Time to change up to LiFe Po4 batteries?

icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
Greetings folks, be away from the forum for far too long, and indeed the technology has run past me.  I have a question that perhaps a discussion will reveal the answer to.

I run a fairly small off grid system, with ~600 watts of PV.  It is currently used seasonally from ~M<ay 1-Oct 30 when it then sits idle and unattended.  I have been running 4 T-105s that are getting tired, they are currently on year 11 however!.  I consume ~1-1.5 KWH/Day and easily put that back in along with time shifted loads to power the house during the day.  I have never routinely drawn the system down below ~80, and have ~3 days of autonomy before getting into the 70% range.  The T105s are wired 12 vdc for ~500 ah 20% of that is ~100ah.

Replacing the T 105s will cost me ~ $600 for another set.  Alternatively I am considering a 100ah 12 vdc LiFe battery like our sponsor sells, for ~$950.  A couple of questions to start.  First, how well will they handle daily cycling to as much as 50% which would be the max daily draw generally.  Second, how would they handle long periods of (very cold, -40) inattention?  

My intuition (not knowing a damn thing about LiFe batteries!) is that it would be a bit too small and I would be disappointed or overly protective of the small capacity.

All comments welcome.

PS. I am all well, just chasing life.  I just finished a 1kw 24 vdc, off grid system for a friend.  Boy the price of the hardware (and quality) sure has come down.  (Except batteries). The first off grid PV system I build, the PV alone was ~$10/watt, now under $1!  Same with controllers that have better features and reliability, inverters etc.

Best to all,

Tony

Comments

  • TecnodaveTecnodave Registered Users Posts: 418 ✭✭✭✭
    edited May 2019 #2
    Two considerations that come up......can't charge LiFePO4 at or below freezing.......do not let voltage drop too far, they will be destroyed and won't accept a charge.......but I'm FLA........that is where my expereince is, ...I do have set CALB LiFePO4  40 a.h. For portable power use, only 1 year expereince with LiLo, LiPo, and LiFePO4.......just tinkering.  Have several hundred 18650's and can charge dead ones and bring them back......Tinkering with Ni-Cad wet cell, have 10 cell Edison ED-80  12 volt 80 a.h. bank

    .I'm native Alaskan but gave up that environment for coastal California years ago, saw 70 below and colder for 96 days in a row,(Fairbanks)  that was more than enough. I can't stand Fresno 90 degrees in the shade, farm workers in the fields at 109 degrees.....I'm so close to the ocean that I might fall in....Santa Cruz County
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Well, if you can’t charge them below freezing, that seals it.  Mine will sit below freezing for 6 months at a time.  I still have ice here on May 17!  Tony
  • EstragonEstragon Registered Users Posts: 4,478 ✭✭✭✭✭
    I'm eventually going to be in much the same boat. I really kinda want to want lithium, but there are some things nagging.

    AFAIK, cold storage (ideally with partial SOC) is ok, so would need to shut down completely for winter.  Any security/monitoring would need other power, and any winter use would need a way to warm the bank.  With LA, even arriving at -30°, I can just flip the breaker.

    My main issue is cost vs usable storage, which has two main parts. 
    First, I know a smaller bank can be used, but while I don't run my LA bank <50% SOC, somehow it's nice to know the capacity is there to do so should it ever come to that.  Lithium goes from fine to dead at low SOC.  LA has some wiggle room.

    The second is real-world cycle life vs lab/theoretical life.  If they really last as long as claimed, the upfront cost makes more sense.

    If I had to replace batteries today, I'd have a hard time picking lithium, but that may change once there's more real world experience out there.


    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • Ralph DayRalph Day Solar Expert Posts: 914 ✭✭✭✭
    Good to see you back Tony!  Been a while.
    I just replaced my CS plate 8v Surrette batteries in April.  They were sulfated and really tired with not much capacity left.  That was ok, I have utility power available...but any amount of discharging and charging and the electrolyte would be at 40degC.  Replaced with Surrette S550's (L16).  Still breaking in and getting used to them.  Long absorb times (5+ hours) but at 1.1 or 1.2 amps for much of that time.

    One thing about lithium is they're light.  I picked up a Group 31 lithium at Solacity when I picked up my S550's, it weighed 31 pounds.  You could bring them in and out on a boat with no problem.  Just a thought.  Mind you, they're $1200CDN each.

    Ralph
  • Raj174Raj174 Solar Expert Posts: 751 ✭✭✭✭
    edited May 2019 #6
    Hi Tony,
    I have been using a DIY Lithium battery bank for 3 years. It is a pleasure and I would not use anything else, they are well worth the money. I believe that your intuition serves you well and agree, two 100AH batteries in parallel would be necessary to replace your bank. This type battery has an internal BMS that protects it from being charged or discharged outside the safe temperature range. It is also protected from over voltage charging and has an internal low voltage shut down. Although it is advertised as a 100AH battery, it is really about 120AH because you can use the full 100AH before the BMS shuts down the battery, so with a 200AH bank, very near 200AH is available. A DIY bank would be about 500 dollars cheaper, but If you don't want to, or don't have the time to investigate LIFePO4 chemistry along with the experiences and recommendations of other DIY Lithium folks then a Battle Born type battery is your best and safest bet IMHO. 

    Rick   
    3600W PV, MNE175DR-TR, MN Classic 150, Outback Radian GS4048A, Mate3, 54.4V 195AH LiFePO4, Kohler Pro 5.2E.
  • mcgivormcgivor Solar Expert Posts: 3,407 ✭✭✭✭✭
    Made the change to LFP eight  months ago after much research and apprehension, the conflicting information was initially a stumbling block, however I soon discovered much of it was hearsay, echoes of what was read or haerd. 

    The initial plan was to replace the LA bank with a like capacity even though there was nothing wrong with them, they could be re purposed, which they are. Looked into the drop in replacement type initially, such as Battleborne, but chose the prysmatic route, not that there's anything wrong with them, just seems simpler with 32 cells rather than hundreds of cells. So I took the plunge with 32 ×100 Ah cells, the cost, including shipping, BMS and all nessersary equipment was approximately double 8 T105 GC batteries.

    Realistically 400Ah of LA is only 200Ah, whereas 400Ah of LFP is a very conservative 280Ah, for a generous cycle expectancy, so this has to be considered in the pricing, it's not apples for apples. Granted the pre assembled batteries come at a premium, which is where choices are made as to which way to go. The DIY bank is amazingly simple to assemble and ballance, once done the maintenance is far less labor intensive than a LA bank, reference to wet cells, the charging is faster due to no absorption stage and no worries about not achieving full charge as they tolerate partial states of charge well.

    The question of low temperature is not something I've personally had to deal with, but with some creative thinking it's not something that couldn't be solved with some insulation and a source of heat, it wouldn't take much to keep above freezing. Having said that if left disconnected the  temperature along with low self discharge will have little effect, they will recover when temperatures rise above the threshold.

    Lead acid batteries are something I'll never return to, howeverl given their history as the stalwart of energy storage they are not something  to be ignored and they do have many positive aspects, but not enough to warrant staying with them, just my opinion.

    Thanks again to @Raj174 and @karrak for the support which was extremely valuable in my endeavors.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,185 ✭✭✭✭✭
    icarus said:
    Greetings folks, be away from the forum for far too long, and indeed the technology has run past me.  I have a question that perhaps a discussion will reveal the answer to.

    I run a fairly small off grid system, with ~600 watts of PV.  It is currently used seasonally from ~M<ay 1-Oct 30 when it then sits idle and unattended.  I have been running 4 T-105s that are getting tired, they are currently on year 11 however!.  I consume ~1-1.5 KWH/Day and easily put that back in along with time shifted loads to power the house during the day.  I have never routinely drawn the system down below ~80, and have ~3 days of autonomy before getting into the 70% range.  The T105s are wired 12 vdc for ~500 ah 20% of that is ~100ah.

    Replacing the T 105s will cost me ~ $600 for another set.  Alternatively I am considering a 100ah 12 vdc LiFe battery like our sponsor sells, for ~$950.  A couple of questions to start.  First, how well will they handle daily cycling to as much as 50% which would be the max daily draw generally.  Second, how would they handle long periods of (very cold, -40) inattention?  

    My intuition (not knowing a damn thing about LiFe batteries!) is that it would be a bit too small and I would be disappointed or overly protective of the small capacity.

    All comments welcome.

    PS. I am all well, just chasing life.  I just finished a 1kw 24 vdc, off grid system for a friend.  Boy the price of the hardware (and quality) sure has come down.  (Except batteries). The first off grid PV system I build, the PV alone was ~$10/watt, now under $1!  Same with controllers that have better features and reliability, inverters etc.

    Best to all,

    Tony
    Great to hear from you Tony ! Any icicles for cocktails tonight?
    You are a sealed deal with the temperature. Stay with LA golf batteries and their known characteristics. Go 48v and double the cost ;)

    I have a client not far from you who had to leave home for a funeral. He could not get back for a week as the road washed out.
    The battery logged the temperature and warranty was void on a 13,000 dollar battery. Ouch!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Funny you should mention iceicles!  No icicle anymore, although it was -4C last night.  Our ice went out late last week.  I still have ice piled up on the shore since it has been so cold still.  Today is sunny and clear, but only ~+5C.  I’ve got a short video that is pretty spectacular, and will post if I have enough bandwidth.  T
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    A few more to keep you chillin’.  Top, the island I live on..from a boat...I”aint walking on that ice.  See the ice piled on the shore?  Middle, the same ice pile from the shore, 15’ high, 25’ onto the land in some places.  Bottom, same ice pile.  Those slabs are ~5’ square, 12” thick.  The force put on the shore is tremendous.  (I can’t seem to post any video, any suggestions?  Maybe it violates forum rules?  T
  • BB.BB. Super Moderators, Administrators Posts: 30,520 admin
    Upload to YouTube, make public, paste the link here (if you hit enter after three link, the forum will bring up the YouTube player).

    Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • PhotowhitPhotowhit Solar Expert Posts: 5,183 ✭✭✭✭
    edited May 2019 #12
    Good to hear from you Tony!

    I'll share a short info thing I did for Solar discussions on line;

    Lithium vs Lead Acid
    While LiFePo4 can be discharged 80-90% and they last a long time, they are still more expensive than lead acid for off grid use. In off grid use we need to have a reserve capacity, usually 4-5X our daily use for cloudy days.
    We try to stay in the upper 20-25% in daily cycling. But use the extra capacity when needed. Lead acid forklift batteries are often discharged below 50% daily for years. Golf cart and any 'true' deep cycle can be discharged 80%, but your number of discharges to this state are limited.
    This is roughly how I works.
    Lithium may get 3x the amount of cycles if compared. Some are claiming they will last 10,000 cycles, which may be true, but cost as much as 10X. Lithium will basically tell you they are not, yet, cost effective for off grid solar use.
    Here are 2 statements cut and pasted from the linked site;
    "Let’s compare a classic in the off-grid solar world, the Trojan T-105 flooded lead acid battery. It’s 6V, 225Ah (amp hour) for a total of 1350Wh (watt hour). It costs about $160. We’ll compare that with the SimpliPhi 1310Wh 12V, 102.4Ah, that costs about $1750. I know, that’s 10x more for almost the same capacity battery,...."
    "That means, you will have to replace the lead acid batteries more than 3 times to get the same life cycle of the SimpliPhi batteries"
    They make it LOOK like lithium are a better value, because they say you don't need as large a battery. But if you don't have the reserve capacity, you will need to run a generator or other supplemental charging sources. Requiring a generator and gas to supply expensive energy and that savings on maintenance will go into servicing the required generator.
    Lithium is likely the future of batteries, but it will have to be much less expensive, to be cost effective for off grid use.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • mcgivormcgivor Solar Expert Posts: 3,407 ✭✭✭✭✭
    edited May 2019 #13
    @Photowhit I do understand these were not your statements just cut and paste from elsewhere.

    First statement 
    Let’s compare a classic in the off-grid solar world, the Trojan T-105 flooded lead acid battery. It’s 6V, 225Ah (amp hour) for a total of 1350Wh (watt hour). It costs about $160. We’ll compare that with the SimpliPhi 1310Wh 12V, 102.4Ah, that costs about $1750. I know, that’s 10x more for almost the same capacity battery,...."

    This is a misleading statement, the Trojan T-105 is really 675Wh assuming 50% DOD, the Simpliphi is 1048Wh assuming 80% DOD 
    To get 3000 cycles according to Trojan the DOD should be no more than 20%, the Simpliphi is rated at 10 000 cycles at 70% DOD. The energy lifespan  of the Trojan  would be 810 000Wh, by comparison the Simpliphi would be 9 170 000Wh, which would mean the Trojan bank would have to be 3.7 times greater nominal capacity, replaced 3 times so actual cost would be $1776 pretty much the same.
    The pricing for the Simpliphi is probably calculated to be competitive with LA,  but they are definitely not the cheapest way to go, using prysmatic cells with a good reputation such as Calib or Winston would cost ~$500 for 4 100Ah cells, others can be half that, that is where the true savings become apparent. There is of course some work to be done along with the cost of a BMS  ~$100 for a digital unit, but it is all reletivaly simple given an electrical background.

    Second statement 
    They make it LOOK like lithium are a better value, because they say you don't need as large a battery. But if you don't have the reserve capacity, you will need to run a generator or other supplemental charging sources. Requiring a generator and gas to supply expensive energy and that savings on maintenance will go into servicing the required generator.
    Lithium is likely the future of batteries, but it will have to be much less expensive, to be cost effective for off grid use.

    To have the reserve capacity needed is merely a calculation, the nominal capacity of LFP may well be less by comparison to LA primarily due to the ability to operate at higher DOD without adverse effects. To have autonomy with LA a significantly sized bank is required to limit DOD, the problem is when the sun returns, it's likely the charging capacity is not sufficient to recover the lost capacity so a generator is still probably needed. LFP can take all the time needed because there is no threat of sulfation.
    With regards to charging LFP can be charged at 1C, flooded LA is typically ~0.5C, which means a larger array could be used, this also allows shorter run times if a generator is required, additionally there is no absorption stage, the most important and inefficient stage. Obviously it would be unwise to size any battery to be marginal, an error commonly made with any battery chemistry.

    The above statements are typical misconceptions, one needs to really calculate before simply looking at primafcaie numbers, not included are the  maintenance costs of watering, labor involved or inherent pass through efficiency, LA banks need to be ~15% larger just to compensate.

    Edit: There are recycling value to LA batteries which can be ~10% of the value returned.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • solardadsolardad Registered Users Posts: 23 ✭✭
    @mcgivor
     
    Coke vs. Pepsi, Ford vs Chevy, LA vs LFP

    i think people will always be tied to there favorites no matter what the current information or technology is out there. Agree 100% that LFP is the future now and have been running used EV batteries in my hybrid system, 32 kWh from a Chevy Volt (20-24kWh usable).  I would love to get more but prices have increased on the salvage market from when I bought them 50%+, paid $90/kWh now $130 +. Still much cheaper than other LFP options and hoping for a drop.

    As for cold temps look at leverage earth. My brother is looking at a setup for his cabin where lows are 10 to 20 below. He has a cellar under the cabin and is planning on building his storage bank up against the earth to capture the ground temp.. from an old root cellar that is attached. 

  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    May problem is that I am on a rock Island, with no way to build a cellar.  I can’t even drive a ground rod!  The batteries may sit unattended for weeks at -40.  The bottom line, given the current state of technology, it is FLA for the next round. Between price, availability, safety, known parameters etc it is still no contest.  Tony
  • mcgivormcgivor Solar Expert Posts: 3,407 ✭✭✭✭✭
    icarus said:
    May problem is that I am on a rock Island, with no way to build a cellar.  I can’t even drive a ground rod!  The batteries may sit unattended for weeks at -40.  The bottom line, given the current state of technology, it is FLA for the next round. Between price, availability, safety, known parameters etc it is still no contest.  Tony
    Lead acid would  be the better choice in your case, oddly enough temperature was the reason I switched, but on the other end of the scale +40°C  is where lead acid suffer more, never enough time to cool, LFP don't have the self gain so remain at a lower than ambient during the day, LA will increase to >45°C. So the right tool for the job, so to speak.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • PluckaPlucka Registered Users Posts: 110 ✭✭
    I have noticed as the temperature drops under 25C so does the charging rate from solar panels
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Interesting...I believe in most cases PV output actually increases with lower temps, (or more correctly drops with higher temps.  Are you saying your CC config changes your charge algorithm that way with temp?  Tony
  • EstragonEstragon Registered Users Posts: 4,478 ✭✭✭✭✭
    All else held equal, I suspect decent mppt controllers will increase output at lower temps.  All else rarely being held equal though, I could see output being reduced for the same reason temp is lower (cloud cover, sun lower in the sky, partial shading, etc)
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • BB.BB. Super Moderators, Administrators Posts: 30,520 admin
    Seeing 15%+ improvement harvest with MPPT on cold winter days with 1-2 hours of sun is not going to get the harvest of 5-6+ hour hot days of "full sun equivalent" sun with any controller type.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,185 ✭✭✭✭✭
    No it won't Bill but, an mppt will get more peak power in during the shorter time offgrid foks need it most. Winter. 
    Basking now in May here even with endless storms, the longer power hours make all of the bad parts of winter fade in memory.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • bill von novakbill von novak Solar Expert Posts: 891 ✭✭✭✭
    Plucka said:
    I have noticed as the temperature drops under 25C so does the charging rate from solar panels
    Might that happen because your insolation angle is getting worse at the same time?
  • jonrjonr Solar Expert Posts: 1,371 ✭✭✭✭
    > The batteries may sit unattended for weeks at -40

    This is fine if they aren't being used.   Just don't charge them (although some say that a trickle charge is fine).   Or put them in a super insulated box with a very small heater.

    Evidently most chargers don't yet have a "refuse to charge at less than 0C" option.

    I am available for custom hardware/firmware development

  • TecnodaveTecnodave Registered Users Posts: 418 ✭✭✭✭
    I think that some lithium batteries with built in BMS have a temperature sensor that will record lowest temperature and will void the warranty, I recently read a post where that happened on a brand new set and voided the warranty on a $13,000 battery, can't remember between the brain fog if that was on this forum or one of the others that I read and post on.  I'm much too new with lithium tech to recommend. I'm here to learn and share.

    david
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
  • PluckaPlucka Registered Users Posts: 110 ✭✭
    edited May 2019 #25
    Same time [11 am] late autumn over 4 days  clear blue skies day 1 @ 25 c 25.6 amps --day2 @ 17c  23.5 amps--- day3 @ 19.5c- 24.1 amps--- day4 @ 23c-24.8 amps. This is what gave me idea that colder weather reduced my solar output into 12 volt lithium batteries. Maybe humidity affected my readings?
  • PhotowhitPhotowhit Solar Expert Posts: 5,183 ✭✭✭✭
    edited May 2019 #26
    Plucka said:
    Same time late autumn over 4 days  clear blue skies day 1 @ 25 c 25.6 amps --day2 @ 17c  23.5 amps--- day3 @ 19.5c- 24.1 amps--- day4 @ 23c-24.8 amps. This is what gave me idea that colder weather reduced my solar output . 
    Accepting that those are amp hours harvested and not amps being delivered at solar noon or some other specific time.

    Likely the batteries are reaching full and the charge controller is shutting down. Perhaps on cooler days you don't run the fans much so less draw on the battery so less energy needed to reach full, and, actually, lead acid batteries have more capacity when warm so there is that too...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • BB.BB. Super Moderators, Administrators Posts: 30,520 admin
    Is this a PWM or MPPT controller? While Vmp rises as panels get colder (towards freezing and below)... Imp actually falls very slightly (roughly 1/5 to 1/10 as fast as Vmp rises) and panels get cold...

    But to be honest, it probably would not even be a measurable change in Imp with a PWM controller and "cooler panels"... (2-3% or so decrease in PWM array current at most on a very cold day???).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • South AfricaSouth Africa Solar Expert Posts: 295 ✭✭✭
    Just on the matter of lithium's and temp. Has anyone checked out the RELiON Low Temperature Series?
    The LT Series is perfect for use in cold climates. These batteries can charge at temperatures as low as -20°C (-4°F), with no cost to the performance of the battery.

    See the LT's in this list: https://relionbattery.com/products/lithium
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,185 ✭✭✭✭✭
    A few makes of LFP are using the charge current to heat the battery first. A few makes shut down to protect them self when cold.
    These methods of protection are adding complexity to a power system and new failure modes.
    Losing power offgrid is never a fun thing when it is cold outside.
    Due diligence is required on this one, in my opinion.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • PluckaPlucka Registered Users Posts: 110 ✭✭
    Plucka said:
    I have noticed as the temperature drops under 25C so does the charging rate from solar panels
    Might that happen because your insolation angle is getting worse at the same time?

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