Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

karrakkarrak Solar Expert Posts: 326 ✭✭✭✭
I have put together a set of comparative specifications for nominal 12 volt LiFePO4 and Flooded Lead acid batteries to hopefully bring some clarity to the debate about the two battery technologies.
I am not saying that the batteries should be operated at the loads specified, they are there for comparison.
The Lifespan and costings are of course only indicative and are dependent on many variables and how the batteries are used/abused.
I have no experience of using FLA batteries in off-grid systems, the data on FLA batteries are what I have gleaned from many sources.






LiFePO4
Flooded Lead Acid







Total Operating Voltage Range
14.4 – 11.2
15.5 – 10.5


Normal Operating Voltage Range, No Load
13.8 – 12.8 (90%-20%SOC)

15.5 – 12.0 (100%-50%SOC)



Normal Operating Voltage Range, C/8 Load
13.8 – 12.4
15.5 – 11.0


Normal Operating Voltage Range, C/2 Load
13.8 – 12.0
15.5 - 10.5


Max sustained charge rate
1C
C/8


Recommended sustained charge rate
N/A
C/10


Sustained discharge rate
1C
C/8


Peukert Coefficient
~1.02
1.2-1.6


Current efficiency
>95%
<90%


Lifespan

~10 years

~6 years


Warranty
5 year prorata (balqon)
5 year prorata (trojan)


Cost per kWh
~US$340
~US$130


Cost per usable kWh ($/kWh/cycledepth)
~US$523
~US$325


Cost per usable kWh per year
~US$52.30
~US$54.20




Trojan T105-RE from NAWS assuming [email protected]% charge/discharge
http://www.trojanbatteryre.com/PDF/datasheets/T105RE_TrojanRE_Data_Sheets.pdf

Winston LYP cells from Balqon assuming 3650 cycles @65% charge/discharge
http://www.balqon.com/wp-content/uploads/2013/07/35_35balqon_battery_2013.pdf
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
 

«13

Comments

  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    Fair enough comparison and inline with reality good job karrak. There is also the issue of a BMS ( $200 - ??? ) that could be optional, but any meaningful size bank is going to be $3- $10,000 + cost and with that kind of investment it's hard to take a chance without one. A disconnect contactor / solenoid alone is $150 + for 500 amps.

    Most $ $300 - $500 + charge controllers should have enough variables in the settings to charge them, some older Inverter / Chargers may not have the kind of settings necessary for them.

    They also need compression boxes for the cells to be placed together into a battery. It is hard to know the cost, depends on the system and size.

    Don't be shocked at the freight shipping cost on them. Balqon is about 20% of the cost of the cells + ( without lift gate service ) since they require a special Hazmat designation and crated.

    As they say, It's not just a battery, Its a system. Most would want a automated system and it all costs money.
  • PhotowhitPhotowhit Solar Expert Posts: 5,655 ✭✭✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    This would be an okay assessment if off grid solar used the complete capacity every day, unfortunately for the assessment, off grid requires a lot of reserve and it is minimally used.

    If it proves out that in a LiFePo's life is they will deliver the Kwhs over time then your assessment would not be bad. ...but if you typically need 4Kwhs a day but need 20 kwhs reserve and they both last the same time frame in the assessment, LiFePo become much more expensive.

    I guess what I'm saying is you've done an assessment of the cost of available Kwh's not on typical use. Your assessment favors systems that have a regular discharge and charge cycles, off grid solar doesn't. It might if you include the cost of a generator and fuel... that doesn't work for me.
    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.
  • creekycreeky Banned Posts: 31
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    Nice post Karrak. Really nice to see the specs laid out side by side.

    According to the Balqon website, their price includes shipping, as well as the BMS, the disconnector for over/under voltage, the racking etc. BlackCherry04 you might want to go to the site and have a look at the specs and package.

    On that note tho, perhaps the FLA pricing should be a bit higher as shipping, connection cables, fuse, bus bars etc. are not included.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    creeky wrote: »
    Nice post Karrak. Really nice to see the specs laid out side by side.

    According to the Balqon website, their price includes shipping, as well as the BMS, the disconnector for over/under voltage, the racking etc. BlackCherry04 you might want to go to the site and have a look at the specs and package.

    On that note tho, perhaps the FLA pricing should be a bit higher as shipping, connection cables, fuse, bus bars etc. are not included.
    Thats only if you buy a pre packaged drop in battery bank. If it suits you, buy one, your still paying for it. Everything comes at a price.

    I must have missed the Free Shipping or they just forgot to tell me.

    http://www.balqon.com/store-2/#!/Lithium-Battery-Storage-9-kwhr-1-week-Lead-Time/p/34783145/category=2860254
  • creekycreeky Banned Posts: 31
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    I'm sorry Photowhit, but I don't understand what you are saying.

    In my case, I typically use 2.5 to 3 kw/day. Why would I need a 5x reserve?

    My solar system off grid uses a regular discharge/charge cycle. I use my power every day. I recharge every day. The advantage of LFP batteries here would be the 20% or so increase in charge efficiency. Reducing the times I need to use my generator (note. due to the size of my solar array I only use the genny in the late fall/early winter when heavy cloud in my area reduces solar production ... ie: two days ago my 1.5kw array made 500 watts for the day due to cloud cover).

    Here, with a LFP battery pack, I would be running the genny for less time due to charging efficiency as well as not needing an absorb cycle.

    So savings on fuel counts in favour of LFP. (My fuel costs for the generator were in the $50 range last year.)

    Assuming that the many tests of LFP battery life prove correct in real world use, the lifespan cost advantage of LFP as well as the fuel savings, becomes even more apparent, no?
  • ReedReed Solar Expert Posts: 55 ✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    We have almost the exact same setup as Karrak on our 5th wheel: 16 x 180 Ah cells, 1420 W of panels etc. Ours is an automated system. We "harvest" 3 to 6 kW-hrs a day depending on time of year, weather and power management requirements. Sunny summer days we run the fridge and hot water heater on solar/battery bank. On rainy days we run these on propane. If overcast a lot, then we turn off the inverter when not in use.

    We are full-time RV'ers and have hooked up to line power on three separate days in 17 months. We were in full shade at RV parks. We have only stayed in RV parks when visiting relatives near large cities and boondocking/mootchdocking was not possible. We have lasted 7 days in full shade boondocking in the Olympic Rain Forest, WA and Cave Creek, AZ.

    Reed
  • creekycreeky Banned Posts: 31
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    I stand corrected. The free shipping offer seems to have expired. Shipping is now 200 bucks.

    I will buy the complete package. The idea of a super low maintenance plug and play battery pack appeals to me. Esp. If I can eke out 13-15 years of life.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    creeky wrote: »
    I stand corrected. The free shipping offer seems to have expired. Shipping is now 200 bucks.

    I will buy the complete package. The idea of a super low maintenance plug and play battery pack appeals to me. Esp. If I can eke out 13-15 years of life.
    I had them price out a a pre pack and it was no $200.

    Attachment not found.
  • creekycreeky Banned Posts: 31
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    ah. I was going by the website. when I ordered the pack it added 198 in freight.
    I don't understand your price tho. The 9tr is 3350. Your quote is 2142 and your weight
    is higher than the 9tr.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    creeky wrote: »
    ah. I was going by the website. when I ordered the pack it added 198 in freight.
    I don't understand your price tho. The 9tr is 3350. Your quote is 2142 and your weight
    is higher than the 9tr.
    I didn't tell you what I wanted a quote on, that you don't need to know. You think they are going to ship that battery to you in Canada for $200 ?? That may be the brokerage fees. My quote was for the middle of the USA.
  • karrakkarrak Solar Expert Posts: 326 ✭✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    Photowhit wrote: »
    This would be an okay assessment if off grid solar used the complete capacity every day, unfortunately for the assessment, off grid requires a lot of reserve and it is minimally used.

    If it proves out that in a LiFePo's life is they will deliver the Kwhs over time then your assessment would not be bad. ...but if you typically need 4Kwhs a day but need 20 kwhs reserve and they both last the same time frame in the assessment, LiFePo become much more expensive.

    I guess what I'm saying is you've done an assessment of the cost of available Kwh's not on typical use. Your assessment favors systems that have a regular discharge and charge cycles, off grid solar doesn't. It might if you include the cost of a generator and fuel... that doesn't work for me.

    I don't think there is such a thing as typical use. Some people go for small battery banks and oversize the solar arrays and/or have a generator, some might oversize the battery, then there is load management or a combination of all of these.

    I don't have a generator either, my average daily usage in winter is around 2.5kWh, the average supply from my 1140 watts of solar panels is not much more than this and my nominal battery capacity is 9.36kWh.

    You are right in saying that in my application I don't use the 65% that I could draw from my battery each day and so the cost for me would be more. The big saving I have is that LiFePO4 batteries are not degraded being kept at an SOC less that 100%, in fact it increases their lifespan, so in my case I can use the battery to buffer the input from the solar panels over a long period of time. Over the last winter there was a spell of five weeks between my battery being full with the average SOC being around 40-50% going to a minimum of 15%.

    Simon
    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
     

  • PhotowhitPhotowhit Solar Expert Posts: 5,655 ✭✭✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    creeky wrote: »
    I'm sorry Photowhit, but I don't understand what you are saying.

    In my case, I typically use 2.5 to 3 kw/day. Why would I need a 5x reserve?

    My solar system off grid uses a regular discharge/charge cycle. I use my power every day. I recharge every day. The advantage of LFP batteries here would be the 20% or so increase in charge efficiency. Reducing the times I need to use my generator (note. due to the size of my solar array I only use the genny in the late fall/early winter when heavy cloud in my area reduces solar production ... ie: two days ago my 1.5kw array made 500 watts for the day due to cloud cover).

    Here, with a LFP battery pack, I would be running the genny for less time due to charging efficiency as well as not needing an absorb cycle.

    So savings on fuel counts in favour of LFP. (My fuel costs for the generator were in the $50 range last year.)

    Assuming that the many tests of LFP battery life prove correct in real world use, the lifespan cost advantage of LFP as well as the fuel savings, becomes even more apparent, no?

    That's fine, just include the cost of your generator as your system isn't sized for your year round needs. Mine is...

    I use around 3.5-4 Kwhs in the winter, and 15-20 Kwhs in the summer. Most have a higher use in winter as you do. I'm sized so I don't need/use a generator.

    On another note, he has chosen some of the highest cost lead acid batteries, so if someone wants to argue higher costs for lead acid, I'll point them to $80 GC batteries at the same capacity. If not abused I'd expect Trojans to last 7 years and have abused these cheap GC batteries and gotten 5 years out of them.

    For home systems you will find lift batteries are more cost effective than the GC batteries you've compared for larger systems, and likely more cost effective than GC batteries as well.
    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.
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    creeky wrote: »
    I'm sorry Photowhit, but I don't understand what you are saying.
    In my case, I typically use 2.5 to 3 kw/day. Why would I need a 5x reserve?

    1. Becasue the sun does not shine the same each day.
    2. Becasue we tend to be interested in RE.

    Now that PV prices are much lower it makes sense to offset reduced storage with increased generation. Thats what the likes of PW and I have done. But you still end up with more storage than you need for a single night period. To fix that would require 10 times or more PV.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    zoneblue wrote: »
    1. Because the sun does not shine the same each day.

    Some days it shines so poorly it may as well not bother.
    Some folks ('self included) would rather not run a generator ever.
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • creekycreeky Banned Posts: 31
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    Sorry guys. I must be slow. But I still don't know what some of you're talking about.

    I understand karrak perfectly. He has a solar system(s) that work for him. That i not only understand but enjoy. I have the same. He describes the benefits of his system. Excellent.

    Then I see a post I don't understand. You see I live in an area where heavy cloud limits solar production for 2.5 months. I have 1.5 kws in panels on two controllers. I have had a day when I made 0 watts for the full day. So MtnDon, I could have had a much larger array and it would have not made a difference. Having 5 times the battery storage would help for a day or two, but ... the cost.

    Zoneblue. On your point 1: I think you are making the same point I tried to. It's wonderful to think we will never need a generator. I have one. I also overpanel (soon, like next week) both of my controllers. My first controller has been over paneled due to the cloudy season for 5 years. So we are in full agreement on your point 1.
    Point 2. I have been full time off grid RE for almost 5 years (Dec 18 kids!). I am greener than green. There are lots out there who can out do me. But I wild harvest; I maintain two forests for CO2 offset; I protect acres of bird habitat (for, amongst others, bobolinks, an endangered species); part of my property is recognized as world class habitat. I compost poo (and other stuff). I live simple. Your RE comment was, perhaps, misapplied in my case.

    I simply have a problem with arbitrary numbers/etc denigrating intelligent decisions. I have seen many examples of this. Case in point, Blackcherry04 declines to say why his order cost double what the website said it should after he posted a link to the 9tr system. Assumptions about which he previously erroneously described. Fine and well. We all make mistakes. He then "assumed" that I was shipping to Canada. This is an assumption. I have seen many such here. I ship to the border which I live minutes from.

    This is something some of you guys need to get a grip on. Are you RE solar guys or are you leadites clinging to solar practices of the past?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    creeky wrote: »
    This is something some of you guys need to get a grip on. Are you RE solar guys or are you leadites clinging to solar practices of the past?

    Realists who do not automatically assume LiFePo is the perfect answer for everyone.
    Many of the 'advantages' of the technology simply do not apply to the average RE user. No two systems are alike, nor should they be. Available sun and usage patterns go a long way towards determining how a system is designed, regardless of the components involved. When examining options it has to be on a case-by-case basis.

    And if you can't manage lead-acid batteries the LiFePo is simply an opportunity to make even more expensive mistakes.

    So when one of the forum members says LiFePo is too expensive for them, don't tell them they are wrong. Mindless cheering for a 'panacea' technology doesn't wash.
  • PhotowhitPhotowhit Solar Expert Posts: 5,655 ✭✭✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    creeky wrote: »
    I have been full time off grid RE for almost 5 years (Dec 18 kids!). I am greener than green.

    Do you understand that if you have the grid available it is likely you are likely less 'green' with an off grid system than connecting to the grid?

    I'm no leadite(or Luddite), I just can do the math! Now if you want some real challenging numbers, compare a LiFePo battery with a Forklift/Traction battery, with a similar depth of discharge ability and a similar (and proven 15-20year!) life span. 800Ah 24 volt $2525 delivered give me that capacity in a LiFePo battery for a similar cost....

    ...or perhaps try to understand what we are saying instead of challenging us. Did you run the numbers with $80 a battery Costco or Sams club batteries even at 5 years life span?

    FWIW - I've been off grid for 14+ years now and I really think LiFePo batteries already have a place where weight and charging efficiency is a problem, RV can often benefit here on both counts.

    I'm cheap, don't know if anyone has done it cheaper, believe me if LiFePo batteries can save me money, I'd own one! Perhaps it will be my next battery 10 years from now!
    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.
  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    creeky wrote: »
    So MtnDon, I could have had a much larger array and it would have not made a difference. Having 5 times the battery storage would help for a day or two, but ... the cost.

    I thought the question was why would someone need several times their average daily use in reserve. That's not array size, that's storage size. Countering cloudy non productive days takes either more storage or running a generator, or of course curtailing use.



    There are times I wish the power grid had been closer to us. Measured in $$ the distance was $55K in 2007. That determined going off grid. Some extra capacity in FLA GC-2's did not cost all that much comparatively. At present we are happy with what we have. We may need replacements in a year, maybe 2 or 3... we'll see. Then at that time we'll see if we stay with GC-2's from Sam's Club, go with a string of L-16 or, who knows, LifePO4. Much can happen in the next year or so.
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    creeky wrote: »
    I simply have a problem with arbitrary numbers/etc denigrating intelligent decisions. I have seen many examples of this. Case in point, Blackcherry04 declines to say why his order cost double what the website said it should after he posted a link to the 9tr system.

    Too Funny !!!
    creeky wrote:
    According to the Balqon website, their price includes shipping, as well as the BMS, the disconnector for over/under voltage, the racking etc. BlackCherry04 you might want to go to the site and have a look at the specs and package.
    I did what you asked me to do, I went to their site and looked. They showed 4 Packaged batteries 2.6 kw ($1,430 ), 9kw ( $3,350 ), 15kw ( $5,250 ) and a 18kw ( $6,650 ). I posted a link for the 9kw packaged battery, no where did I say I bought that battery. I arbitrarily posted the link so everyone would see what you were talking about. The only thing I posted back to your request above is that I saw no Shipping Included. All I posted was a quote for some number of cells and some other parts, it showed the shipping charges. As far as where you might have a battery shipped, who cares. The point about having the battery shipped to Canada is because the shipping charges that come up on the shopping cart were estimated without them even asking for a shipping delivery address, how could they estimate shipping ?? If you want to call it a assumption, go ahead.

    I would like to know more about what Balqon is selling and what posters would think is a value for their money. What are the actual Amp Hrs of the battery ?? How many cells are in it and what are their size ??

    Please tell us about your LiFep04 system, since you post about LiFeP04 batteries, you must have them or is this just a assumption on my part ??
  • karrakkarrak Solar Expert Posts: 326 ✭✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    Photowhit wrote: »
    I'm no leadite(or Luddite), I just can do the math! Now if you want some real challenging numbers, compare a LiFePo battery with a Forklift/Traction battery, with a similar depth of discharge ability and a similar (and proven 15-20year!) life span. 800Ah 24 volt $2525 delivered give me that capacity in a LiFePo battery for a similar cost....

    ...or perhaps try to understand what we are saying instead of challenging us. Did you run the numbers with $80 a battery Costco or Sams club batteries even at 5 years life span?

    You could do the figures on other batteries and post them. I am sure lots of forum readers would love to see more data on this as long as it is backed up with documentary evidence. I did the figures on the T105s as they seem to be a generic well respected FLA battery which I could get good data on.

    I don't know what brand of Forklift battery you have and if that price is 14 years old. I looked at the Crown forklift batteries from NAWS. The costing on this one http://www.solar-electric.com/batteries-meters-accessories/batteries/crdecyinba1/crinba1/24voinba/crinba24vo78.html which is a similar size to yours is ~$205 /kWh. The only information I could find on the Crown website for these was 1500 cycles or 4-8 years life which I assume is for forklift use. I have no experience with these batteries but would think you would have to limit your discharge to 20-30% to get anything like 15-20 years of use from them. For 30% cycling we get a cost of ~$685 /kWh and say it lasts for 20 years gives us ~$34 /kWh/year. I wonder where this cost ends up when you add in the cost of extra solar panels and charging hardware to get around the poor efficiency, charging requirements and amount of usable storage of these batteries.

    Simon
    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
     

  • PhotowhitPhotowhit Solar Expert Posts: 5,655 ✭✭✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    karrak wrote: »
    I wonder where this cost ends up when you add in the cost of extra solar panels and charging hardware to get around the poor efficiency, charging requirements and amount of usable storage of these batteries.

    It works out just fine, if fact better for off grid solar! You need the capacity but you don't need it every day, so the fact that these can be taken down to 20% SOC means you have the capacity (similar to your LiFePo) but in off grid situations you rarely need to go that deep (once this year to @30%) but I also don't need a generator. So if they can deliver the capacity and they have the longevity they work out nicely.

    With out the capacity I might get by with a smaller array, but I would need a generator. I don't need the higher charging efficiency, I have room for panels on a ground mount fixed array. If they are 15% more efficient I'd say I might need 10% larger array, but even giving you the 15% it doesn't compare to the more than double the cost of the battery.

    Battery price is current! Though the price list is 3 years old it has been checked this year by others. I used a 15 year life span when I did my analysis of costs reports of forklift batteries life spans start around 15 years and some reports of 30+ years were ignored. The cost analysis doesn't include the cost of a woodstove, or maintenance, or the $2500 tax credit here in the US.
    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.
  • karrakkarrak Solar Expert Posts: 326 ✭✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    Photowhit wrote: »
    It works out just fine, if fact better for off grid solar! You need the capacity but you don't need it every day, so the fact that these can be taken down to 20% SOC means you have the capacity (similar to your LiFePo) but in off grid situations you rarely need to go that deep (once this year to @30%) but I also don't need a generator. So if they can deliver the capacity and they have the longevity they work out nicely.
    .

    How often do you think you can take the battery down to 20%-30%SOC, how long do you think you could leave the SOC at these levels and what would be the average SOC that the battery would have to stay above to get 15+ years life from them?

    Simon
    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
     

  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    I think an analogy might help....

    Many decades ago I had a Roberts reel to reel tape recorder. Sony introduced the first CD player. It held a single CD. A friend bought one of the first for something like $1500 Canadian dollars. Back then the dollar was a little "larger". He loved his CD player. I really liked the sound of his new expensive CD player. But I never bought one as I could not see throwing that kind of money at one.

    Over the ensuing decades I did buy a CD player, then a multi disc unit, then a burner. Now my music is on a hard drive and memory cards. Things change over time. Some changes take a while to be widely accepted. Price is one of the leading governing factors. There are always some who are willing to pay the high costs for being near the head of the line.

    There were other technologies explored along the audio road from 78's to today's digital downloads. Perhaps another reason for not jumping into new technology is exemplified by the 8-track tape.

    Anyhow like back in the days of the new CD technology, I am not in a hurry to adopt newer battery technology until the price gives me more reason.
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • ReedReed Solar Expert Posts: 55 ✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    Mountain Don

    Your analogy is rather correct. The technology for advanced batteries is increasing and there are indications that the prices may drop by 50% in the next several years. Our current LFP battery bank will probably be as dated as 8-track stereo in a few years. The Chinese universities are doing rather good work. The below was noted on a New Zealand RV forum that I follow

    http://media.ntu.edu.sg/NewsReleases/Pa ... ae4c50c934

    Reed and Elaine
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    How often do your FLA batteries come out looking like this after a .02 volt overcharge ??

    Attachment not found.
  • PhotowhitPhotowhit Solar Expert Posts: 5,655 ✭✭✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    karrak wrote: »
    How often do you think you can take the battery down to 20%-30%SOC, how long do you think you could leave the SOC at these levels and what would be the average SOC that the battery would have to stay above to get 15+ years life from them?

    You make my point for me!

    While I only NEED to take it down that low a couple times a year, while in use as a forklift battery they go between 20 and 50% SOC daily for 5-8 years. I do keep track and want to be above 80% SOC daily. I have not gone more than a couple days below 50% SOC (not more than once so far). I fully expect and lift batteries have history, that they last 15+ years.

    I am NOT the person that says LiFePo batteries don't have a place currently, but they cost more than lead acid now for a fixed home system.

    For What it's worth, 8 track as a consumer product is dead, but the Fidelipac type cartridge lived on for many years after the consumer death as 'carts' in radio stations, they had unique features as being self rewinding (endless tape really) so they were used for radio commercials until being replaced by digit audio well into the current century!

    Right now LiFePo has it's place, and I don't doubt that it will become cheaper over time and may prove to be very reliable and has the potential to last a very long time. Perhaps, if your batteries live 30 years, you will have made a better choice. If I got ill or had to leave home for an extended period of time (2-3 months) the routine maintenance that is required could be interrupted and damage or even kill my battery, so you might have an advantage there.

    As I said before they have a place where weight and efficiency. We recently had a fellow post about his 18 kwh RV battery setup, I bet he wishes he had gone with LiFePo batteries!

    All in all I'd rather have a "talking frog..." the known, verses the possibility of a prince.
    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: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    How many of you LiFePo users have been using them in a stationary off-grid application for 20+ years? Until that is done the claimed lifespan is just a claim, not a fact.

    Prices for anything are not the same all over. Costs quoted for Australia are not for the USA nor for Canada. Certainly not for Canada. Oh boy not. We wish! It also seems that places such as Europe, Australia, and Japan have higher availability for new technology than "we've always done it this way" USA. As such they can get certain things cheaper.

    Has anyone tested these batteries to destruction? People know what to expect with lead, yet still ignore the facts of it and murder them. I've heard idiots proclaim lead-acid "doesn't work for RE" in the face of the thousands of systems using them economically for many years. What they really mean is they screwed up every time and ruined the batteries, and so they wish to blame the technology for their ignorance.

    Here are the facts on LiFePo gleaned from the hyperbole:

    1). lighter weight than lead, which is not exactly important in non-mobile applications.
    2). greater tolerance of low/varied SOC, which is fine except that a discharged battery has not got full power no matter what it's made of. This would be good for remote apps that can't be checked where and accident would leave a lead battery dead and unrecoverable or in a case where charging is highly varied and unpredictable (compensating for poor utility power for example).
    3). the initial cost is significantly higher, which is prohibitive for the available capital of many.
    4). claimed lifespan not yet proved. Never mind laboratory tests; the lead-acid makers have them too and they don't always pan out.
    5). there may or may not be the need for per-cell management which can be an additional complication/expense.
    6). what happens when things go wrong seems to be a topic advocates wish to avoid. I suspect that, like AGM's or GEL's, they are fatally intolerant of mistakes in settings.
    7). not all existing RE equipment can be used with them due to the difference in operating Voltages; you need controllers and inverters that can be fully programmed to the right level.

    As with any and all equipment you can NOT say "this is better than anything else and everyone should be using it". I would especially warn against newcomers starting out with LiFePo due to the very high likelihood of the batteries being ruined just as so often happens with standard batteries. Too many people have bought AGM's first and fried them due to high Voltage or killed them dead due to excess discharge in the very first year. Others manage 8 years from El Cheapo GC2's. Lifespan is not as easily predicted as makers would have you believe.

    I'm probably going to have to lock this thread as well as it deteriorates into ranting hyperbole like the others did. This time I will be handing out suspensions.
  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    Photowhit wrote: »


    For What it's worth, 8 track as a consumer product is dead, but the Fidelipac type cartridge lived on for many years after the consumer death as 'carts' in radio stations,


    Much like the Betamax video cassette lived on in broadcast TV news for years after it disappeared from the consumer market.
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries
    creeky wrote: »
    Your RE comment was, perhaps, misapplied in my case.

    My point two was a not so subtle swipe at gensets in RE systems (not going to get into a discussion about who or what is greener). However the fact is that in order to best utelise any kind of lithium storage setup, a generator is required. Cut the storage down to the bare bones, cycle the snot out of the bank, and use the genset to cover the weather vagaries. With lead you cant cycle the snot, so you end up with the reserve, so therefore you can dump the genset more easily. Sad but true.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • creekycreeky Banned Posts: 31
    Re: Comparative specifications of LIFePO4 & Flooded Lead Acid batteries

    hyperbole: exaggerated statements or claims not meant to be taken literally. I assume ;) this is meant to be a poke at those who made assumptions. ie: I would be greener to be ongrid.

    Cariboocoot. Thank you for pointing out some of the facts about LFP. It is lighter. It does "appear" it will last longer. It does require less maintenance. It does not suffer from voltage sag the way FLA does.

    Note: Thanks to the useful posts I have seen here on previous threads; My solar set up will work easily with LFP. My Morningstar mppt-60s are programmable (in fact I had to program them to match my Crown battery settings). My inverter, the TBS, handles 10.5 to 16v with aplomb. I know because I once equalized and unknowingly the cold batteries required 15.7v. My Morningstar posted a high voltage of 15.9 but the fridge ran on.

    Luckily facts are facts. With a simple google search and the help of Reed I have found many tests: LFP packs to -75C (won't light a lamp at that temp) and many many tests at 100% dod and 2000 cycles. I think we can take it that LFP is here to stay. And -20C appeared reasonable for my needs.

    As for cost: a 2015 Tesla is pricier than most SUVs and you will never get your money back on gas savings. So? You can get a cheaper meal at McDonalds than the Keg and you will never get your money back. Cost is only one factor.

    LFP is ideal for the first time solar user because it doesn't need as much maintenance. In my case: I have to travel for up to 4 months at a time every year. Which would you want to leave at home. A $4k battery pack that won't be harmed if left unattended. Or a $2k battery pack that will self discharge and sulfate if not charged regularly? Fingers crossed I've been lucky. Tho in 2011 I had a heavy snow fall/then rain block my panels and my batteries eventually ran down to 11.9. Ouch. It was only for a short period. But still. And nothing I could do. I was 2000 miles away.

    Blackcherry04. This is what I have asked for: real data, unbiased presentation, actual documentation. I am sinking a considerable sum into a battery pack. What I need are facts. Could you post a link to documentation on the photo verifying your .02v claim. And yes, you make another assumption I'm afraid. If you read my posts you will see I have only been asking for user feedback and usage parameters. 'Cause, let's be honest, LFP looks good.

    Thx MtnDon for the excellent analogy. Made my day.

    And thanks again Karrak for the excellent post. I really appreciate your and others' (Reed etc) actual user feedback and knowledge.
This discussion has been closed.