7v / 6A single-cell charger from Batteryspace quite convenient just to be able to manually charge for initial balance if needed.
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Why not LiFePO4?

    I'll have to sleep on it, too much right now, getting late, wine for dinner and bottling another carbouy too...
    .
    I understand the scaling of an application but wanted to stress test with real life 'hazards', ie cold temps, low insolation, short hours near Dec 21..... and hope for clear skies 8).

    Once we get past the 'CODE' items at the new build I might try testing in the dead of winter with a cold battery and one 140W panel and a Kid on a 12 v setup with an overnight run of the 'Net' dish...
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: Why not LiFePO4?

    It sure is amazing what you can tell about a system from that half line spec, eh ;)
    Now, there appear to be six 395 Amp hour batteries in a 12 Volt system. Right away they opens up problems. Three parallel strings and 1185 Amp hours. If that much power is actually needed, it should not be a 12 Volt system. Parallel strings and multiple charge controllers to get enough current. All problem-makers.

    In terms of recharging it should have at least 118 Amps of current - which is two 60 Amp controllers pushed to the limit. It would also require at least 1839 Watts of array to provide that current, and preferably more. These are 'tall case' batteries and really need high current for quick and proper charging with stratification.

    How close this comes to what he's actually got I don't know. Were it me needing 14 kW hours of stored power I would have gone with a 48 Volt system to begin with. Much less likely to misbehave.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • PhotowhitPhotowhit Solar Expert Posts: 5,650 ✭✭✭✭✭
    Re: Why not LiFePO4?
    PNjunction wrote: »
    But, now use an inverter with a load that has a huge startup. It would handle 40A no problem continuous, and 120A surge for 30 seconds or so without harm. These are extremes of course when you scale things, but still it shows the huge headroom you have for inductive or other heavy startups. Note that yes, there is a bit of voltage sag at the *extremes*, which we won't normally encounter - so for the most part Mr. Peukert has taken a stage-right. Your inverter, if large enough of course, might not really notice it at all even if you hit that up down at 75% DOD.

    We recently had a fellow doing a day time off grid solar, to supply his day time loads, I can see this as a nice solution for voltage sags in starting his large A/C compressors, while maintaining a minimal battery bank. He was essentially running his home off grid during the day (not selling to the grid) and running on grid over night, believing he was saving money... I think we were all skeptical, but a tiny bank with large available power for load starting might make the numbers work out better for him...

    It's too late at night.... I'll kick start the brain in the morning and try it out...
    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.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Why not LiFePO4?

    This sounds like a good bet for him.

    I'd like to point out for lurkers (with over 3K views of the topic, it can't be just the 10 or so of us doing all the reading!), that while I don't share Cariboocoot's and other's viewpoint based on pricing alone, I can say I agree with him COMPLETELY about lead acid being able to do the job, IF you engineer it right, and do at least a minimal amount of maintenance, which he an others tirelessly do with extended examples and calculations.

    Lifepo4 didn't suddenly make lead stop working.

    In other words, keep it real. Don't pay for features you'll never use with lifepo4. In my case, I'll NEVER build a housebank using high-rate cylindrical cells, and stick to large prismatics with a lower rate, simply because in our application for a reasonably sized battery bank, you'll never need 10C or more of charge/discharge capability. Why pay for 10C ability if you'll never use it?

    In a like manner, it would be foolish to overspend on advanced lifepo4 features that you are not currently needing if FLA's or AGM's adequately meets your needs or style of operation.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Why not LiFePO4?
    PNjunction wrote: »

    I'd like to point out for lurkers (with over 3K views of the topic, it can't be just the 10 or so of us doing all the reading!), that while I don't share Cariboocoot's and other's viewpoint based on pricing alone, I can say I agree with him COMPLETELY about lead acid being able to do the job, IF you engineer it right, and do at least a minimal amount of maintenance, which he an others tirelessly do with extended examples and calculations.
    The flip side of the above is all the posts that are made trying to justify spending 3-4 times the cost of lead acid that may never come to pass. Some say 1,000 cycles on lifepo4 while some of the fans say >5,000. The fact none of you know and it's just a bunch of guessing until there is a proven track record on them in RE and not extrapolating data from some other use or someone with a 40 amp hr battery with very little data.
  • SkykoSkyko Solar Expert Posts: 121 ✭✭✭✭✭
    Re: Why not LiFePO4?

    The question still remains why no big boy manufacturers in the USA have taken up LiFePO4.

    They are all out for profit and lead acid has to be a pretty low margin business ($80 for a 70 pound battery, there just can't be a ton of profit in that).

    Why are these large LiFePO4 cells not available at Sears, West Marine, Cabelas ?
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Why not LiFePO4?

    West Marine has the Master Volt line, I know they make/sell them, pricey you can bet, they don't have them in the catalog I have. The do carry one LiFePO4 battery for the Torqeedo electric motors 104 amp hrs @ 24V= $2,599
  • SkykoSkyko Solar Expert Posts: 121 ✭✭✭✭✭
    Re: Why not LiFePO4?
    West Marine has the Master Volt line, I know they make/sell them, pricey you can bet, they don't have them in the catalog I have. The do carry one LiFePO4 battery for the Torqeedo electric motors 104 amp hrs @ 24V= $2,599

    I think the Torqeedo may be Lithium Manganese
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Why not LiFePO4?
    Skyko wrote: »
    I think the Torqeedo may be Lithium Manganese
    Your correct, I never looked them up and they have a specification sheet online. Battery chemistry: Li NMC
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Why not LiFePO4?

    Looks like this may also be a LiFePO4 application, the Waka Waka Power unit...https://us.waka-waka.com/media/Compare-WWL-WWP-%28dollar%292.jpg
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • creekycreeky Banned Posts: 31
    Re: Why not LiFePO4?
    zoneblue wrote: »
    It sure is amazing what you can tell about a system from that half line spec, eh ;)

    thx for that. Needed a laugh.

    I built my system 5 years ago. when there was quite a bit of BS on the web, and, in my area, no one who had actually built one. So I made a few mistakes. I went 12v. What did I know? I bought a PWM controller based on a solar guru saying that was what I needed. Ooops. I thought I'd walk into a store and there would be a system I could take home. hahahahahaha.

    So after some muddling and fuddling. I have a 14kw or so battery bank. Ya, it's not perfect, but it works great. Two MPPT 60 controllers. Solar panels are a deal I got on 48v panels, used: One set is 1kw, the other set is .5kw soon to be 1 kw also. I had to build all my own interconnects. I had to do all the voltage drop stuff. I had to find the wire. The connectors. Do all the wiring. But at the end of the day. I have a solar system that works well. I bought a cheap inverter. Now I have one 1/2 the power that runs all the same stuff and cost twice as much. Live and learn. TBS 1600. It is sweet (and uses >10 watts on idle, compared to 35).

    Now you can laugh at me with two lines of spec. :)

    A 9kw LFP is equal to my 14kw LA. But the LFP requires no watering. When it gets cold it doesn't derate. Its ability to provide my 2kw daily power needs are not reduced. Btw. In my area I have used my LA pack right down to -17C. I sure wasn't using 2kws. The LFP weighs 1/3 the weight. It does not off gas. It will last 3 times longer (20 years at 30% DOD). My lead acid pack I suspect will last 5 years, fingers crossed. As I have done almost everything wrong that can be done wrong. The LFP charges more efficiently, I've heard like 20% more efficiently. Man that will make a big difference here in the frozen north during short days, lots of clouds time. It will deliver 500 amps at 50% dod.

    Personally, I don't understand peoples reluctance to change. Is your LA pack made of gold and you sacrificed a goat over it? It's just a battery pack. I don't see anyone rushing out to buy an Amiga when they need a new computer. Cause, gosh, those new processors aren't proven. They're too fast.

    imho. LFP (cause I'm to lazy to type out LiFePO4) is the best thing to hit solar in many a year. Now, from my perspective, we have a battery tech that can let us design systems with 20 year no part needs replacement lifespans. I don't know about you'ze. But when my battery pack dies I won't blink in tossing LA out and bringing a better solution in.

    and the balqon (who has never heard of me and I use as an example only) has BMS and a fuse built right in. It's plug and play. And when you think you'd need 3 LA packs with all the maintenance etc. in that time frame. Who needs it. I'll save my money. And time.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?

    I'll save my money too, and stick to lead-acid until someone else takes the risks and proves the lifespan claims of the LiFePo. And for newbies, a mistake can destroy any type of battery chemistry; how much money do you want to gamble?

    And yes, boys and girls, I really can figure out quite a bit from a little information. When I was a lad we had to learn "black boxing" (I suspect most of you don't even know what that is). Little did I know at the time I would spend most of the rest of my life applying the principles involved.
  • creekycreeky Banned Posts: 31
    Re: Why not LiFePO4?

    Cariboocoot. Can I ask if you live off grid and need this power to keep your fridge running? And plan to continue to do so for some time to come?
    Cause if you stick to LFA or lead acid you're spending more money to do more maintenance for a system component with a shorter lifespan and troubled capacity. As for gambling. These are risks for sure.
    My zen master (grandmother) imparted the wisdom of the open mind.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?
    creeky wrote: »
    Cariboocoot. Can I ask if you live off grid and need this power to keep your fridge running? And plan to continue to do so for some time to come?
    Cause if you stick to LFA or lead acid you're spending more money to do more maintenance for a system component with a shorter lifespan and troubled capacity. As for gambling. These are risks for sure.
    My zen master (grandmother) imparted the wisdom of the open mind.

    Yep. Five years so far on the latest set and no maintenance issues at all. One gallon of distilled water ($3) and it's not used up yet.

    I could buy three (probably five here in Canada) lead-acid sets for the price of one LiFePo, and I could be dead before the last batteries are. I'm not worried about it.

    People talk about amazing new technologies. 90% of them don't pan out. I'm not saying this is the case with lithium, but I'm not going to dive in believing the claims when there are insufficient RE installations to back those claims up with real data.

    Maybe I shouldn't have spent all that time and money learning things. Of course if I hadn't I'd be asking questions instead of providing answers. Well, at least that way someone might listen.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Why not LiFePO4?
    It will last 3 times longer (20 years at 30% DOD). My lead acid pack I suspect will last 5 years, fingers crossed. As I have done almost everything wrong that can be done wrong. The LFP charges more efficiently, I've heard like 20% more efficiently. Man that will make a big difference here in the frozen north during short days, lots of clouds time. It will deliver 500 amps at 50% dod.
    Wow, now were getting up there, 7300 cycles !!! I doubt I'll be around in 20 years.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Why not LiFePO4?
    Wow, now were getting up there, 7300 cycles !!!

    Yes, and how many actual installations that prove this claim? Have they been around 20 years to bear this out? No.

    I think what people keep missing is the fact that the LiFePo does not have a proven track record of performance yet. As such most people can not justify the higher capital cost for a claimed benefit.

    And that's where it stands today until some real world data builds up.
  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    Re: Why not LiFePO4?

    Give a round of applause for all the early adopters of new technology. We need real world testing and that is not something that a manufacturer is able to emulate in their development process.

    One of the latest possible "fails" that comes to my mind is the Nest thermostat. There is a lawsuit that claims the Nest folks have exaggerated the claims.

    I have never minded letting others be the first on the block with the new stuff. When my 5 year old FLA's give out I'll likely choose the same old technology and continue monitoring them as well as checking the news on the LifePO4's. Our present FLA's don't require all that much time to maintain even including the time to log the SG data. But that is me.




    "black boxing"... looking inside a machine, a system, to see how it works?
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    Re: Why not LiFePO4?

    I meant to add I know someone with a cargo trailer that he converted to a travel trailer... 8 x 20 ft or so. It has more PV panels than our cabin. He switched to a LifePO4 battery a short time ago. He is running a small mini split on his solar power. He camps in hot CA a lot and wanted his A/C off grid. That will be a project I'll be watching closely.
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
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